I-band titin in cardiac muscle is a three-element molecular spring and is critical for maintaining thin filament structure.
AuthorsLinke WA, Rudy DE, Centner T, Gautel M, Witt C, Labeit S, Gregorio CC
JournalJ Cell Biol
PubMed ID10444071
'In cardiac muscle, the giant protein titin exists in different length isoforms expressed in the molecule''s I-band region. Both isoforms, termed N2-A and N2-B, comprise stretches of Ig-like modules separated by the PEVK domain. Central I-band titin also contains isoform-specific Ig-motifs and nonmodular sequences, notably a longer insertion in N2-B. ... More
Tyrosine phosphorylation of paxillin alpha is involved in temporospatial regulation of paxillin-containing focal adhesion formation and F-actin organization in motile cells.
AuthorsNakamura K, Yano H, Uchida H, Hashimoto S, Schaefer E, Sabe H
JournalJ Biol Chem
PubMed ID10823820
'Temporal and spatial regulation of actin-based cytoskeletal organization and focal adhesion formation play an essential role in cell migration. Here, we show that tyrosine phosphorylation of a focal adhesion protein, paxillin, crucially participates in these regulations. We found that tyrosine phosphorylation of paxillin was a prominent event upon integrin activation ... More
Signaling complexes of the FERM domain-containing protein GRSP1 bound to ARF exchange factor GRP1.
AuthorsKlarlund JK, Holik J, Chawla A, Park JG, Buxton J, Czech MP
JournalJ Biol Chem
PubMed ID11445584
'GRP1 is a member of a family of proteins that contain a coiled-coil region, a Sec7 homology domain with guanosine nucleotide exchange activity for the ARF GTP-binding proteins, and a pleckstrin homology domain at the C terminus. The pleckstrin homology domain of GRP1 binds phosphatidylinositol (3,4,5) trisphosphate and mediates the ... More
Localized suppression of RhoA activity by Tyr31/118-phosphorylated paxillin in cell adhesion and migration.
AuthorsTsubouchi A, Sakakura J, Yagi R, Mazaki Y, Schaefer E, Yano H, Sabe H
JournalJ Cell Biol
PubMed ID12446743
'RhoA activity is transiently inhibited at the initial phase of integrin engagement, when Cdc42- and/or Rac1-mediated membrane spreading and ruffling predominantly occur. Paxillin, an integrin-assembly protein, has four major tyrosine phosphorylation sites, and the phosphorylation of Tyr31 and Tyr118 correlates with cell adhesion and migration. We found that mutation of ... More
Transformation activity of Cdc42 requires a region unique to Rho-related proteins.
AuthorsWu WJ, Lin R, Cerione RA, Manor D
JournalJ Biol Chem
PubMed ID9642217
'The Rho subfamily GTP-binding protein Cdc42 mediates actin cytoskeletal rearrangements and cell cycle progression and is essential for Ras transformation. Expression of a Cdc42 mutant (Cdc42(F28L)) that undergoes spontaneous activation (guanine nucleotide exchange) results in transformation of NIH3T3 fibroblasts. In this report, we show that deletion of residues 120-139 from ... More
Requirement of nuclear factor of activated T-cells in calcineurin-mediated cardiomyocyte hypertrophy.
Authorsvan Rooij E, Doevendans PA, de Theije CC, Babiker FA, Molkentin JD, de Windt LJ
JournalJ Biol Chem
PubMed ID12226086
'The calcium-activated phosphatase calcineurin has been implicated as a critical intracellular signal transducer of cardiomyocyte hypertrophy. Although previous data suggested the nuclear factor of activated T-cells (NFAT) as its sole transcriptional effector, the absolute requirement of NFAT as a mediator of calcineurin signaling has not been examined in the heart. ... More
Molecular cloning and characterization of human trabeculin-alpha, a giant protein defining a new family of actin-binding proteins.
AuthorsSun Y, Zhang J, Kraeft SK, Auclair D, Chang MS, Liu Y, Sutherland R, Salgia R, Griffin JD, Ferland LH, Chen LB
JournalJ Biol Chem
PubMed ID10559237
'We describe the molecular cloning and characterization of a novel giant human cytoplasmic protein, trabeculin-alpha (M(r) = 614,000). Analysis of the deduced amino acid sequence reveals homologies with several putative functional domains, including a pair of alpha-actinin-like actin binding domains; regions of homology to plakins at either end of the ... More
Role of the FYVE finger and the RUN domain for the subcellular localization of Rabip4.
AuthorsMari M, Macia E, Le Marchand-Brustel Y, Cormont M
JournalJ Biol Chem
PubMed ID11509568
'Rabip4 is a Rab4 effector, which possesses a RUN domain, two coiled-coil domains, and a FYVE finger. It is associated with the early endosomes and leads, in concert with Rab4, to the enlargement of endosomes, resulting in the fusion of sorting and recycling endosomes. Our goal was to characterize the ... More
SH2-B is required for growth hormone-induced actin reorganization.
AuthorsHerrington J, Diakonova M, Rui L, Gunter DR, Carter-Su C
JournalJ Biol Chem
PubMed ID10777618
'The Src homology-2 (SH2) domain-containing protein SH2-Bbeta is a substrate of the growth hormone (GH) receptor-associated tyrosine kinase JAK2. Here we tested whether SH2-Bbeta is involved in GH regulation of the actin cytoskeleton. Based on cell fractionation and confocal microscopy, we find SH2-Bbeta present at the plasma membrane and in ... More
Differential control of clustering of the sodium channels Na(v)1.2 and Na(v)1.6 at developing CNS nodes of Ranvier.
AuthorsKaplan MR, Cho MH, Ullian EM, Isom LL, Levinson SR, Barres BA
JournalNeuron
PubMed ID11343648
'Na(v)1.6 is the main sodium channel isoform at adult nodes of Ranvier. Here, we show that Na(v)1.2 and its beta2 subunit, but not Na(v)1.6 or beta1, are clustered in developing central nervous system nodes and that clustering of Na(v)1.2 and Na(v)1.6 is differentially controlled. Oligodendrocyte-conditioned medium is sufficient to induce ... More
Androgen-stimulated DNA synthesis and cytoskeletal changes in fibroblasts by a nontranscriptional receptor action.
AuthorsCastoria G, Lombardi M, Barone MV, Bilancio A, Di Domenico M, Bottero D, Vitale F, Migliaccio A, Auricchio F
JournalJ Cell Biol
PubMed ID12743104
'In NIH3T3 cells, 0.001 nM of the synthetic androgen R1881 induces and stimulates association of androgen receptor (AR) with Src and phosphatidylinositol 3-kinase (Pl3-kinase), respectively, thereby triggering S-phase entry. 10 nM R1881 stimulates Rac activity and membrane ruffling in the absence of the receptor-Src-PI3-kinase complex assembly. The antiandrogen Casodex and ... More
Visualization of the intracellular behavior of HIV in living cells.
'To track the behavior of human immunodeficiency virus (HIV)-1 in the cytoplasm of infected cells, we have tagged virions by incorporation of HIV Vpr fused to the GFP. Observation of the GFP-labeled particles in living cells revealed that they moved in curvilinear paths in the cytoplasm and accumulated in the ... More
Apoptosis in tumour cells photosensitized with Rose Bengal acetate is induced by multiple organelle photodamage.
AuthorsSoldani C, Croce AC, Bottone MG, Fraschini A, Biggiogera M, Bottiroli G, Pellicciari C,
JournalHistochem Cell Biol
PubMed ID17849139
'Rose Bengal (RB) is a very efficient photosensitizer which undergoes inactivation of its photophysical and photochemical properties upon addition of a quencher group-i.e. acetate-to the xanthene rings. The resulting RB acetate (RB-Ac) derivative behaves as a fluorogenic substrate: it easily enters the cells where the native photoactive molecule is restored ... More
Plasma membrane localization of G alpha z requires two signals.
AuthorsMorales J, Fishburn CS, Wilson PT, Bourne HR
JournalMol Biol Cell
PubMed ID9436987
'Three covalent attachments anchor heterotrimeric G proteins to cellular membranes: the alpha subunits are myristoylated and/or palmitoylated, whereas the gamma chain is prenylated. Despite the essential role of these modifications in membrane attachment, it is not clear how they cooperate to specify G protein localization at the plasma membrane, where ... More
Interaction with telencephalin and the amyloid precursor protein predicts a ring structure for presenilins.
AuthorsAnnaert WG, Esselens C, Baert V, Boeve C, Snellings G, Cupers P, Craessaerts K, De Strooper B
JournalNeuron
PubMed ID11719200
'The carboxyl terminus of presenilin 1 and 2 (PS1 and PS2) binds to the neuron-specific cell adhesion molecule telencephalin (TLN) in the brain. PS1 deficiency results in the abnormal accumulation of TLN in a yet unidentified intracellular compartment. The first transmembrane domain and carboxyl terminus of PS1 form a binding ... More
Two-photon fluorescence absorption and emission spectra of dyes relevant for cell imaging.
AuthorsBestvater F, Spiess E, Stobrawa G, Hacker M, Feurer T, Porwol T, Berchner-Pfannschmidt U, Wotzlaw C, Acker H
JournalJ Microsc
PubMed ID12423261
'Two-photon absorption and emission spectra for fluorophores relevant in cell imaging were measured using a 45 fs Ti:sapphire laser, a continuously tuneable optical parametric amplifier for the excitation range 580-1150 nm and an optical multichannel analyser. The measurements included DNA stains, fluorescent dyes coupled to antibodies as well as organelle ... More
Tissue transglutaminase mediates activation of RhoA and MAP kinase pathways during retinoic acid-induced neuronal differentiation of SH-SY5Y cells.
AuthorsSingh US, Pan J, Kao YL, Joshi S, Young KL, Baker KM
JournalJ Biol Chem
PubMed ID12401808
'All-trans-retinoic acid (RA) plays a crucial role in survival and differentiation of neurons. For elucidating signaling mechanisms involved in RA-induced neuronal differentiation, we have selected SH-SY5Y cells, which are an established in vitro cell model for studying RA signaling. Here we report that RA-induced neuronal differentiation of SH-SY5Y cells is ... More
Mast cell tryptase controls paracellular permeability of the intestine. Role of protease-activated receptor 2 and beta-arrestins.
'Tight junctions between intestinal epithelial cells prevent ingress of luminal macromolecules and bacteria and protect against inflammation and infection. During stress and inflammation, mast cells mediate increased mucosal permeability by unknown mechanisms. We hypothesized that mast cell tryptase cleaves protease-activated receptor 2 (PAR2) on colonocytes to increase paracellular permeability. Colonocytes ... More
The role of Frizzled3 and Frizzled6 in neural tube closure and in the planar polarity of inner-ear sensory hair cells.
AuthorsWang Y, Guo N, Nathans J
JournalJ Neurosci
PubMed ID16495441
'In the mouse, Frizzled3 (Fz3) and Frizzled6 (Fz6) have been shown previously to control axonal growth and guidance in the CNS and hair patterning in the skin, respectively. Here, we report that Fz3 and Fz6 redundantly control neural tube closure and the planar orientation of hair bundles on a subset ... More
Espins are multifunctional actin cytoskeletal regulatory proteins in the microvilli of chemosensory and mechanosensory cells.
AuthorsSekerková G, Zheng L, Loomis PA, Changyaleket B, Whitlon DS, Mugnaini E, Bartles JR
JournalJ Neurosci
PubMed ID15190118
'Espins are associated with the parallel actin bundles of hair cell stereocilia and are the target of mutations that cause deafness and vestibular dysfunction in mice and humans. Here, we report that espins are also concentrated in the microvilli of a number of other sensory cells: vomeronasal organ sensory neurons, ... More
PKCepsilon, via its regulatory domain and independently of its catalytic domain, induces neurite-like processes in neuroblastoma cells.
AuthorsZeidman R, Löfgren B, Pâhlman S, Larsson C
JournalJ Cell Biol
PubMed ID10330401
'To investigate the role of protein kinase C (PKC) isoforms in regulation of neurite outgrowth, PKCalpha, betaII, delta, and epsilon fused to enhanced green fluorescent protein (EGFP) were transiently overexpressed in neuroblastoma cells. Overexpression of PKCepsilon-EGFP induced cell processes whereas the other isoforms did not. The effect of PKCepsilon-EGFP was ... More
Alteration in lung particle translocation, macrophage function, and microfilament arrangement in monocrotaline-treated rats.
AuthorsMadl AK, Wilson DW, Segall HJ, Pinkerton KE
JournalToxicol Appl Pharmacol
PubMed ID9875297
'Individuals with preexisting cardiopulmonary disease are thought to be more susceptible to acute episodes of particulate pollution resulting in increased morbidity and mortality. Our study was designed to evaluate particle fate and macrophage function in an animal model of monocrotaline (MCT)-induced pulmonary hypertension. Two weeks following a single MCT injection, ... More
The ligand for osteoprotegerin (OPGL) directly activates mature osteoclasts.
AuthorsBurgess TL, Qian Y, Kaufman S, Ring BD, Van G, Capparelli C, Kelley M, Hsu H, Boyle WJ, Dunstan CR, Hu S, Lacey DL
JournalJ Cell Biol
PubMed ID10225954
'Osteoprotegerin (OPG) and OPG-ligand (OPGL) potently inhibit and stimulate, respectively, osteoclast differentiation (Simonet, W.S., D.L. Lacey, C.R. Dunstan, M. Kelley, M.-S. Chang, R. Luethy, H.Q. Nguyen, S. Wooden, L. Bennett, T. Boone, et al. 1997. Cell. 89:309-319; Lacey, D.L., E. Timms, H.-L. Tan, M.J. Kelley, C.R. Dunstan, T. Burgess, R. ... More
Activation of endogenous thrombin receptors causes clustering and sensitization of epidermal growth factor receptors of swiss 3T3 cells without transactivation.
AuthorsCrouch MF, Davy DA, Willard FS, Berven LA
JournalJ Cell Biol
PubMed ID11266444
'The G protein-coupled thrombin receptor can induce cellular responses in some systems by transactivating the epidermal growth factor (EGF) receptor. This is in part due to the stimulation of ectoproteases that generate EGF receptor ligands. We show here that this cannot account for the stimulation of proliferation or migration by ... More
Rac1 mediates type I collagen-dependent MMP-2 activation. role in cell invasion across collagen barrier.
AuthorsZhuge Y, Xu J
JournalJ Biol Chem
PubMed ID11340084
'Cell migration and proteolysis are two essential processes during tumor invasion and metastasis. Matrix metalloproteinase (MMP)-2 (type IV collagenase; gelatinase A), is implicated in tumor metastasis as well as in primary tumor growth. The Rho family of small GTPases regulates the dynamics of actin cytoskeleton associated with cell motility. In ... More
Fibronectin regulates assembly of actin filaments and focal contacts in cultured cells via the heparin-binding site in repeat III13.
AuthorsBloom L, Ingham KC, Hynes RO
JournalMol Biol Cell
PubMed ID10233160
'Fibroblasts, when plated on the extracellular matrix protein fibronectin (FN), rapidly spread and form an organized actin cytoskeleton. This process is known to involve both the central alpha5beta1 integrin-binding and the C-terminal heparin-binding regions of FN. We found that within the heparin-binding region, the information necessary for inducing organization of ... More
High-throughput investigation of osteoblast response to polymer crystallinity: influence of nanometer-scale roughness on proliferation.
AuthorsWashburn NR, Yamada KM, Simon CG, Kennedy SB, Amis EJ
JournalBiomaterials
PubMed ID14643595
'A high-throughput method for analyzing cellular response to crystallinity in a polymer material is presented. Variations in crystallinity lead to changes in surface roughness on nanometer length scales, and it is shown that cells are exquisitely sensitive to these changes. Gradients of polymer crystallinity were fabricated on films of poly(L-lactic ... More
Regulation of microfilament organization by Kaposi sarcoma-associated herpes virus-cyclin.CDK6 phosphorylation of caldesmon.
AuthorsCuomo ME, Knebel A, Platt G, Morrice N, Cohen P, Mittnacht S
JournalJ Biol Chem
PubMed ID16115893
'Kaposi sarcoma-associated herpes virus (KSHV) encodes a D-like cyclin (K-cyclin) that is thought to contribute to the viral oncogenicity. K-cyclin activates cellular cyclin-dependent kinases (CDK) 4 and 6, generating enzymes with a substrate selectivity deviant from CDK4 and CDK6 activated by D-type cyclins, suggesting different biochemical and biological functions. Here ... More
Regulation of endothelial nitric oxide synthase by the actin cytoskeleton.
AuthorsSu Y, Edwards-Bennett S, Bubb MR, Block ER
JournalAm J Physiol Cell Physiol
PubMed ID12734108
'In the present study, the association of endothelial nitric oxide synthase (eNOS) with the actin cytoskeleton in pulmonary artery endothelial cells (PAEC) was examined. We found that the protein contents of eNOS, actin, and caveolin-1 were significantly higher in the caveolar fraction of plasma membranes than in the noncaveolar fraction ... More
Matrix architecture dictates three-dimensional migration modes of human macrophages: differential involvement of proteases and podosome-like structures.
AuthorsVan Goethem E, Poincloux R, Gauffre F, Maridonneau-Parini I, Le Cabec V,
JournalJ Immunol
PubMed ID20018633
'Tissue infiltration of macrophages, although critical for innate immunity, is also involved in pathologies, such as chronic inflammation and cancer. In vivo, macrophages migrate mostly in a constrained three-dimensional (3D) environment. However, in vitro studies, mainly focused on two dimensions, do not provide meaningful clues about the mechanisms involved in ... More
cGMP-dependent protein kinase inhibits serum-response element-dependent transcription by inhibiting rho activation and functions.
AuthorsGudi T, Chen JC, Casteel DE, Seasholtz TM, Boss GR, Pilz RB,
JournalJ Biol Chem
PubMed ID12119292
'RhoA, in its active GTP-bound form, stimulates transcription through activation of the serum-response factor (SRF). We found that cGMP inhibited serum-induced Rho.GTP loading and transcriptional activation of SRF-dependent reporter genes in smooth muscle and glial cells in a cGMP-dependent protein kinase (G-kinase)-dependent fashion. Serum stimulation of the SRF target gene ... More
Mechanism of filopodia initiation by reorganization of a dendritic network.
AuthorsSvitkina TM, Bulanova EA, Chaga OY, Vignjevic DM, Kojima S, Vasiliev JM, Borisy GG
JournalJ Cell Biol
PubMed ID12566431
'Afilopodium protrudes by elongation of bundled actin filaments in its core. However, the mechanism of filopodia initiation remains unknown. Using live-cell imaging with GFP-tagged proteins and correlative electron microscopy, we performed a kinetic-structural analysis of filopodial initiation in B16F1 melanoma cells. Filopodial bundles arose not by a specific nucleation event, ... More
An inactive pool of GSK-3 at the leading edge of growth cones is implicated in Semaphorin 3A signaling.
AuthorsEickholt BJ, Walsh FS, Doherty P
JournalJ Cell Biol
PubMed ID11956225
'Glycogen synthase kinase (GSK)-3 is a serine/threonine kinase that has been implicated in several aspects in embryonic development and several growth factor signaling cascades. We now report that an inactive phosphorylated pool of the enzyme colocalizes with F-actin in both neuronal and nonneuronal cells. Semaphorin 3A (Sema 3A), a molecule ... More
Twinfilin is required for actin-dependent developmental processes in Drosophila.
AuthorsWahlström G, Vartiainen M, Yamamoto L, Mattila PK, Lappalainen P, Heino TI
JournalJ Cell Biol
PubMed ID11724820
'The actin cytoskeleton is essential for cellular remodeling and many developmental and morphological processes. Twinfilin is a ubiquitous actin monomer-binding protein whose biological function has remained unclear. We discovered and cloned the Drosophila twinfilin homologue, and show that this protein is ubiquitously expressed in different tissues and developmental stages. A ... More
SNIP, a novel SNAP-25-interacting protein implicated in regulated exocytosis.
AuthorsChin LS, Nugent RD, Raynor MC, Vavalle JP, Li L
JournalJ Biol Chem
PubMed ID10625663
'Synaptosome-associated protein of 25 kDa (SNAP-25) is a presynaptic membrane protein that has been clearly implicated in membrane fusion in both developing and mature neurons, although its mechanisms of action are unclear. We have now identified a novel SNAP-25-interacting protein named SNIP. SNIP is a hydrophilic, 145-kDa protein that comprises ... More
Peroxisome proliferator-activated receptor gamma promotes epithelial to mesenchymal transformation by Rho GTPase-dependent activation of ERK1/2.
AuthorsChen L, Necela BM, Su W, Yanagisawa M, Anastasiadis PZ, Fields AP, Thompson EA
JournalJ Biol Chem
PubMed ID16815847
'Peroxisome proliferator-activated receptor gamma (PPARgamma) causes epithelial to mesenchymal transformation (EMT) in intestinal epithelial cells, as evidenced by reorganization of the actin cytoskeleton, acquisition of a polarized, mesenchymal cellular morphology, increased cellular motility, and colony scattering. This response is due to activation of Cdc42, resulting in p21-activated kinase-dependent phosphorylation and ... More
CD28 utilizes Vav-1 to enhance TCR-proximal signaling and NF-AT activation.
AuthorsMichel F, Mangino G, Attal-Bonnefoy G, Tuosto L, Alcover A, Roumier A, Olive D, Acuto O
JournalJ Immunol
PubMed ID11034388
'The mechanism through which CD28 costimulation potentiates TCR-driven gene expression is still not clearly defined. Vav-1, an exchange factor for Rho GTPases thought to regulate, mainly through Rac-1, various signaling components leading to cytokine gene expression, is tyrosine phosphorylated upon CD28 engagement. Here, we provide evidence for a key role ... More
Differential activation of p70 and p85 S6 kinase isoforms during cardiac hypertrophy in the adult mammal.
AuthorsLaser M, Kasi VS, Hamawaki M, Cooper G, Kerr CM, Kuppuswamy D
JournalJ Biol Chem
PubMed ID9733756
'An adult feline right ventricular pressure overload (RVPO) model was used to examine the two S6 kinase (S6K) isoforms, p70(S6K) and p85(S6K), that are involved in translational and transcriptional activation. Biochemical and confocal microscopy analyses at the level of the cardiocyte revealed that p70(S6K) is present predominantly in the cytosol, ... More
YXXL motifs in SH2-Bbeta are phosphorylated by JAK2, JAK1, and platelet-derived growth factor receptor and are required for membrane ruffling.
AuthorsO'Brien KB, Argetsinger LS, Diakonova M, Carter-Su C
JournalJ Biol Chem
PubMed ID12551917
'SH2-Bbeta binds to the activated form of JAK2 and various receptor tyrosine kinases. It is a potent stimulator of JAK2, is required for growth hormone (GH)-induced membrane ruffling, and increases mitogenesis stimulated by platelet-derived growth factor (PDGF) and insulin-like growth factor I. Its domain structure suggests that SH2-Bbeta may act ... More
Fast Ca(2+)-dependent inactivation of the store-operated Ca2+ current (ISOC) in liver cells: a role for calmodulin.
AuthorsLitjens T, Harland ML, Roberts ML, Barritt GJ, Rychkov GY
JournalJ Physiol
PubMed ID15226409
'Store-operated Ca2+ channels (SOCs) provide a major pathway for Ca2+ entry in non-excitable cells. SOCs in immortalized liver cells are highly selective for Ca2+ over other cations and are similar to well-studied Ca2+ release activated Ca2+ (CRAC) channels in haematopoietic cell lines. In the present work, employing H4IIE liver cells, ... More
NO inhibits stretch-induced MAPK activity by cytoskeletal disruption.
AuthorsIngram AJ, James L, Cai L, Thai K, Ly H, Scholey JW
JournalJ Biol Chem
PubMed ID10984494
'Mesangial cells (MC) grown on extracellular matrix protein-coated plates and exposed to cyclic strain/relaxation proliferate and produce extracellular matrix protein, providing an in vitro model of signaling in stretched MC. Intracellular transduction of mechanical strain involves mitogen-activated protein kinases, and we have shown that p42/44 mitogen-activated protein kinase (extracellular signal-regulated ... More
Cellular uptake of the prion protein fragment PrP106-126 in vitro.
AuthorsMcHattie SJ, Brown DR, Bird MM
JournalJ Neurocytol
PubMed ID10590514
'The aetiological agent of prion disease is proposed to be an aberrant isoform of the cell surface glycoprotein known as the prion protein (PrP(c)). This pathological isoform (PrP(Sc)) is abnormally deposited in the extracellular space of diseased CNS. Neurodegeneration in these disease has been shown to be associated with accumulation ... More
RhoA is required for monocyte tail retraction during transendothelial migration.
AuthorsWorthylake RA, Lemoine S, Watson JM, Burridge K
JournalJ Cell Biol
PubMed ID11448997
'Transendothelial migration of monocytes is the process by which monocytes leave the circulatory system and extravasate through the endothelial lining of the blood vessel wall and enter the underlying tissue. Transmigration requires coordination of alterations in cell shape and adhesive properties that are mediated by cytoskeletal dynamics. We have analyzed ... More
Evaluation of cell morphology by video recording and computer-assisted image analysis.
AuthorsBerezin V, Skladchikova G, Bock E
JournalCytometry
PubMed ID9012377
'The aim of this study was to evaluate the effects of various cell culture conditions on cell morphology. Cell morphology was estimated by means of video recording and computer-assisted image analysis. Cell contours from the stored images of either live cells or fixed and stained cells were determined automatically, and ... More
Differential protective activity of alpha A- and alphaB-crystallin in lens epithelial cells.
AuthorsAndley UP, Song Z, Wawrousek EF, Fleming TP, Bassnett S
JournalJ Biol Chem
PubMed ID10967101
'alphaA- and alphaB-crystallins are molecular chaperones expressed at low levels in lens epithelial cells, and their expression increases dramatically during differentiation to lens fibers. However, the functions of alphaA- and alphaB-crystallins in lens epithelial cells have not been studied in detail. In this study, the relative ability of alphaA- and ... More
Individual cell motility studied by time-lapse video recording: influence of experimental conditions.
AuthorsHartmann-Petersen R, Walmod PS, Berezin A, Berezin V, Bock E
JournalCytometry
PubMed ID10918277
'BACKGROUND: Eukaryotic cell motility plays a key role during development, wound healing, and tumour invasion. Computer-assisted image analysis now makes it a realistic task to quantify individual cell motility of a large number of cells. However, the influence of culture conditions before and during measurements has not been investigated systematically. ... More
Diacylglycerol kinase zeta regulates Ras activation by a novel mechanism.
AuthorsTopham MK, Prescott SM
JournalJ Cell Biol
PubMed ID11257115
'Guanine nucleotide exchange factors (GEFs) activate Ras by facilitating its GTP binding. Ras guanyl nucleotide-releasing protein (GRP) was recently identified as a Ras GEF that has a diacylglycerol (DAG)-binding C1 domain. Its exchange factor activity is regulated by local availability of signaling DAG. DAG kinases (DGKs) metabolize DAG by converting ... More
Vav2 is an activator of Cdc42, Rac1, and RhoA.
AuthorsAbe K, Rossman KL, Liu B, Ritola KD, Chiang D, Campbell SL, Burridge K, Der CJ
JournalJ Biol Chem
PubMed ID10744696
'Vav and Vav2 are members of the Dbl family of proteins that act as guanine nucleotide exchange factors (GEFs) for Rho family proteins. Whereas Vav expression is restricted to cells of hematopoietic origin, Vav2 is widely expressed. Although Vav and Vav2 share highly related structural similarities and high sequence identity ... More
The molecular chaperone alphaA-crystallin enhances lens epithelial cell growth and resistance to UVA stress.
AuthorsAndley UP, Song Z, Wawrousek EF, Bassnett S
JournalJ Biol Chem
PubMed ID9813033
'alphaA-Crystallin (alphaA) is a member of the small heat shock protein (sHSP) family and has the ability to prevent denatured proteins from aggregating in vitro. Lens epithelial cells express relatively low levels of alphaA, but in differentiated fiber cells, alphaA is the most abundant soluble protein. The lenses of alphaA-knock-out ... More
Dictyostelium RasG is required for normal motility and cytokinesis, but not growth.
'RasG is the most abundant Ras protein in growing Dictyostelium cells and the closest relative of mammalian Ras proteins. We have generated null mutants in which expression of RasG is completely abolished. Unexpectedly, RasG- cells are able to grow at nearly wild-type rates. However, they exhibit defective cell movement and ... More
Monitoring simultaneous subcellular events in vitro by means of coherent multiprobe fluorescence.
AuthorsPlymale DR, Haskins JR, de la Iglesia FA
JournalNat Med
PubMed ID10086396
Methods and applications of three-color confocal imaging.
AuthorsPaddock SW, Hazen EJ, De Vries PJ
JournalBiotechniques
PubMed ID8994659
A simple method for constructing two- and three-color merged images from grayscale confocal fluorescence images using Adobe Photoshop is outlined. Various computer methods for manipulating and displaying the images are discussed in light of several recent biomedical applications of multi-label confocal microscopy. ... More
Localization of the C3-Like ADP-ribosyltransferase from Staphylococcus aureus during bacterial invasion of mammalian cells.
AuthorsMolinari G, Rohde M, Wilde C, Just I, Aktories K, Chhatwal GS
JournalInfect Immun
PubMed ID16714601
The C3stau2 exoenzyme from Staphylococcus aureus is a C3-like ADP-ribosyltransferase which possesses no specific receptor-binding domain or translocation unit required for entry in target cells where its substrate is located. Here we show that C3stau2 can reach its target after invasion of staphylococci in eukaryotic cells without needing translocation. ... More
Motorized RhoGAP myosin IXb (Myo9b) controls cell shape and motility.
AuthorsHanley PJ, Xu Y, Kronlage M, Grobe K, Schön P, Song J, Sorokin L, Schwab A, Bähler M,
JournalProc Natl Acad Sci U S A
PubMed ID20566876
Directional motility is a fundamental function of immune cells, which are recruited to sites of pathogen invasion or tissue damage by chemoattractant signals. To move, cells need to generate lamellipodial membrane protrusions at the front and retract the trailing end. These elementary events are initiated by Rho-family GTPases, which cycle ... More
Differing modes of tumour cell invasion have distinct requirements for Rho/ROCK signalling and extracellular proteolysis.
AuthorsSahai E, Marshall CJ
JournalNat Cell Biol
PubMed ID12844144
Rho family GTPases regulate the cytoskeleton and cell migration and are frequently overexpressed in tumours. Here, we identify two modes of tumour-cell motility in 3D matrices that involve different usage of Rho signalling. Rho signalling through ROCK promotes a rounded bleb-associated mode of motility that does not require pericellular proteolysis. ... More
Asymmetric localization of frizzled and the establishment of cell polarity in the Drosophila wing.
AuthorsStrutt DI
JournalMol Cell
PubMed ID11239465
The frizzled gene of Drosophila encodes a transmembrane receptor molecule required for cell polarity decisions in the adult cuticle. In the wing, a single trichome is produced by each cell, which normally points distally. In the absence of frizzled function, the trichomes no longer point uniformly distalward. We report that ... More
Signal-regulated activation of serum response factor is mediated by changes in actin dynamics.
AuthorsSotiropoulos A, Gineitis D, Copeland J, Treisman R
JournalCell
PubMed ID10428028
Serum response factor (SRF) regulates transcription of many serum-inducible and muscle-specific genes. Using a functional screen, we identified LIM kinase-1 as a potent activator of SRF. We show that SRF activation by LIM kinase-1 is dependent on its ability to regulate actin treadmilling. LIM kinase activity is not essential for ... More
ATP-mediated glia signaling.
AuthorsCotrina ML, Lin JH, López-García JC, Naus CC, Nedergaard M
JournalJ Neurosci
PubMed ID10751435
Glia calcium signaling has recently been identified as a potent modulator of synaptic transmission. We show here that the spatial expansion of calcium waves is mediated by ATP and subsequent activation of purinergic receptors. Ectopic expression of gap junction proteins, connexins (Cxs), leads to an increase in both ATP release ... More
Paper-supported 3D cell culture for tissue-based bioassays.
AuthorsDerda R, Laromaine A, Mammoto A, Tang SK, Mammoto T, Ingber DE, Whitesides GM,
JournalProc Natl Acad Sci U S A
PubMed ID19846768
Fundamental investigations of human biology, and the development of therapeutics, commonly rely on 2D cell-culture systems that do not accurately recapitulate the structure, function, or physiology of living tissues. Systems for 3D cultures exist but do not replicate the spatial distributions of oxygen, metabolites, and signaling molecules found in tissues. ... More
Mechanical signaling through connective tissue: a mechanism for the therapeutic effect of acupuncture.
AuthorsLangevin HM, Churchill DL, Cipolla MJ
JournalFASEB J
PubMed ID11641255
The mechanism of action of acupuncture remains largely unknown. The reaction to acupuncture needling known as 'de qi', widely viewed as essential to the therapeutic effect of acupuncture, may be a key to understanding its mechanism of action. De qi includes a characteristic needling sensation, perceived by the patient, and ... More
DAG lipase activity is necessary for TRP channel regulation in Drosophila photoreceptors.
AuthorsLeung HT, Tseng-Crank J, Kim E, Mahapatra C, Shino S, Zhou Y, An L, Doerge RW, Pak WL,
JournalNeuron
PubMed ID18579079
In Drosophila, a phospholipase C-mediated signaling cascade links photoexcitation of rhodopsin to the opening of the TRP/TRPL channels. A lipid product of the cascade, diacylglycerol (DAG) and its metabolite(s), polyunsaturated fatty acids (PUFAs), have both been proposed as potential excitatory messengers. A crucial enzyme in the understanding of this process ... More
Filamin B mediates ICAM-1-driven leukocyte transendothelial migration.
AuthorsKanters E, van Rijssel J, Hensbergen PJ, Hondius D, Mul FP, Deelder AM, Sonnenberg A, van Buul JD, Hordijk PL,
JournalJ Biol Chem
PubMed ID18809679
During inflammation, the endothelium mediates rolling and firm adhesion of activated leukocytes. Integrin-mediated adhesion to endothelial ligands of the Ig-superfamily induces intracellular signaling in endothelial cells, which promotes leukocyte transendothelial migration. We identified the actin cross-linking molecule filamin B as a novel binding partner for intracellular adhesion molecule-1 (ICAM-1). Immune ... More
Differential regulation of macropinocytosis by Abi1/Hssh3bp1 isoforms.
BACKGROUND: Macropinocytosis, which is a constitutive cellular process of fluid and macromolecule uptake, is regulated by actin cytoskeleton rearrangements near the plasma membrane. Activation of Rac1, which is proposed to act upstream of the actin polymerization regulatory Wave 2 complex, has been found to correlate with enhanced macropinocytosis. One of ... More
Phosphorylation at the cyclin-dependent kinases site (Thr85) of parathyroid hormone-related protein negatively regulates its nuclear localization.
AuthorsLam MH, House CM, Tiganis T, Mitchelhill KI, Sarcevic B, Cures A, Ramsay R, Kemp BE, Martin TJ, Gillespie MT
JournalJ Biol Chem
PubMed ID10373465
Parathyroid hormone-related protein (PTHrP) is expressed by a wide variety of cells and is considered to act as a secreted factor; however, evidence is accumulating for it to act in an intracrine manner. We have determined that PTHrP localizes to the nucleus at the G1 phase of the cell cycle ... More
Contraction and polymerization cooperate to assemble and close actomyosin rings around Xenopus oocyte wounds.
AuthorsMandato CA, Bement WM
JournalJ Cell Biol
PubMed ID11502762
Xenopus oocytes assemble an array of F-actin and myosin 2 around plasma membrane wounds. We analyzed this process in living oocytes using confocal time-lapse (four-dimensional) microscopy. Closure of wounds requires assembly and contraction of a classic "contractile ring" composed of F-actin and myosin 2. However, this ring works in concert ... More
Transforming growth factor-beta1 mediates epithelial to mesenchymal transdifferentiation through a RhoA-dependent mechanism.
AuthorsBhowmick NA, Ghiassi M, Bakin A, Aakre M, Lundquist CA, Engel ME, Arteaga CL, Moses HL
JournalMol Biol Cell
PubMed ID11160820
Transforming growth factor-beta1 (TGF-beta) can be tumor suppressive, but it can also enhance tumor progression by stimulating the complex process of epithelial-to-mesenchymal transdifferentiaion (EMT). The signaling pathway(s) that regulate EMT in response to TGF-beta are not well understood. We demonstrate the acquisition of a fibroblastoid morphology, increased N-cadherin expression, loss ... More
The short arm of the laminin gamma2 chain plays a pivotal role in the incorporation of laminin 5 into the extracellular matrix and in cell adhesion.
AuthorsGagnoux-Palacios L, Allegra M, Spirito F, Pommeret O, Romero C, Ortonne JP, Meneguzzi G
JournalJ Cell Biol
PubMed ID11352943
Laminin 5 is a basement membrane component that actively promotes adhesion and migration of epithelial cells. Laminin 5 undergoes extracellular proteolysis of the gamma2 chain that removes the NH(2)-terminal short arm of the polypeptide and reduces the size of laminin 5 from 440 to 400 kD. The functional consequence of ... More
Membrane perforations inhibit lysosome fusion by altering pH and calcium in Listeria monocytogenes vacuoles.
AuthorsShaughnessy LM, Hoppe AD, Christensen KA, Swanson JA
JournalCell Microbiol
PubMed ID16611227
Listeria monocytogenes (Lm) evade microbicidal defences inside macrophages by secreting a pore-forming cytolysin listeriolysin O (LLO), which allows Lm to escape vacuoles. LLO also inhibits Lm vacuole fusion with lysosomes, which indicates LLO alters vacuole chemistry prior to release of Lm into cytoplasm. Using fluorescent probes to measure membrane permeability, ... More
A role for Wiskott-Aldrich syndrome protein in T-cell receptor-mediated transcriptional activation independent of actin polymerization.
AuthorsSilvin C, Belisle B, Abo A
JournalJ Biol Chem
PubMed ID11283014
Wiskott-Aldrich syndrome protein (WASP) plays a key role in cytoskeletal rearrangement and transcriptional activation in T-cells. Recent evidence links WASP and related proteins to actin polymerization by the Arp2/3 complex. To study whether the role of WASP in actin polymerization is coupled to T-cell receptor (TCR)-mediated transcriptional activation, we made ... More
Cytoskeletal breakdown and apoptosis elicited by NO donors in cerebellar granule cells require NMDA receptor activation.
AuthorsBonfoco E, Leist M, Zhivotovsky B, Orrenius S, Lipton SA, Nicotera P
JournalJ Neurochem
PubMed ID8931482
We have recently demonstrated that nitric oxide (NO) donors can trigger either apoptosis or necrosis of neurons as a function of the intensity of the exposure. Here, we show that the apoptosis induced by the NO donors S-nitrosocysteine (SNOC) or S-nitroso-N-acetyl-penicillamine (SNAP) in cultured cerebellar granule cells (CGCs) depends on ... More
The NH2 terminus of titin spans the Z-disc: its interaction with a novel 19-kD ligand (T-cap) is required for sarcomeric integrity.
Titin is a giant elastic protein in vertebrate striated muscles with an unprecedented molecular mass of 3-4 megadaltons. Single molecules of titin extend from the Z-line to the M-line. Here, we define the molecular layout of titin within the Z-line; the most NH2-terminal 30 kD of titin is located at ... More
The Listeria monocytogenes hemolysin has an acidic pH optimum to compartmentalize activity and prevent damage to infected host cells.
AuthorsGlomski IJ, Gedde MM, Tsang AW, Swanson JA, Portnoy DA
JournalJ Cell Biol
PubMed ID11901168
Listeria monocytogenes is a facultative intracellular bacterial pathogen that escapes from a phagosome and grows in the host cell cytosol. The pore-forming cholesterol-dependent cytolysin, listeriolysin O (LLO), mediates bacterial escape from vesicles and is approximately 10-fold more active at an acidic than neutral pH. By swapping dissimilar residues from a ... More
mDia-interacting protein acts downstream of Rho-mDia and modifies Src activation and stress fiber formation.
AuthorsSatoh S, Tominaga T
JournalJ Biol Chem
PubMed ID11509578
The formin homology protein mDia is a Rho GTPase effector protein that participates in stress fiber formation, cytokinesis, and transcriptional activation of the serum response factor. Although the function of another effector of Rho, Rho-associated kinase, is well established, relatively little is known about the functional mechanism and the downstream ... More
Two ZBP1 KH domains facilitate beta-actin mRNA localization, granule formation, and cytoskeletal attachment.
Chicken embryo fibroblasts (CEFs) localize beta-actin mRNA to their lamellae, a process important for the maintenance of cell polarity and motility. The localization of beta-actin mRNA requires a cis localization element (zipcode) and involves zipcode binding protein 1 (ZBP1), a protein that specifically binds to the zipcode. Both localize to ... More
Chat, a Cas/HEF1-associated adaptor protein that integrates multiple signaling pathways.
AuthorsSakakibara A, Hattori S
JournalJ Biol Chem
PubMed ID10692442
Cas (Crk-associated substrate) and HEF1 (human enhancer of filamentation) are related adaptor proteins that function in integrin-mediated cell adhesion and antigen receptor signaling pathways. We report here a molecular cloning of Chat (Cas/HEF1-associated signal transducer) that associates with Cas and HEF1. Chat is a 78-kDa signaling molecule with an N-terminal ... More
Characterization of palladin, a novel protein localized to stress fibers and cell adhesions.
AuthorsParast MM, Otey CA
JournalJ Cell Biol
PubMed ID10931874
Here, we describe the identification of a novel phosphoprotein named palladin, which colocalizes with alpha-actinin in the stress fibers, focal adhesions, cell-cell junctions, and embryonic Z-lines. Palladin is expressed as a 90-92-kD doublet in fibroblasts and coimmunoprecipitates in a complex with alpha-actinin in fibroblast lysates. A cDNA encoding palladin was ... More
The fibronectin-binding integrins alpha5beta1 and alphavbeta3 differentially modulate RhoA-GTP loading, organization of cell matrix adhesions, and fibronectin fibrillogenesis.
AuthorsDanen EH, Sonneveld P, Brakebusch C, Fassler R, Sonnenberg A
JournalJ Cell Biol
PubMed ID12486108
We have studied the formation of different types of cell matrix adhesions in cells that bind to fibronectin via either alpha5beta1 or alphavbeta3. In both cases, cell adhesion to fibronectin leads to a rapid decrease in RhoA activity. However, alpha5beta1 but not alphavbeta3 supports high levels of RhoA activity at ... More
Role of actin cortex in the subplasmalemmal transport of secretory granules in PC-12 cells.
AuthorsLang T, Wacker I, Wunderlich I, Rohrbach A, Giese G, Soldati T, Almers W
JournalBiophys J
PubMed ID10827968
In neuroendocrine PC-12 cells, evanescent-field fluorescence microscopy was used to track motions of green fluorescent protein (GFP)-labeled actin or GFP-labeled secretory granules in a thin layer of cytoplasm where cells adhered to glass. The layer contained abundant filamentous actin (F-actin) locally condensed into stress fibers. More than 90% of the ... More
Characterization of the interaction between zyxin and members of the Ena/vasodilator-stimulated phosphoprotein family of proteins.
Zyxin contains a proline-rich N-terminal domain that is similar to the C-terminal domain in the ActA protein of the bacteria, Listeria monocytogenes. We screened the entire amino acid sequence of human zyxin for Mena-interacting peptides and found that, as with ActA, proline-rich sequences were the sole zyxin sequences capable of ... More
The tip of the coiled-coil rod determines the filament formation of smooth muscle and nonmuscle myosin.
AuthorsIkebe M, Komatsu S, Woodhead JL, Mabuchi K, Ikebe R, Saito J, Craig R, Higashihara M
JournalJ Biol Chem
PubMed ID11395487
Myosin II self-assembles to form thick filaments that are attributed to its long coiled-coil tail domain. The present study has determined a region critical for filament formation of vertebrate smooth muscle and nonmuscle myosin II. A monoclonal antibody recognizing the 28 residues from the C-terminal end of the coiled-coil domain ... More
Intracellular trafficking of vitamin E in hepatocytes: the role of tocopherol transfer protein.
AuthorsQian J, Morley S, Wilson K, Nava P, Atkinson J, Manor D
JournalJ Lipid Res
PubMed ID16024914
The term vitamin E denotes a family of tocopherols and tocotrienols, plant lipids that are essential for vertebrate fertility and health. The principal form of vitamin E found in humans, RRR-alpha-tocopherol (TOH), is thought to protect cells by virtue of its ability to quench free radicals, and functions as the ... More
The yeast GRD20 gene is required for protein sorting in the trans-Golgi network/endosomal system and for polarization of the actin cytoskeleton.
AuthorsSpelbrink RG, Nothwehr SF
JournalMol Biol Cell
PubMed ID10588657
The proper localization of resident membrane proteins to the trans-Golgi network (TGN) involves mechanisms for both TGN retention and retrieval from post-TGN compartments. In this study we report identification of a new gene, GRD20, involved in protein sorting in the TGN/endosomal system of Saccharomyces cerevisiae. A strain carrying a transposon ... More
A new family of Cdc42 effector proteins, CEPs, function in fibroblast and epithelial cell shape changes.
AuthorsHirsch DS, Pirone DM, Burbelo PD
JournalJ Biol Chem
PubMed ID11035016
Cdc42, a Rho GTPase, regulates the organization of the actin cytoskeleton by its interaction with several distinct families of downstream effector proteins. Here, we report the identification of four new Cdc42-binding proteins that, along with MSE55, constitute a new family of effector proteins. These molecules, designated CEPs, contain three regions ... More
The p21 Rho-activating toxin cytotoxic necrotizing factor 1 is endocytosed by a clathrin-independent mechanism and enters the cytosol by an acidic-dependent membrane translocation step.
AuthorsContamin S, Galmiche A, Doye A, Flatau G, Benmerah A, Boquet P
JournalMol Biol Cell
PubMed ID10793151
Cytotoxic necrotizing factor 1 (CNF1), a protein produced by pathogenic strains of Escherichia coli, activates the p21 Rho-GTP-binding protein, inducing a profound reorganization of the actin cytoskeleton. CNF1 binds to its cell surface receptor on HEp-2 cells with high affinity (K(d) = 20 pM). In HEp-2 cells the action of ... More
Proteomic analysis of vascular endothelial growth factor-induced endothelial cell differentiation reveals a role for chloride intracellular channel 4 (CLIC4) in tubular morphogenesis.
AuthorsBohman S, Matsumoto T, Suh K, Dimberg A, Jakobsson L, Yuspa S, Claesson-Welsh L
JournalJ Biol Chem
PubMed ID16239224
Formation of new vessels from pre-existing capillaries demands extensive reprogramming of endothelial cells through transcriptional and post-transcriptional events. We show that 120 protein spots in a two-dimensional isoelectric focusing/electrophoretic analysis were affected during vascular endothelial growth factor-A-induced endothelial cell tubular morphogenesis in vitro, as a result of changes in charge ... More
Rabphilin localizes with the cell actin cytoskeleton and stimulates association of granules with F-actin cross-linked by {alpha}-actinin.
In endocrine cell, granules accumulate within an F-actin-rich region below the plasma membrane. The mechanisms involved in this process are largely unknown. Rabphilin is a cytosolic protein that is expressed in neurons and neuroendocrine cells and binds with high affinity to members of the Rab3 family of GTPases localized to ... More
Hyaluronan-CD44 interaction hampers migration of osteoclast-like cells by down-regulating MMP-9.
AuthorsSpessotto P, Rossi FM, Degan M, Di Francia R, Perris R, Colombatti A, Gattei V
JournalJ Cell Biol
PubMed ID12235127
Osteoclast (OC) precursors migrate to putative sites of bone resorption to form functionally active, multinucleated cells. The preOC FLG 29.1 cells, known to be capable of irreversibly differentiating into multinucleated OC-like cells, displayed several features of primary OCs, including expression of specific integrins and the hyaluronan (HA) receptor CD44. OC-like ... More
ROCK and mDia1 antagonize in Rho-dependent Rac activation in Swiss 3T3 fibroblasts.
AuthorsTsuji T, Ishizaki T, Okamoto M, Higashida C, Kimura K, Furuyashiki T, Arakawa Y, Birge RB, Nakamoto T, Hirai H, Narumiya S
JournalJ Cell Biol
PubMed ID12021256
The small GTPase Rho acts on two effectors, ROCK and mDia1, and induces stress fibers and focal adhesions. However, how ROCK and mDia1 individually regulate signals and dynamics of these structures remains unknown. We stimulated serum-starved Swiss 3T3 fibroblasts with LPA and compared the effects of C3 exoenzyme, a Rho ... More
Mammalian Abp1, a signal-responsive F-actin-binding protein, links the actin cytoskeleton to endocytosis via the GTPase dynamin.
AuthorsKessels MM, Engqvist-Goldstein AE, Drubin DG, Qualmann B
JournalJ Cell Biol
PubMed ID11309416
The actin cytoskeleton has been implicated in endocytosis, yet few molecular links to the endocytic machinery have been established. Here we show that the mammalian F-actin-binding protein Abp1 (SH3P7/HIP-55) can functionally link the actin cytoskeleton to dynamin, a GTPase that functions in endocytosis. Abp1 binds directly to dynamin in vitro ... More
Hepatocyte growth factor-induced differential activation of phospholipase cgamma 1 and phosphatidylinositol 3-kinase is regulated by tyrosine phosphatase SHP-1 in astrocytes.
AuthorsMachide M, Kamitori K, Kohsaka S
JournalJ Biol Chem
PubMed ID10896658
Hepatocyte growth factor (HGF) elicits pleiotropic effects on various types of cells through the c-Met receptor tyrosine kinase. However, the mechanisms underlying the diverse responses of cells remain unknown. We show here that HGF promoted chemokinesis of rat primary astrocytes through the activation of phosphatidylinositol 3 (PI3)-kinase without any influence ... More
Calmodulin modulates initiation but not termination of spontaneous Ca2+ sparks in frog skeletal muscle.
AuthorsRodney GG, Schneider MF
JournalBiophys J
PubMed ID12885639
Calmodulin is a ubiquitous Ca(2+) sensing protein that binds to and modulates the sarcoplasmic reticulum Ca(2+) release channel, ryanodine receptor (RYR). Here we assessed the effects of calmodulin on the local Ca(2+) release properties of RYR in permeabilized frog skeletal muscle fibers. Fluorescently labeled recombinant calmodulin in the internal solution ... More
Muscle-specific RING finger-1 interacts with titin to regulate sarcomeric M-line and thick filament structure and may have nuclear functions via its interaction with glucocorticoid modulatory element binding protein-1.
AuthorsMcElhinny AS, Kakinuma K, Sorimachi H, Labeit S, Gregorio CC
JournalJ Cell Biol
PubMed ID11927605
The COOH-terminal A168-170 region of the giant sarcomeric protein titin interacts with muscle-specific RING finger-1 (MURF-1). To investigate the functional significance of this interaction, we expressed green fluorescent protein fusion constructs encoding defined fragments of titin's M-line region and MURF-1 in cardiac myocytes. Upon expression of MURF-1 or its central ... More
Regulation of F-actin and endoplasmic reticulum organization by the trimeric G-protein Gi2 in rat hepatocytes. Implication for the activation of store-operated Ca2+ inflow.
AuthorsWang YJ, Gregory RB, Barritt GJ
JournalJ Biol Chem
PubMed ID10787407
The roles of the heterotrimeric G-protein, G(i2), in regulating the actin cytoskeleton and the activation of store-operated Ca(2+) channels in rat hepatocytes were investigated. Galpha(i2) was principally associated with the plasma membrane and microsomes. Both F-actin and Galpha(i2) were detected by Western blot analysis in a purified plasma membrane preparation, ... More
Interaction of the type IIa Na/Pi cotransporter with PDZ proteins.
AuthorsGisler SM, Stagljar I, Traebert M, Bacic D, Biber J, Murer H
JournalJ Biol Chem
PubMed ID11099500
The type IIa Na(+)-dependent inorganic phosphate (Na/P(i)) cotransporter is localized in the apical membrane of proximal tubular cells and is regulated by an endocytotic pathway. Because molecular processes such as apical sorting, internalization, or subsequent degradation might be assisted by associated proteins, a yeast two-hybrid screen against the C-terminal, cytosolic ... More
Specific contributions of the small GTPases Rho, Rac, and Cdc42 to Dbl transformation.
AuthorsLin R, Cerione RA, Manor D
JournalJ Biol Chem
PubMed ID10438546
Dbl is a representative prototype of a growing family of oncogene products that contain the Dbl homology/pleckstrin homology elements in their primary structures and are associated with a variety of neoplastic pathologies. Members of the Dbl family have been shown to function as physiological activators (guanine nucleotide exchange factors) of ... More
Syndapin isoforms participate in receptor-mediated endocytosis and actin organization.
AuthorsQualmann B, Kelly RB
JournalJ Cell Biol
PubMed ID10704453
Syndapin I (SdpI) interacts with proteins involved in endocytosis and actin dynamics and was therefore proposed to be a molecular link between the machineries for synaptic vesicle recycling and cytoskeletal organization. We here report the identification and characterization of SdpII, a ubiquitously expressed isoform of the brain-specific SdpI. Certain splice ... More
Autocrine activation of the hepatocyte growth factor receptor/met tyrosine kinase induces tumor cell motility by regulating pseudopodial protrusion.
AuthorsVadnais J, Nault G, Daher Z, Amraei M, Dodier Y, Nabi IR, Noël J
JournalJ Biol Chem
PubMed ID12372820
The multiple beta-actin rich pseudopodial protrusions of the invasive variant of Moloney sarcoma virus (MSV)-transformed epithelial MDCK cells (MSV-MDCK-INV) are strongly labeled for phosphotyrosine. Increased tyrosine phosphorylation among a number of proteins was detected in MSV-MDCK-INV cells relative to untransformed and MSV-transformed MDCK cells, especially for the hepatocyte growth factor ... More
The tight junction protein ZO-1 establishes a link between the transmembrane protein occludin and the actin cytoskeleton.
AuthorsFanning AS, Jameson BJ, Jesaitis LA, Anderson JM
JournalJ Biol Chem
PubMed ID9792688
The tight junction protein ZO-1 belongs to a family of multidomain proteins known as the membrane-associated guanylate kinase homologs (MAGUKs). ZO-1 has been demonstrated to interact with the transmembrane protein occludin, a second tight junction-specific MAGUK, ZO-2, and F-actin, although the nature and functional significance of these interactions is poorly ... More
Neural cell adhesion molecule (NCAM) association with PKCbeta2 via betaI spectrin is implicated in NCAM-mediated neurite outgrowth.
AuthorsLeshchyns'ka I, Sytnyk V, Morrow JS, Schachner M
JournalJ Cell Biol
PubMed ID12743109
In hippocampal neurons and transfected CHO cells, neural cell adhesion molecule (NCAM) 120, NCAM140, and NCAM180 form Triton X-100-insoluble complexes with betaI spectrin. Heteromeric spectrin (alphaIbetaI) binds to the intracellular domain of NCAM180, and isolated spectrin subunits bind to both NCAM180 and NCAM140, as does the betaI spectrin fragment encompassing ... More
Sprouty proteins are targeted to membrane ruffles upon growth factor receptor tyrosine kinase activation. Identification of a novel translocation domain.
AuthorsLim J, Wong ES, Ong SH, Yusoff P, Low BC, Guy GR
JournalJ Biol Chem
PubMed ID10887178
Sprouty (Spry) was first identified in a genetic screen in Drosophila to be an antagonist of fibroblast growth factor and epidermal growth factor (EGF) signaling, seemingly by inhibiting the Ras/MAP kinase pathway. Data base searches lead to the identification and cloning of, to date, four mammalian sprouty genes. The primary ... More