Mutational analysis of the role of hydrophobic residues in the 338-348 helix on actin in actomyosin interactions.
AuthorsMiller CJ, Doyle TC, Bobkova E, Botstein D, Reisler E
JournalBiochemistry
PubMed ID8619986
Yeast actin mutants with alanines replacing I341 and I345 were studied to assess the role of hydrophobic residues in the alpha-helix 338-348 in interactions with myosin. In structural models of the actomyosin complex, this helix on actin was assigned a prominent role in the strong binding of myosin to actin. ... More
Myosin is involved in postmitotic cell spreading.
AuthorsCramer LP, Mitchison TJ
JournalJ Cell Biol
PubMed ID7559774
'We have investigated a role for myosin in postmitotic Potoroo tridactylis kidney (PtK2) cell spreading by inhibitor studies, time-lapse video microscopy, and immunofluorescence. We have also determined the spatial organization and polarity of actin filaments in postmitotic spreading cells. We show that butanedione monoxime (BDM), a known inhibitor of muscle ... More
The sequence of the myosin 50-20K loop affects Myosin's affinity for actin throughout the actin-myosin ATPase cycle and its maximum ATPase activity.
AuthorsMurphy CT, Spudich JA
JournalBiochemistry
PubMed ID10090768
'We are interested in the role that solvent-exposed, proteolytically sensitive surface loops play in myosin function. The 25-50K loop, or loop 1, is near the ATP binding site, while the 50-20K loop (loop 2) is in the actin binding site. Through chimeric studies, we have found that loop 1 affects ... More
Gelsolin displaces phalloidin from actin filaments. A new fluorescence method shows that both Ca2+ and Mg2+ affect the rate at which gelsolin severs F-actin.
AuthorsAllen PG, Janmey PA
JournalJ Biol Chem
PubMed ID7806519
'We describe an assay for measuring both the extent and kinetics of the severing of F-actin, based on the enhanced fluorescence emission of tetramethylrhodamine-phalloidin bound to F-actin. The enhanced fluorescence is lost after exposure to active gelsolin by displacement of the phalloidin from actin during severing. This assay requires small ... More
Actin filament organization in the fish keratocyte lamellipodium.
AuthorsSmall JV, Herzog M, Anderson K
JournalJ Cell Biol
PubMed ID7775574
'From recent studies of locomoting fish keratocytes it was proposed that the dynamic turnover of actin filaments takes place by a nucleation-release mechanism, which predicts the existence of short (less than 0.5 microns) filaments throughout the lamellipodium (Theriot, J. A., and T. J. Mitchison. 1991. Nature (Lond.). 352:126-131). We have ... More
Microscopic analysis of polymerization dynamics with individual actin filaments.
AuthorsFujiwara I, Takahashi S, Tadakuma H, Funatsu T, Ishiwata S
JournalNat Cell Biol
PubMed ID12198494
'The polymerization-depolymerization dynamics of actin is a key process in a variety of cellular functions. Many spectroscopic studies have been performed in solution, but studies on single actin filaments have just begun. Here, we show that the time course of polymerization of individual filaments consists of a polymerization phase and ... More
Interaction of phalloidin with chemically modified actin.
AuthorsMiki M, Barden JA, dos Remedios CG, Phillips L, Hambly BD
JournalEur J Biochem
PubMed ID2952502
'Modification of Tyr-69 with tetranitromethane impairs the polymerizability of actin in accordance with the previous report [Lehrer, S. S. and Elzinga, M. (1972) Fed. Proc. 31, 502]. Phalloidin induces this chemically modified actin to form the same characteristic helical thread-like structure as normal F-actin. The filaments bind myosin heads and ... More
Kinetics of binding of caldesmon to actin.
AuthorsChalovich JM, Chen YD, Dudek R, Luo H
JournalJ Biol Chem
PubMed ID7730374
'The time course of interaction of caldesmon with actin may be monitored by fluorescence changes that occur upon the binding of 12-(N-methyl-N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl))-labeled caldesmon to actin or to acrylodan actin. The concentration dependence of the observed rate of caldesmon-actin binding was analyzed to a first approximation as a single-step reaction using ... More
Antagonistic effects of cofilin, beryllium fluoride complex, and phalloidin on subdomain 2 and nucleotide-binding cleft in F-actin.
AuthorsMuhlrad A, Ringel I, Pavlov D, Peyser YM, Reisler E
JournalBiophys J
PubMed ID16997870
'Cofilin/ADF, beryllium fluoride complex (BeFx), and phalloidin have opposing effects on actin filament structure and dynamics. Cofilin/ADF decreases the stability of F-actin by enhancing disorder in subdomain 2, and by severing and accelerating the depolymerization of the filament. BeFx and phalloidin stabilize the subdomain 2 structure and decrease the critical ... More
Effects of SH1 and SH2 modifications on myosin: similarities and differences.
AuthorsBobkova EA, Bobkov AA, Levitsky DI, Reisler E
JournalBiophys J
PubMed ID9916031
'The properties of myosin modified at the SH2 group (Cys-697) were studied and compared with the previously reported properties of myosin modified at the SH1 group (Cys-707). 4-[N-[(iodoacetoxy)ethyl]-N methylamino]-7-nitrobenz-2-oxa-1, 3-diazole (IANBD) was used for selective modification of the SH2 group on myosin. SH2-labeled heavy meromyosin (SH2-HMM), similar to SH1-labeled HMM ... More
Alphabeta protomers of Na+,K+-ATPase from microsomes of duck salt gland are mostly monomeric: formation of higher oligomers does not modify molecular activity.
AuthorsMartin DW, Marecek J, Scarlata S, Sachs JR
JournalProc Natl Acad Sci U S A
PubMed ID10706623
'The distance that separates alphabeta protomers of the Na(+), K(+)-ATPase in microsomes and in purified membranes prepared from duck nasal salt glands was estimated by measuring fluorescence resonance energy transfer between anthroylouabain bound to a population of alphabeta protomers and either N-[7-nitrobenz-2-oxa-1, 3-diazol-4-yl]-6-aminohexyl ouabain or 5-(and-6)-carboxyfluorescein-6-aminohexyl ouabain bound to the ... More
Comparative investigations on the uptake of phallotoxins, bile acids, bovine lactoperoxidase and horseradish peroxidase into rat hepatocytes in suspension and in cell cultures.
AuthorsPetzinger E, Frimmer M
JournalBiochim Biophys Acta
PubMed ID3120787
'Two alternative uptake mechanisms for phallotoxins by liver cells are debated: carrier-mediated uptake and receptor-mediated endocytosis. We have compared the properties of hepatocellular uptake of the phallotoxins, phalloidin and demethylphalloin, with the uptake of cholate as a substrate for carrier-mediated uptake and compared with iodinated bovine lactoperoxidase or iodinated horseradish ... More
F-actin does not modulate the initial steps of the protein kinase C activation process in living nerve cells.
AuthorsGeeraert V, Dupont JL, Grant NJ, Huvet C, Chasserot-Golaz S, Janoshazi A, Procksch O, de Barry J
JournalExp Cell Res
PubMed ID14499623
'Actin is a major substrate for protein kinase C (PKC) and PKC is considered a modulator of the actin network. In addition in vitro studies (Biochemistry 39 (2000) 271) have suggested that all PKC isoforms bind to actin during the process of activation of the enzyme. To test the physiological ... More
Localization of the phalloidin and nucleotide-binding sites on actin.
AuthorsBarden JA, Miki M, Hambly BD, Dos Remedios CG
JournalEur J Biochem
PubMed ID3830158
'Phalloidin was found to block nucleotide exchange in F-actin, without interfering with nucleotide hydrolysis. This inhibition of nucleotide exchange occurs under conditions in which monomers are able to exchange. The distance separating a fluorescent chromophore attached to phalloidin from the nucleotide on actin was determined using fluorescence resonance energy-transfer spectroscopy. ... More
Stabilization of actin by phalloidin: a differential scanning calorimetric study.
AuthorsLe Bihan T, Gicquaud C
JournalBiochem Biophys Res Commun
PubMed ID1755835
'We have used differential scanning calorimetry to study the effects of phalloidin on F and G actin stability. For F actin, saturating concentrations of phalloidin induced an important shift on the transition temperature, Tm, from 69.5 degrees C to 83.5 degrees C. However, the calorimetric enthalpy remained unchanged. Using lower ... More
The integral membrane protein, ponticulin, acts as a monomer in nucleating actin assembly.
AuthorsChia CP, Shariff A, Savage SA, Luna EJ
JournalJ Cell Biol
PubMed ID8432731
'Ponticulin, an F-actin binding transmembrane glycoprotein in Dictyostelium plasma membranes, was isolated by detergent extraction from cytoskeletons and purified to homogeneity. Ponticulin is an abundant membrane protein, averaging approximately 10(6) copies/cell, with an estimated surface density of approximately 300 per microns2. Ponticulin solubilized in octylglucoside exhibited hydrodynamic properties consistent with ... More
Actin filament annealing in the presence of ATP and phalloidin.
AuthorsKinosian HJ, Selden LA, Estes JE, Gershman LC
JournalBiochemistry
PubMed ID8241122
'The re-formation of actin filaments after fragmentation by sonication in the presence of phalloidin and ATP has been found to follow second-order kinetics. The data are described by a model in which the rate of actin filament annealing is proportional to the square of the number concentration of actin filaments ... More
Inhibition of actin filament depolymerization by the Dictyostelium 30,000-D actin-bundling protein.
AuthorsZigmond SH, Furukawa R, Fechheimer M
JournalJ Cell Biol
PubMed ID1328254
'We have studied the effect of the Dictyostelium discoideum 30,000-D actin-bundling protein on the assembly and disassembly of pyrenyl-labeled actin in vitro. The results indicate that the protein is a potent inhibitor of the rate of actin depolymerization. The inhibition is rapid, dose dependent, and is observed at both ends ... More
Actin's view of actomyosin interface.
AuthorsMiller CJ, Cheung P, White P, Reisler E
JournalBiophys J
PubMed ID7787100
'Actomyosin interactions were examined by using yeast actin mutants with alanines replacing charged amino acid pairs D24/D25, E99/E100, D80/D81, and E83/K84. In the in vitro motility experiments, actin filaments of D24A/D25A or E99A/E100A mutants moved in the presence of 0.7% methylcellulose at the velocities of wild-type actin. Without methylcellulose, these ... More
Cortexillins, major determinants of cell shape and size, are actin-bundling proteins with a parallel coiled-coil tail.
AuthorsFaix J, Steinmetz M, Boves H, Kammerer RA, Lottspeich F, Mintert U, Murphy J, Stock A, Aebi U, Gerisch G
JournalCell
PubMed ID8752217
'Cortexillins I and II of D. discoideum constitute a novel subfamily of proteins with actin-binding sites of the alpha-actinin/spectrin type. The C-terminal halves of these dimeric proteins contain a heptad repeat domain by which the two subunits are joined to form a two-stranded, parallel coiled coil, giving rise to a ... More
Macrophage podosomes assemble at the leading lamella by growth and fragmentation.
AuthorsEvans JG, Correia I, Krasavina O, Watson N, Matsudaira P
JournalJ Cell Biol
PubMed ID12756237
'Podosomes are actin- and fimbrin-containing adhesions at the leading edge of macrophages. In cells transfected with beta-actin-ECFP and L-fimbrin-EYFP, quantitative four-dimensional microscopy of podosome assembly shows that new adhesions arise at the cell periphery by one of two mechanisms; de novo podosome assembly, or fission of a precursor podosome into ... More
Effect of phalloidin on the ATPase activity of striated muscle myofibrils.
AuthorsBukatina AE, Fuchs F
JournalJ Muscle Res Cell Motil
PubMed ID8182107
'Phalloidin was shown to increase the ATPase activity and Ca2+ sensitivity of both bovine cardiac and rabbit psoas myofibrils when assayed in a solution containing 50 mM KCl, 100 mM MOPS (pH 7.0), 2 mM MgCl2, 1 mM ATP, 2 mM EGTA, and varying concentrations of Ca2+ (temperature 21-22 degrees ... More
A simple model for the cooperative stabilisation of actin filaments by phalloidin and jasplakinolide.
AuthorsVisegrády B, Lorinczy D, Hild G, Somogyi B, Nyitrai M
JournalFEBS Lett
PubMed ID15620683
'The stabilisation of magnesium actin filaments by phalloidin and jasplakinolide was studied using the method of differential scanning calorimetry. The results showed that actin could adapt three conformations in the presence of drugs. One conformation was adapted in direct interaction with the drug, while another conformation was identical to that ... More
Binding between maleimidobenzoyl-G-actin and myosin subfragment 1.
AuthorsHozumi T
JournalBiochemistry
PubMed ID1390764
'It is well known that the structural interactions between S-1 moieties of myosin molecules ("cross bridges") and actin molecules in polymerized ("F") form are thought to underlie muscle contraction. It is surmised that such interactions are unitary (actin:S-1 = 1:1), but actual demonstration thereof is handicapped by intrinsic properties of ... More
Vasopressin depolymerizes F-actin in toad bladder epithelial cells.
AuthorsDing GH, Franki N, Condeelis J, Hays RM
JournalAm J Physiol
PubMed ID1899002
'Vasopressin (AVP) induces the rapid fusion of water channel-containing vesicles with the luminal membrane of its target cell. We have carried out a quantitative study of the F-actin content of toad bladder epithelial cells, using the rhodamine phalloidin binding assay. As early as 1 min after AVP stimulation, there is ... More
Induction of the polymerization of actin from the actin:thymosin beta 4 complex by phalloidin, skeletal myosin subfragment 1, chicken intestinal myosin I and free ends of filamentous actin.
AuthorsBallweber E, Hannappel E, Niggemeyer B, Mannherz HG
JournalEur J Biochem
PubMed ID8055911
'Thymosin beta 4 is able to form 1:1 complexes with monomeric (G) actin, thereby stabilizing the intracellular pool of unpolymerized actin. We have searched for factors that are able to induce the polymerization of actin from the actin:thymosin beta 4 complex. Phalloidin, subfragment 1 isolated from rabbit skeletal muscle myosin ... More
Epithelial cell shedding in acute renal injury.
AuthorsRacusen LC
JournalClin Exp Pharmacol Physiol
PubMed ID9590582
'1. To address the postulate that sublethally injured tubular cells may be shed from renal epithelium while still viable, studies were undertaken in vivo in human ''acute tubular necrosis'' and in rabbit models of renal tubular injury. 2. Substantial numbers of viable tubular cells were voided in the urine. When ... More
alpha-Amanitin uptake into hepatocytes. Identification of hepatic membrane transport systems used by amatoxins.
AuthorsKröncke KD, Fricker G, Meier PJ, Gerok W, Wieland T, Kurz G
JournalJ Biol Chem
PubMed ID3745203
'Hepatic transport studies with amatoxins, toxic bicyclic octapeptides from poisonous mushrooms of the genus Amanita were performed, using [(6''-O,1''-N-di[3H]methyl)trp4]-alpha-amanitin and [(6''-O,1''-N-di-methyl)trp4]-[4-[3H]desmethyl)hyi3]-gamma-ama nitin. Uptake into hepatocytes from rat liver was inhibited by taurocholate and antamanide. Photoaffinity labeling studies with isolated hepatocytes and basolateral plasma membranes, using the sodium salt of (7,7-azo-3 ... More
An actin-associated protein present in the microtubule organizing center and the growth cones of PC-12 cells.
AuthorsBearer EL
JournalJ Neurosci
PubMed ID1372044
'The pathfinding ability of the growth cone depends upon the integrity of a dynamic actin filament network. However, although a number of actin-binding proteins have been found in growth cones, it is not known how these proteins come to be concentrated there or how they might interact to produce these ... More
Characterization of the transport of the bicyclic peptide phalloidin by human hepatic transport proteins.
AuthorsFehrenbach T, Cui Y, Faulstich H, Keppler D
JournalNaunyn Schmiedebergs Arch Pharmacol
PubMed ID14530907
'Phalloidin, the major phallotoxin of the mushroom Amanita phalloides, enters hepatocytes by a carrier-mediated mechanism. The molecular identity of the transport proteins mediating phalloidin uptake was so far unknown. Earlier studies in rat liver indicated that phalloidin may share a common mechanism of uptake with organic anions like bile salts. ... More
Role of charged amino acid pairs in subdomain-1 of actin in interactions with myosin.
AuthorsMiller CJ, Reisler E
JournalBiochemistry
PubMed ID7873552
'Yeast actin mutants with alanines replacing charged amino acid pairs D24/D25, E99/E100, D80/D81, and E83/K84 were studied to assess their role in interactions with myosin. In a previous report Dictyostelium actin filaments with residues D24/D25 or E99/E100 replaced with histidines showed complete or partial loss of filament sliding in the ... More
Cytoskeleton of intestinal goblet cells: role of actin filaments in baseline secretion.
AuthorsOliver MG, Specian RD
JournalAm J Physiol
PubMed ID2260668
'Although microtubules appear necessary to maintain mucin granule transport in intestinal goblet cells, the role of microfilaments in mucus secretion is unknown. To determine the functional significance of microfilaments in goblet cell secretion, fluorescent cytochemistry of microfilaments and autoradiographic studies on granule movement were performed on rabbit intestinal goblet cells, ... More
Actin polymerization and intracellular solvent flow in cell surface blebbing.
AuthorsCunningham CC
JournalJ Cell Biol
PubMed ID7790356
'The cortical actin gel of eukaryotic cells is postulated to control cell surface activity. One type of protrusion that may offer clues to this regulation are the spherical aneurysms of the surface membrane known as blebs. Blebs occur normally in cells during spreading and alternate with other protrusions, such as ... More
Binding of phosphate, aluminum fluoride, or beryllium fluoride to F-actin inhibits severing by gelsolin.
AuthorsAllen PG, Laham LE, Way M, Janmey PA
JournalJ Biol Chem
PubMed ID8617730
'Actin exhibits ATPase activity of unknown function that increases when monomers polymerize into filaments. Differences in the kinetics of ATP hydrolysis and the release of the hydrolysis products ADP and inorganic phosphate suggest that phosphate-rich domains exist in newly polymerized filaments. We examined whether the enrichment of phosphate on filamentous ... More
PKC-epsilon regulates basolateral endocytosis in human T84 intestinal epithelia: role of F-actin and MARCKS.
'Protein kinase C (PKC) and the actin cytoskeleton are critical effectors of membrane trafficking in mammalian cells. In polarized epithelia, the role of these factors in endocytic events at either the apical or basolateral membrane is poorly defined. In the present study, phorbol 12-myristate 13-acetate (PMA) and other activators of ... More
A determination of the radial coordinate of Tyr-69 in F-actin using fluorescence energy transfer.
AuthorsMiki M, dos Remedios CG
JournalBiochem Int
PubMed ID2126434
'Fluorescence energy transfer was measured between Tyr-69 residues in an F-actin filament using 5-dimethylaminonaphthalene-1-sulfonyl chloride (DNS-Cl) as a fluorescence energy donor and 4-dimethylaminoazobenzene-4-sulfonyl chloride (DABSYL-Cl) as the acceptor. Both labels are covalently attached to Tyr-69 residues in an F-actin filament. Taking the helical structure of the F-actin filament into consideration, ... More
[The effect of phalloidin on stability of F- and G-actin]
AuthorsVedenkina NS, Kalinichenko LP, Permiakov EA
JournalMol Biol (Mosk)
PubMed ID8552063
'Intrinsic tryptophan fluorescence and fluorescence of a hydrophobic probe bis-ANS were used to study the effect of phalloidin, a bicyclic heptapeptide toxin, on stability of monomeric (G) and polymeric (F) actin. It was found that bis-ANS fluorescence is sensitive to the actin polymerization process. Phalloidin in concentrations from 1 to ... More
Characterization of actin filament severing by actophorin from Acanthamoeba castellanii.
AuthorsMaciver SK, Zot HG, Pollard TD
JournalJ Cell Biol
PubMed ID1757465
'Actophorin is an abundant 15-kD actinbinding protein from Acanthamoeba that is thought to form a nonpolymerizable complex with actin monomers and also to reduce the viscosity of polymerized actin by severing filaments (Cooper et al., 1986. J. Biol. Chem. 261:477-485). Homologous proteins have been identified in sea urchin, chicken, and ... More
The recovery of the polymerizability of Lys-61-labelled actin by the addition of phalloidin. Fluorescence polarization and resonance-energy-transfer measurements.
AuthorsMiki M
JournalEur J Biochem
PubMed ID2951254
'Modification of Lys-61 in actin with fluorescein-5-isothiocyanate (FITC) blocks actin polymerization [Burtnick, L. D. (1984) Biochim. Biophys. Acta 791, 57-62]. FITC-labelled actin recovered its ability to polymerize on addition of phalloidin. The polymers had the same characteristic helical thread-like structure as normal F-actin and the addition of myosin subfragment-1 to ... More
CARMIL is a potent capping protein antagonist: identification of a conserved CARMIL domain that inhibits the activity of capping protein and uncaps capped actin filaments.
AuthorsUruno T, Remmert K, Hammer JA
JournalJ Biol Chem
PubMed ID16434392
'Acanthamoeba CARMIL was previously shown to co-purify with capping protein (CP) and to bind pure CP. Here we show that this interaction inhibits the barbed end-capping activity of CP. Even more strikingly, this interaction drives the uncapping of actin filaments previously capped with CP. These activities are CP-specific; CARMIL does ... More
Effects of cytochalasin and phalloidin on actin.
AuthorsCooper JA
JournalJ Cell Biol
PubMed ID3312229
Taxol binds to polymerized tubulin in vitro.
AuthorsParness J, Horwitz SB
JournalJ Cell Biol
PubMed ID6118377
Poisonous principles of mushrooms of the genus Amanita. Four-carbon amines acting on the central nervous system and cell-destroying cyclic peptides are produced.
AuthorsWieland T
JournalScience
PubMed ID4865716
Influence of phalloidin on both the nucleation and the elongation phase of actin polymerization.
AuthorsWendel H, Dancker P
JournalBiochim Biophys Acta
PubMed ID3651472
Phalloidin, a heptapeptide from the mushroom Amanita phalloides, increased the velocity of actin polymerization, but slightly decreased the velocity of elongation (polymerization onto sonicated F-actin). A plot of log polymerization velocity vs. log actin concentration was less steep in the presence of phalloidin than in its absence, suggesting that the ... More
Phalloidin depletes the mitochondrial Ca2+ compartment of hepatocytes.
AuthorsFaulstich H, Münter K, Mayer D
JournalFEBS Lett
PubMed ID6698211
In 3 h of incubation, primary cultures of rat hepatocytes attach to the substratum and exchange about 2.2 nmol 45Ca2+ per mg protein. In the presence of 1 microM phalloidin, the exchanged amount of 45Ca2+ was found to be decreased by about 30%. Using the uncoupling agent FCCP and the ... More
Interaction of phalloidin with actin.
AuthorsLengsfeld AM, Löw I, Wieland T, Dancker P, Hasselbach W
JournalProc Natl Acad Sci U S A
PubMed ID4368830
Phalloidin, a toxic bicyclic peptide of rapid action from the toadstool, Amanita phalloides, gives rise to polymerization of G-actin to filamentous structures (Ph-actin) in a medium of low ionic strength. Ph-actin closely resembles the microfilaments found in liver membrane fractions (Ph-filaments) after in vivo or in vitro poisoning. Both phalloidin ... More
The phalloidin binding site of F-actin.
AuthorsVandekerckhove J, Deboben A, Nassal M, Wieland T
JournalEMBO J
PubMed ID4065095
Tritium-containing affinity-labelling derivatives of phalloidin, an alkylating iodoacetyl compound (EAL) and a photolabile, carbene generating diazirine (PAL), have been reacted with rabbit muscle actin, the former after protection of thiol groups with N-ethylmaleimide. Labelled peptides generated by tryptic and/or thermolysin digestion were isolated by paper peptide mapping and characterized by ... More
Phallotoxin and actin binding assay by fluorescence enhancement.
AuthorsHuang ZJ, Haugland RP, You WM, Haugland RP
JournalAnal Biochem
PubMed ID1595896
The fluorescence of five fluorophores conjugated to phallotoxins was found to be specifically enhanced upon binding to F-actin in a polymerizing buffer. Rhodamine phalloidin had the greatest fluorescence enhancement of ninefold. The fluorescence titration of rhodamine phalloidin by actin was shown to be consistent with stoichiometric binding. The fluorescence enhancement ... More
A novel structure involved in the formation of liver endothelial cell fenestrae revealed by using the actin inhibitor misakinolide.
AuthorsBraet F, Spector I, De Zanger R, Wisse E
JournalProc Natl Acad Sci U S A
PubMed ID9811852
Hepatic endothelial fenestrae are dynamic structures that act as a sieving barrier to control the extensive exchange of material between the blood and the liver parenchyma. Alterations in the number or diameter of fenestrae by drugs, hormones, toxins, and diseases can produce serious perturbations in liver function. Previous studies have ... More
Position and orientation of phalloidin in F-actin determined by X-ray fiber diffraction analysis.
AuthorsOda T, Namba K, Maéda Y,
JournalBiophys J
PubMed ID15653738
Knowledge of the phalloidin binding position in F-actin and the relevant understanding of the mechanism of F-actin stabilization would help to define the structural characteristics of the F-actin filament. To determine the position of bound phalloidin experimentally, x-ray fiber diffraction data were obtained from well-oriented sols of F-actin and the ... More
Familial hypertrophic cardiomyopathy can be characterized by a specific pattern of orientation fluctuations of actin molecules .
AuthorsBorejdo J, Szczesna-Cordary D, Muthu P, Calander N,
JournalBiochemistry
PubMed ID20509708
A single-point mutation in the gene encoding the ventricular myosin regulatory light chain (RLC) is sufficient to cause familial hypertrophic cardiomyopathy (FHC). Most likely, the underlying cause of this disease is an inefficient energy utilization by the mutated cardiac muscle. We set out to devise a simple method to characterize ... More
Calcium-independent cytoskeleton disassembly induced by BAPTA.
AuthorsSaoudi Y, Rousseau B, Doussière J, Charrasse S, Gauthier-Rouvière C, Morin N, Sautet-Laugier C, Denarier E, Scaïfe R, Mioskowski C, Job D,
JournalEur J Biochem
PubMed ID15265045
In living organisms, Ca2+ signalling is central to cell physiology. The Ca2+ chelator 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid (BAPTA) has been widely used as a probe to test the role of calcium in a large variety of cell functions. Here we show that in most cell types BAPTA has a potent actin and ... More
Modification of the ultrastructure of Entamoeba histolytica after phagocytosis of liposomes loaded with phalloidin.
AuthorsTrudel P, Gicquaud C
JournalEur J Cell Biol
PubMed ID2885196
The specific actin-interacting drug phalloidin has been introduced into the cytoplasm of a highly motile amoeba, Entamoeba histolytica, by a new technique: the phagocytosis of liposomes containing phalloidin. After ingestion of these liposomes, two important modifications of the ultrastructure of the amoeba were observed. First, large nodules of densely packed ... More
Kinetics of actin depolymerization: influence of ions, temperature, age of F-actin, cytochalasin B and phalloidin.
AuthorsWendel H, Dancker P
JournalBiochim Biophys Acta
PubMed ID3756187
Actin, labelled with the fluorescent dye N-(3-pyrenyl)maleimide, was diluted below its critical concentration and depolymerization was followed by measuring the declining fluorescence intensity. The time courses of depolymerization were fitted to a sum of three exponentials. In most cases there was a fast initial phase followed by one or three ... More
Identification of phalloidin uptake systems of rat and human liver.
AuthorsMeier-Abt F, Faulstich H, Hagenbuch B
JournalBiochim Biophys Acta
PubMed ID15238259
To determine whether the liver toxin phalloidin is transported into hepatocytes by one of the known bile salt transporters, we expressed the sodium-dependent Na+/taurocholate cotransporting polypeptide (Ntcp) and several sodium-independent bile salt transporters of the organic anion transporting polypeptide (OATP/SLCO) superfamily in Xenopus laevis oocytes and measured uptake of the ... More
Chemical modification of membrane proteins by brominated taurodehydrocholate in isolated hepatocytes; relationship to the uptake of cholate and of phalloidin and to the sensitivity of hepatocytes to phalloidin.
AuthorsZiegler K, Frimmer M, Möller W, Fasold H
JournalNaunyn Schmiedebergs Arch Pharmacol
PubMed ID6287311
In vitro treatment of isolated rat hepatocytes with brominated taurodehydrocholic acid (BTC) reduced their sensitivity against phalloidin and inhibited the uptake of phalloidin as well as of cholate in an irreversible and concentration dependent manner. BTC was taken up itself by liver cells; this process was inhibited by 4,4'-diisothiocyano 2,2'-stilbene ... More
Actin residue glu(93) is identified as an amino acid affecting myosin binding.
AuthorsRazzaq A, Schmitz S, Veigel C, Molloy JE, Geeves MA, Sparrow JC
JournalJ Biol Chem
PubMed ID10497190
Many mutants have been described that affect the function of the actin encoded by the Drosophila melanogaster indirect flight muscle-specific actin gene, Act88F. We describe the development of procedures for purification of this actin from the other isoforms expressed in the fly as well as in vitro motility, single molecule ... More
Actin filaments regulate voltage-gated ion channels in salamander retinal ganglion cells.
AuthorsSchubert T, Akopian A
JournalNeuroscience
PubMed ID15099672
The regulation of voltage-activated K(+), and Ca(2+) currents by actin filaments was studied in salamander retinal ganglion cells, using the whole-cell patch clamp technique and Ca(2+) imaging. Disruption of F-actin by cytochalasin B or latrunculin B resulted in a reduction of L-type Ca(2+) current by 55+/-4%, and a sustained outward ... More
Interaction of myosin with F-actin: time-dependent changes at the interface are not slow.
AuthorsVan Dijk J, Céline F, Barman T, Chaussepied P
JournalBiophys J
PubMed ID10827986
The kinetics of formation of the actin-myosin complex have been reinvestigated on the minute and second time scales in sedimentation and chemical cross-linking experiments. With the sedimentation method, we found that the binding of the skeletal muscle myosin motor domain (S1) to actin filament always saturates at one S1 bound ... More
A single myosin head can be cross-linked to the N termini of two adjacent actin monomers.
AuthorsBonafé N, Chaussepied P
JournalBiophys J
PubMed ID7787098
Myosin subfragment-1 (S1) can be cross-linked to two actin monomers by 1-ethyl-3-[3-(dimethylamino)-propyl]-carbodiimide only when F-actin is in excess over S1. Electron micrographs of the covalent actin2-S1 complex showed that S1 was cross-linked to two adjacent monomers of the same actin filament. Cross-linking experiments with pre-proteolyzed S1 derivatives in combination with ... More
Regulation of polymorphonuclear leukocyte membrane fluidity: effect of cytoskeletal modification.
AuthorsWiles ME, Dykens JA, Wright CD
JournalJ Leukoc Biol
PubMed ID7915297
We previously demonstrated that the f-actin cytoskeleton modulates oxygen radical production associated with polymorphonuclear leukocyte (PMN) oxidative burst activity. Given the close association of the actin and microtubule cytoskeletons with the plasma membrane and the transmembrane location of the PMN NADPH oxidase, it is likely cytoskeletal change may affect PMN ... More
Localization of actin in the retina of the crayfish Procambarus clarkii.
AuthorsHafner GS, Tokarski TR, Kipp J
JournalJ Neurocytol
PubMed ID1373182
The distribution of actin in the retina of the crayfish was investigated at the LM level using FITC-phalloidin. Fluorescent staining was associated with the main rhabdom and eighth cell rhabdom, the zonula adherens junctions between retinula cells, and the basement membrane of the retina. EM and S1 decoration were used ... More
Structure of the 265-kilodalton complex formed upon EDC cross-linking of subfragment 1 to F-actin.
AuthorsAndreeva AL, Andreev OA, Borejdo J
JournalBiochemistry
PubMed ID8268172
The conventional model of force generation in muscle requires the presence of at least two different contact areas between the myosin head (S1) and the actin filament. It has been found that S1 has two sites available for carbodiimide cross-linking, but it is generally believed that the myosin head can ... More
D3 phosphoinositides and outside-in integrin signaling by glycoprotein IIb-IIIa mediate platelet actin assembly and filopodial extension induced by phorbol 12-myristate 13-acetate.
AuthorsHartwig JH, Kung S, Kovacsovics T, Janmey PA, Cantley LC, Stossel TP, Toker A
JournalJ Biol Chem
PubMed ID8955143
Phorbol 12-myristate 13-acetate (PMA) uncaps a small number of the fast-growing (barbed) ends of actin filaments, thereby eliciting slow actin assembly and extension of filopodia in human blood platelets. These reactions, which also occur in response to immunologic perturbation of the integrin glycoprotein (GP) IIb-IIIa, are sensitive to the phosphoinositide ... More
Effects of jasplakinolide on the kinetics of actin polymerization. An explanation for certain in vivo observations.
AuthorsBubb MR, Spector I, Beyer BB, Fosen KM
JournalJ Biol Chem
PubMed ID10671562
Jasplakinolide paradoxically stabilizes actin filaments in vitro, but in vivo it can disrupt actin filaments and induce polymerization of monomeric actin into amorphous masses. A detailed analysis of the effects of jasplakinolide on the kinetics of actin polymerization suggests a resolution to this paradox. Jasplakinolide markedly enhances the rate of ... More
Drosophila Kelch regulates actin organization via Src64-dependent tyrosine phosphorylation.
AuthorsKelso RJ, Hudson AM, Cooley L
JournalJ Cell Biol
PubMed ID11854310
The Drosophila kelch gene encodes a member of a protein superfamily defined by the presence of kelch repeats. In Drosophila, Kelch is required to maintain actin organization in ovarian ring canals. We set out to study the actin cross-linking activity of Kelch and how Kelch function is regulated. Biochemical studies ... More
Fluorescence quenching studies of fluorescein attached to Lys-61 or Cys-374 in actin: effects of polymerization, myosin subfragment-1 binding, and tropomyosin-troponin binding.
AuthorsMiki M, dos Remedios CG
JournalJ Biochem (Tokyo)
PubMed ID3141394
The resonance energy transfer between fluorescein-5-isothiocyanate (FITC) attached to Lys-61 and Co2+ bound to the high-affinity metal binding site was measured. The distance between FITC and Co2+ on the actin molecule was calculated to be either 1.9 nm, using the absorption spectrum of Co-EDTA or 2.8 nm, using the absorption ... More
Beryllium fluoride and phalloidin restore polymerizability of a mutant yeast actin (V266G,L267G) with severely decreased hydrophobicity in a subdomain 3/4 loop.
AuthorsKuang B, Rubenstein PA
JournalJ Biol Chem
PubMed ID8995427
Holmes proposed that in F-actin, hydrophobic residues in a subdomain 3/4 loop interact with a hydrophobic pocket on the opposing strand resulting in helix stabilization. We have determined how a decreased hydrophobicity of this plug affects yeast actin function. Cells harboring only the V266G, V266D, V266F, L267G, L269D, or L269K ... More
Filamin A, the Arp2/3 complex, and the morphology and function of cortical actin filaments in human melanoma cells.
The Arp2/3 complex and filamin A (FLNa) branch actin filaments. To define the role of these actin-binding proteins in cellular actin architecture, we compared the morphology of FLNa-deficient human melanoma (M2) cells and three stable derivatives of these cells expressing normal FLNa concentrations. All the cell lines contain similar amounts ... More
Evidence for endothelin involvement in the pulmonary vasoconstrictor response to systemic hypoxia in the isolated rat lung.
AuthorsSmith RM, Brown TJ, Roach AG, Williams KI, Woodward B
JournalJ Pharmacol Exp Ther
PubMed ID9353353
We investigated the effect of systemic hypoxia (Krebs-Henseleit solution gassed with 5% CO2/95% N2) on an isolated, perfused rat lung. Hypoxia resulted in a slowly developing sustained increase in pulmonary perfusion pressure (PPP) accompanied by an increase in lung weight (LW). The endothelin (ET) receptor antagonists BQ123 (3 and 10 ... More
Cytoskeletal F-actin patterns quantitated with fluorescein isothiocyanate-phalloidin in normal and transformed cells.
AuthorsVerderame M, Alcorta D, Egnor M, Smith K, Pollack R
JournalProc Natl Acad Sci U S A
PubMed ID6256751
Actin in cultured fibroblasts is organized into a complex set of fibers. Patterns of organization visualized with antibody to actin are similar but not identical to those visualized with fluorescein isothiocyanate-phalloidin (Fl-phalloidin), a chemical that binds to F-actin polymer with a dissociation constant of 2.7 X 10(-7) M [Wulf, E., ... More
Moesin, ezrin, and p205 are actin-binding proteins associated with neutrophil plasma membranes.
AuthorsPestonjamasp K, Amieva MR, Strassel CP, Nauseef WM, Furthmayr H, Luna EJ
JournalMol Biol Cell
PubMed ID7612961
Actin-binding proteins in bovine neutrophil plasma membranes were identified using blot overlays with 125I-labeled F-actin. Along with surface-biotinylated proteins, membranes were enriched in major actin-binding polypeptides of 78, 81, and 205 kDa. Binding was specific for F-actin because G-actin did not bind. Further, unlabeled F-actin blocked the binding of 125I-labeled ... More
Rho controls cortical F-actin disassembly in addition to, but independently of, secretion in mast cells.
AuthorsSullivan R, Price LS, Koffer A
JournalJ Biol Chem
PubMed ID10608885
Localized disassembly of cortical F-actin has long been considered necessary for facilitation of exocytosis. Exposure of permeabilized mast cells to calcium/ATP induces cortical F-actin disassembly (calmodulin-dependent) and secretion (calmodulin-independent). The delay in the onset of secretion is characteristic for the calcium/ATP response and is abolished by GTP. Here we report ... More
Interaction between vacuolar H(+)-ATPase and microfilaments during osteoclast activation.
AuthorsLee BS, Gluck SL, Holliday LS
JournalJ Biol Chem
PubMed ID10506172
Vacuolar H(+)-ATPases (V-ATPases) are multisubunit enzymes that acidify compartments of the vacuolar system of all eukaryotic cells. In osteoclasts, the cells that degrade bone, V-ATPases, are recruited from intracellular membrane compartments to the ruffled membrane, a specialized domain of the plasma membrane, where they are maintained at high densities, serving ... More
Calcium dependence of phalloidin-induced liver cell death.
AuthorsKane AB, Young EE, Schanne FA, Farber JL
JournalProc Natl Acad Sci U S A
PubMed ID6767245
The role of Ca2+ in toxic liver cell death was studied with primary cultures of adult rat hepatocytes. Within 1 hr of exposure to phalloidin, a bicyclic heptapeptide isolated from the mushroom Amanita pahlloides, at 50 micrograms/ml, 60--70% of the cells were dead (trypan blue stainable). There was no loss ... More
Specific cross-linking of the SH1 thiol of skeletal myosin subfragment 1 to F-actin and G-actin.
AuthorsBettache N, Bertrand R, Kassab R
JournalBiochemistry
PubMed ID1731896
Recently, we reported that (maleimidobenzoyl)-G-actin (MBS-G-actin), which was resistant to the salt and myosin subfragment 1 (S-1) induced polymerizations, reacts reversibly and covalently in solution with the S-1 heavy chain at or near the strong F-actin binding region [Bettache, N., Bertrand, R., & Kassab, R. (1989) Proc. Natl. Acad. Sci. ... 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
Quantitation of actin polymerization in two human fibroblast sub-types responding to mechanical stretching.
AuthorsPender N, McCulloch CA
JournalJ Cell Sci
PubMed ID1795024
To study early reorganization of the cytoskeleton in response to physical forces, human gingival and periodontal ligament fibroblasts were cultured on flexible plastic substrata and stretched by mechanical deformation of the substratum. F-actin was measured by quantitative spectrofluorimetry of FITC-phalloidin-stained cells. Fluorescence due to FITC-phalloidin was reduced stoichiometrically by co-incubation ... More
Interaction of Lys-61 labeled actin with myosin subfragment-1 and the regulatory proteins.
AuthorsMiki M
JournalJ Biochem (Tokyo)
PubMed ID2532648
Actin modified at Lys-61 with fluorescein 5-isothiocyanate (FITC) recovers the ability to polymerize following the binding of phalloidin. The resulting polymer (FITC-P-actin) activates the S1-Mg2+-ATPase activity to the same extent as non-labeled F-actin. However, in the absence of phalloidin, FITC-actin (0.5 mg/ml) neither polymerized nor activated the S1-Mg2+-ATPase activity effectively ... More
Anillin, a contractile ring protein that cycles from the nucleus to the cell cortex.
AuthorsField CM, Alberts BM
JournalJ Cell Biol
PubMed ID7559773
We report the cDNA sequence and localization of a protein first identified by actin filament chromatography of Drosophila embryo extracts as ABP8 (Miller, K. G., C. M. Field, and B. M. Alberts. 1989. J. Cell Biol. 109:2963-2975). The cDNA encodes a 1201-amino acid protein which we name anillin. Anillin migrates ... More
Actin polymerization induced by GTP gamma S in permeabilized neutrophils is induced and maintained by free barbed ends.
AuthorsTardif M, Huang S, Redmond T, Safer D, Pring M, Zigmond SH
JournalJ Biol Chem
PubMed ID7499294
To address the mechanisms through which agonists stimulate actin polymerization, we examined the roles of monomer sequestering proteins and free barbed ends on actin polymerization induced by guanosine 5'-3-O-(thio)triphosphate (GTP gamma S) in neutrophils permeabilized with streptolysin O. Addition of profilin (without GTP gamma S) caused a net decrease in ... More
Determination of the radial coordinate of Cys-374 in F-actin using fluorescence resonance energy transfer spectroscopy: effect of phalloidin on polymer assembly.
AuthorsMoens PD, Yee DJ, dos Remedios CG
JournalBiochemistry
PubMed ID7947715
In helically symmetric protein assemblies, fluorescence resonance energy transfer (FRET) spectroscopy can be used to determine the radial coordinates of fluorescent probes attached to specific amino acid side chains. This is done by separately labeling monomers with donor and acceptor probes, mixing them in different proportions, allowing the mixtures to ... More
Inhibitory region of troponin I: Ca(2+)-dependent structural and environmental changes in the troponin-tropomyosin complex and in reconstituted thin filaments.
AuthorsKobayashi T, Kobayashi M, Gryczynski Z, Lakowicz JR, Collins JH
JournalBiochemistry
PubMed ID10625482
In muscle thin filaments, the inhibitory region (residues 96-117) of troponin I (TnI) is thought to interact with troponin C (TnC) in the presence of Ca(2+) and with actin in the absence of Ca(2+). To better understand these interactions, we prepared mutant TnIs which contained a single Cys-96 or Cys-117 ... More
A correlative analysis of actin filament assembly, structure, and dynamics.
AuthorsSteinmetz MO, Goldie KN, Aebi U
JournalJ Cell Biol
PubMed ID9245786
The effect of the type of metal ion (i.e., Ca2+, Mg2+, or none) bound to the high-affinity divalent cation binding site (HAS) of actin on filament assembly, structure, and dynamics was investigated in the absence and presence of the mushroom toxin phalloidin. In agreement with earlier reports, we found the ... More
Fluorescence probing of yeast actin subdomain 3/4 hydrophobic loop 262-274. Actin-actin and actin-myosin interactions in actin filaments.
AuthorsFeng L, Kim E, Lee WL, Miller CJ, Kuang B, Reisler E, Rubenstein PA
JournalJ Biol Chem
PubMed ID9201989
Residues 262-274 form a loop between subdomains 3 and 4 of actin. This loop may play an important role in actin filament formation and stabilization. To assess directly the behavior of this loop, we mutated Ser265 of yeast actin to cysteine (S265C) and created another mutant (S265C/C374A) by changing Cys374 ... More
Calcium-triggered movement of regulated actin in vitro. A fluorescence microscopy study.
AuthorsHonda H, Asakura S
JournalJ Mol Biol
PubMed ID2522555
We previously reported setting up an in vitro system for the observation of actin filament sliding along myosin filaments. The system involved a minute amount of fluorescently labelled F-actin, and its movement was monitored by fluorescence microscopy. Here, we report observations of the Ca2+-dependent movement of F-actin complex with tropomyosin ... More
Induction of actin polymerization in permeabilized neutrophils. Role of ATP.
AuthorsRedmond T, Tardif M, Zigmond SH
JournalJ Biol Chem
PubMed ID8063808
We have used streptolysin-O (SO)-permeabilized neutrophils to investigate the signal transduction pathway through which chemoattractants induce actin polymerization. Chemoattractants stimulate phosphorylation of various proteins and lipids but whether these phosphorylations are required for actin polymerization is not known. Addition of guanosine 5'-3-O-(thio)triphosphate (GTP gamma S) to SO-permeabilized neutrophils induced a ... More
Visualization of melanosome dynamics within wild-type and dilute melanocytes suggests a paradigm for myosin V function In vivo.
AuthorsWu X, Bowers B, Rao K, Wei Q, Hammer JA
JournalJ Cell Biol
PubMed ID9864363
Unlike wild-type mouse melanocytes, where melanosomes are concentrated in dendrites and dendritic tips, melanosomes in dilute (myosin Va-) melanocytes are concentrated in the cell center. Here we sought to define the role that myosin Va plays in melanosome transport and distribution. Actin filaments that comprise a cortical shell running the ... More
Actin dynamics at the living cell submembrane imaged by total internal reflection fluorescence photobleaching.
AuthorsSund SE, Axelrod D
JournalBiophys J
PubMed ID10969025
Although reversible chemistry is crucial to dynamical processes in living cells, relatively little is known about relevant chemical kinetic rates in vivo. Total internal reflection/fluorescence recovery after photobleaching (TIR/FRAP), an established technique previously demonstrated to measure reversible biomolecular kinetic rates at surfaces in vitro, is extended here to measure reversible ... More
Alterations in human proximal tubule cell attachment in response to hypoxia: role of microfilaments.
AuthorsRacusen LC
JournalJ Lab Clin Med
PubMed ID8133146
Detachment of viable renal proximal tubular cells is seen in clinical and experimental acute tubular necrosis and may contribute to the acute renal dysfunction seen in acute tubular necrosis. Mechanisms of detachment of tubular cells are unknown but must involve changes in tubular cell adhesion. To begin to define mechanisms ... More
Coordinated regulation of platelet actin filament barbed ends by gelsolin and capping protein.
Exposure of cryptic actin filament fast growing ends (barbed ends) initiates actin polymerization in stimulated human and mouse platelets. Gelsolin amplifies platelet actin assembly by severing F-actin and increasing the number of barbed ends. Actin filaments in stimulated platelets from transgenic gelsolin-null mice elongate their actin without severing. F-actin barbed ... More
Flexibility of actin filaments derived from thermal fluctuations. Effect of bound nucleotide, phalloidin, and muscle regulatory proteins.
Single actin filaments undergoing brownian movement in two dimensions were observed at 20 degrees C in fluorescence optical video microscopy. The persistence length (Lp) was derived from the analysis of either the cosine correlation function or the average transverse fluctuations of a series of recorded shapes of filaments assembled from ... More
Role of actin-filament disassembly in lamellipodium protrusion in motile cells revealed using the drug jasplakinolide.
AuthorsCramer LP
JournalCurr Biol
PubMed ID10531004
BACKGROUND: In motile cells, protrusion of the lamellipodium (a type of cell margin) requires assembly of actin monomers into actin filaments at the tip of the lamellipodium. The importance of actin-filament disassembly in this process is less well understood, and is assessed here using the actin drug jasplakinolide, which has ... More
A reversible conformational transition in muscle actin is caused by nucleotide exchange and uncovers cysteine in position 10.
AuthorsDrewes G, Faulstich H
JournalJ Biol Chem
PubMed ID2005093
ATP-G-actin in the absence of excess ATP and divalent metal ions was treated with ADP in amounts large enough to ensure complete formation of ADP-G-actin. Under these conditions the monomer undergoes a very slow structural transition as seen by the exposure of 2.0 +/- 0.2 thiol groups per actin molecule. ... More
Regulation of the actin-activated ATPase and in vitro motility activities of monomeric and filamentous Acanthamoeba myosin II.
AuthorsGanguly C, Baines IC, Korn ED, Sellers J
JournalJ Biol Chem
PubMed ID1400404
The actin-activated Mg(2+)-ATPase activity of filamentous Acanthamoeba myosin II is inhibited by phosphorylation of 3 serine residues at the tip of the tail of each heavy chain. From previous studies, it had been concluded that the activity of each molecule in the filament was regulated by the global state of ... More
Growth inhibition and changes in morphology and actin distribution in Acetabularia acetabulum by phalloidin and phalloidin derivatives.
AuthorsSawitzky H, Hanfstingl U, Faulstich H
JournalProtoplasma
PubMed ID12664285
Effects on morphology and microfilament structure caused by phalloidin, phallacidin, and some semisynthetic phalloidin derivatives were studied in vegetative cells of the green alga Acetabularia acetabulum (L.) Silva. All phalloidin derivatives (except for phalloidin itself) caused growth stop of the alga after 1 day and (except for the fluorescein-labeled phalloidin) ... More
Kinetics of structural changes of reconstituted skeletal muscle thin filaments observed by fluorescence resonance energy transfer.
AuthorsMiki M, Iio T
JournalJ Biol Chem
PubMed ID8463245
Fluorescence resonance energy transfer was measured between probes attached to Troponin-I and actin in the reconstituted skeletal muscle thin filament. Cys-133 on TnI was labeled with 4-acetamido-4'-maleimidylstilbene-2,2'-disulfonic acid, and Lys-61 on actin was labeled with fluorescein 5-isothiocyanate. A large difference in the efficiency of resonance energy transfer was observed between ... More
Cytoskeleton as a target for injury in damaged intestinal epithelium.
AuthorsMiller TA, Smith GS, Banan A, Kokoska ER
JournalMicrosc Res Tech
PubMed ID11054865
This report summarizes the findings of a series of studies undertaken to discern the role of the cytoskeleton in intestinal injury and defense. Two established cell lines were used for these studies. IEC-6 cells (a rat intestinal cell line) were incubated in Eagle's minimal essential medium with and without 16, ... More
Analysis of CD44-containing lipid rafts: Recruitment of annexin II and stabilization by the actin cytoskeleton.
AuthorsOliferenko S, Paiha K, Harder T, Gerke V, Schwärzler C, Schwarz H, Beug H, Günthert U, Huber LA
JournalJ Cell Biol
PubMed ID10459018
CD44, the major cell surface receptor for hyaluronic acid (HA), was shown to localize to detergent-resistant cholesterol-rich microdomains, called lipid rafts, in fibroblasts and blood cells. Here, we have investigated the molecular environment of CD44 within the plane of the basolateral membrane of polarized mammary epithelial cells. We show that ... More