Morphology and dynamics of clathrin/GGA1-coated carriers budding from the trans-Golgi network.
AuthorsPuertollano R, van der Wel NN, Greene LE, Eisenberg E, Peters PJ, Bonifacino JS
JournalMol Biol Cell
PubMed ID12686608
'Sorting of transmembrane proteins and their ligands at various compartments of the endocytic and secretory pathways is mediated by selective incorporation into clathrin-coated intermediates. Previous morphological and biochemical studies have shown that these clathrin-coated intermediates consist of spherical vesicles with a diameter of 60-100 nm. Herein, we report the use ... More
Synaptic vesicle proteins and early endosomes in cultured hippocampal neurons: differential effects of Brefeldin A in axon and dendrites.
AuthorsMundigl O, Matteoli M, Daniell L, Thomas-Reetz A, Metcalf A, Jahn R, De Camilli P
JournalJ Cell Biol
PubMed ID8376458
'The pathways of synaptic vesicle (SV) biogenesis and recycling are still poorly understood. We have studied the effects of Brefeldin A (BFA) on the distribution of several SV membrane proteins (synaptophysin, synaptotagmin, synaptobrevin, p29, SV2 and rab3A) and on endosomal markers to investigate the relationship between SVs and the membranes ... More
CLIPR-59, a new trans-Golgi/TGN cytoplasmic linker protein belonging to the CLIP-170 family.
AuthorsPerez F, Pernet-Gallay K, Nizak C, Goodson HV, Kreis TE, Goud B
JournalJ Cell Biol
PubMed ID11854307
'The microtubule cytoskeleton plays a fundamental role in cell organization and membrane traffic in higher eukaryotes. It is well established that molecular motors are involved in membrane-microtubule interactions, but it has also been proposed that nonmotor microtubule-binding (MTB) proteins known as CLIPs (cytoplasmic linker proteins) have basic roles in these ... More
Insect lipoprotein follows a transferrin-like recycling pathway that is mediated by the insect LDL receptor homologue.
AuthorsVan Hoof D, Rodenburg KW, Van der Horst DJ
JournalJ Cell Sci
PubMed ID12356906
'The lipoprotein of insects, high-density lipophorin (HDLp), is homologous to that of mammalian low-density lipoprotein (LDL) with respect to its apolipoprotein structure. Moreover, an endocytic receptor for HDLp has been identified (insect lipophorin receptor, iLR) that is homologus to the LDL receptor. We transfected LDL-receptor-expressing CHO cells with iLR cDNA ... More
Focal exocytosis of VAMP3-containing vesicles at sites of phagosome formation.
AuthorsBajno L, Peng XR, Schreiber AD, Moore HP, Trimble WS, Grinstein S
JournalJ Cell Biol
PubMed ID10791982
'Phagocytosis involves the receptor-mediated extension of plasmalemmal protrusions, called pseudopods, which fuse at their tip to engulf a particle. Actin polymerizes under the nascent phagosome and may propel the protrusion of pseudopods. Alternatively, membrane extension could result from the localized insertion of intracellular membranes into the plasmalemma next to the ... More
Intersectin 2, a new multimodular protein involved in clathrin-mediated endocytosis.
AuthorsPucharcos C, Estivill X, de la Luna S
JournalFEBS Lett
PubMed ID10922467
'Intersectin 1 (ITSN1) is a binding partner of dynamin that has been shown to participate in clathrin-mediated endocytosis. Here we report the characterization of a new human gene, ITSN2, highly similar to ITSN1. Alternative splicing of ITSN2 generates a short isoform with two EH domains, a coiled-coil region and five ... More
Brefeldin A's effects on endosomes, lysosomes, and the TGN suggest a general mechanism for regulating organelle structure and membrane traffic.
'Addition of brefeldin A (BFA) to most cells results in both the formation of extensive, uncoated membrane tubules through which Golgi components redistribute into the ER and the failure to transport molecules out of this mixed ER/Golgi system. In this study we provide evidence that suggests BFA''s effects are not ... More
Selective regulation of endogenous G protein-coupled receptors by arrestins in HEK293 cells.
AuthorsMundell SJ, Benovic JL
JournalJ Biol Chem
PubMed ID10777589
'Arrestins play an important role in regulating desensitization and trafficking of G protein-coupled receptors (GPCRs). However, limited insight into the specificity of arrestin-mediated regulation of GPCRs is currently available. Recently, we used an antisense strategy to reduce arrestin levels in HEK293 cells and characterize the role of arrestins on endogenous ... More
A Rab11-containing rapidly recycling compartment in macrophages that promotes phagocytosis.
AuthorsCox D, Lee DJ, Dale BM, Calafat J, Greenberg S
JournalProc Natl Acad Sci U S A
PubMed ID10639139
'Macrophages are specialized cells of the immune system that exhibit a prodigious capacity for phagocytosis. The ability of macrophages to internalize a substantial proportion of their plasma membrane during phagocytosis indicates that they possess a mechanism for the rapid renewal of plasma membrane. We examined the role of endocytic membrane ... More
Two di-leucine motifs regulate trafficking of mucolipin-1 to lysosomes.
AuthorsVergarajauregui S, Puertollano R
JournalTraffic
PubMed ID16497227
'Mutations in the mucolipin-1 gene have been linked to mucolipidosis type IV, a lysosomal storage disorder characterized by severe neurological and ophthalmologic abnormalities. Mucolipin-1 is a membrane protein containing six putative transmembrane domains with both its N- and C-termini localized facing the cytosol. To gain information on the sorting motifs ... More
Delivery of ligands from sorting endosomes to late endosomes occurs by maturation of sorting endosomes.
AuthorsDunn KW, Maxfield FR
JournalJ Cell Biol
PubMed ID1560027
'After endocytosis, lysosomally targeted ligands pass through a series of endosomal compartments. The endocytic apparatus that accomplishes this passage may be considered to take one of two forms: (a) a system in which lysosomally targeted ligands pass through preexisting, long-lived early sorting endosomes and are then selectively transported to long-lived ... More
Endocytosis of gastrin in cancer cells expressing gastrin/CCK-B receptor.
AuthorsTarasova NI, Wank SA, Hudson EA, Romanov VI, Czerwinski G, Resau JH, Michejda CJ
JournalCell Tissue Res
PubMed ID8995203
'Endocytosis of gastrin was studied in a number of gastrin-receptor-expressing cell lines by confocal laser scanning microscopy (CLSM) with the aid of a biologically active fluorescent derivative, rhodamine green heptagastrin. Rapid clustering (within 4-7 min) and internalization of fluorescent ligand upon binding at room temperature and 37 degrees C were ... More
High-resolution mapping reveals topologically distinct cellular pools of phosphatidylserine.
AuthorsFairn GD, Schieber NL, Ariotti N, Murphy S, Kuerschner L, Webb RI, Grinstein S, Parton RG,
JournalJ Cell Biol
PubMed ID21788369
'Phosphatidylserine (PS) plays a central role in cell signaling and in the biosynthesis of other lipids. To date, however, the subcellular distribution and transmembrane topology of this crucial phospholipid remain ill-defined. We transfected cells with a GFP-tagged C2 domain of lactadherin to detect by light and electron microscopy PS exposed ... More
Regulation and intracellular trafficking pathways of the endothelin receptors.
AuthorsBremnes T, Paasche JD, Mehlum A, Sandberg C, Bremnes B, Attramadal H
JournalJ Biol Chem
PubMed ID10747877
'The effects of endothelin (ET) are mediated via the G protein-coupled receptors ET(A) and ET(B). However, the mechanisms of ET receptor desensitization, internalization, and intracellular trafficking are poorly understood. The aim of the present study was to investigate the molecular mechanisms of ET receptor regulation and to characterize the intracellular ... More
Luminescence quenching by long range electron transfer: a probe of protein clustering and conformation at the cell surface.
AuthorsMatko J, Jenei A, Wei T, Edidin M
JournalCytometry
PubMed ID7736865
'Quenching of luminescence from fluorescent and phosphorescent probes by nitroxide spin labels with a long range electron transfer (LRET) mechanism (44,45) has been tested as a tool to monitor association/clustering and conformational changes of cell surface proteins. The membrane proteins were labeled with monoclonal antibodies or Fab fragments conjugated with ... More
Visualization of G protein-coupled receptor trafficking with the aid of the green fluorescent protein. Endocytosis and recycling of cholecystokinin receptor type A.
AuthorsTarasova NI, Stauber RH, Choi JK, Hudson EA, Czerwinski G, Miller JL, Pavlakis GN, Michejda CJ, Wank SA
JournalJ Biol Chem
PubMed ID9169450
'A chimeric protein consisting of the cholecystokinin receptor type A (CCKAR) and the green fluorescent protein (GFP) was used for studying receptor localization, internalization, and recycling in live cells in real time in four different cell lines. Fusion of the C terminus of the CCKAR to the N terminus of ... More
Dynamin:GTP controls the formation of constricted coated pits, the rate limiting step in clathrin-mediated endocytosis.
AuthorsSever S, Damke H, Schmid SL
JournalJ Cell Biol
PubMed ID10974001
'The GTPase dynamin is essential for receptor-mediated endocytosis, but its function remains controversial. A domain of dynamin, termed the GTPase effector domain (GED), controls dynamin''s high stimulated rates of GTP hydrolysis by functioning as an assembly-dependent GAP. Dyn(K694A) and dyn(R725A) carry point mutations within GED resulting in reduced assembly stimulated ... More
The recycling endosome of Madin-Darby canine kidney cells is a mildly acidic compartment rich in raft components.
AuthorsGagescu R, Demaurex N, Parton RG, Hunziker W, Huber LA, Gruenberg J
JournalMol Biol Cell
PubMed ID10930469
'We present a biochemical and morphological characterization of recycling endosomes containing the transferrin receptor in the epithelial Madin-Darby canine kidney cell line. We find that recycling endosomes are enriched in molecules known to regulate transferrin recycling but lack proteins involved in early endosome membrane dynamics, indicating that recycling endosomes are ... More
Endocytosis of interleukin 2 receptors in human T lymphocytes: distinct intracellular localization and fate of the receptor alpha, beta, and gamma chains.
AuthorsHémar A, Subtil A, Lieb M, Morelon E, Hellio R, Dautry-Varsat A
JournalJ Cell Biol
PubMed ID7698995
'Members of the cytokine receptor family are composed of several noncovalently linked chains with sequence and structure homologies in their extracellular domain. Receptor subfamily members share at least one component: thus the receptors for interleukin (IL) 2 and IL15 have common beta and gamma chains, while those for IL2, 4, ... More
Mechanisms of endothelin receptor subtype-specific targeting to distinct intracellular trafficking pathways.
'We recently reported that the endothelin (ET) receptor subtypes ET(A) and ET(B) are targeted to distinct intracellular destinations upon agonist stimulation (Bremnes, T., Paasche, J. D., Mehlum, A., Sandberg, C., Bremnes, B., and Attramadal, H. (2000) J. Biol. Chem. 275, 17596-17604). The ET(A) receptor was shown to follow the recycling ... More
The TGN38 glycoprotein contains two non-overlapping signals that mediate localization to the trans-Golgi network.
AuthorsPonnambalam S, Rabouille C, Luzio JP, Nilsson T, Warren G
JournalJ Cell Biol
PubMed ID8163544
'The membrane-spanning and cytoplasmic domains of CD4 and CD8 were replaced by those of TGN38. After transient expression in HeLa cells, the location of the hybrid proteins was determined using immunofluorescence and quantitative immuno-electron microscopy, FACS analysis and metabolic labeling. The membrane-spanning domain was found to contain a signal that ... More
Transferrin receptor containing the SDYQRL motif of TGN38 causes a reorganization of the recycling compartment but is not targeted to the TGN.
AuthorsJohnson AO, Ghosh RN, Dunn KW, Garippa R, Park J, Mayor S, Maxfield FR, McGraw TE
JournalJ Cell Biol
PubMed ID8991088
'The SDYQRL motif of the cytoplasmic domain of TGN38 is involved in targeting TGN38 from endosomes to the TGN. To create a system for studying this pathway, we replaced the native transferrin receptor (TR) internalization motif (YTRF) with the SDYQRL TGN-targeting motif. The advantages of using TR as a reporter ... More
VAMP2, but not VAMP3/cellubrevin, mediates insulin-dependent incorporation of GLUT4 into the plasma membrane of L6 myoblasts.
AuthorsRandhawa VK, Bilan PJ, Khayat ZA, Daneman N, Liu Z, Ramlal T, Volchuk A, Peng XR, Coppola T, Regazzi R, Trimble WS, Klip A
JournalMol Biol Cell
PubMed ID10888677
'Like neuronal synaptic vesicles, intracellular GLUT4-containing vesicles must dock and fuse with the plasma membrane, thereby facilitating insulin-regulated glucose uptake into muscle and fat cells. GLUT4 colocalizes in part with the vesicle SNAREs VAMP2 and VAMP3. In this study, we used a single-cell fluorescence-based assay to compare the functional involvement ... More
Functional dissection of COP-I subunits in the biogenesis of multivesicular endosomes.
AuthorsGu F, Aniento F, Parton RG, Gruenberg J
JournalJ Cell Biol
PubMed ID9382865
'In the present paper, we show that transport from early to late endosomes is inhibited at the restrictive temperature in a mutant CHO cell line (ldlF) with a ts-defect in epsilon coatomer protein (epsilonCOP), although internalization and recycling continue. Early endosomes then appear like clusters of thin tubules devoid of ... More
'Dynamin is a 100-kD microtubule-activated GTPase. Recent evidence has revealed a high degree of sequence homology with the product of the Drosophila gene shibire, mutations in which block the recycling of synaptic vesicles and, more generally, the formation of coated and non-coated vesicles at the plasma membrane. We have now ... More
Iterative fractionation of recycling receptors from lysosomally destined ligands in an early sorting endosome.
AuthorsDunn KW, McGraw TE, Maxfield FR
JournalJ Cell Biol
PubMed ID2600137
'To study the fusion and separation of endocytic compartments, we have used digital image analysis to quantify the accumulation of fluorescent ligands in endosomes during continuous endocytosis for periods of 1-20 min. Fluorescently labeled transferrin (Tf) and low density lipoproteins (LDL) were used as markers of recycling receptors and lysosomally ... More
Cellubrevin is a ubiquitous tetanus-toxin substrate homologous to a putative synaptic vesicle fusion protein.
AuthorsMcMahon HT, Ushkaryov YA, Edelmann L, Link E, Binz T, Niemann H, Jahn R, Südhof TC
JournalNature
PubMed ID8332193
'Tetanus toxin inhibits neurotransmitter release by selectively blocking fusion of synaptic vesicles. Recently tetanus toxin was shown to proteolytically degrade synaptobrevin II (also named VAMP-2), a synaptic vesicle-specific protein, in vitro and in nerve terminals. As targets of tetanus toxin, synaptobrevins probably function in the exocytotic fusion of synaptic vesicles. ... More
Regulation of endosome sorting by a specific PP2A isoform.
AuthorsMolloy SS, Thomas L, Kamibayashi C, Mumby MC, Thomas G
JournalJ Cell Biol
PubMed ID9744873
'The regulated sorting of proteins within the trans-Golgi network (TGN)/endosomal system is a key determinant of their biological activity in vivo. For example, the endoprotease furin activates of a wide range of proproteins in multiple compartments within the TGN/endosomal system. Phosphorylation of its cytosolic domain by casein kinase II (CKII) ... More
Fluorescence microscopy techniques for the study of G protein-coupled receptor trafficking.
AuthorsKallal L, Benovic JL
JournalMethods Enzymol
PubMed ID11665588
Vav family GEFs link activated Ephs to endocytosis and axon guidance.
AuthorsCowan CW, Shao YR, Sahin M, Shamah SM, Lin MZ, Greer PL, Gao S, Griffith EC, Brugge JS, Greenberg ME
JournalNeuron
PubMed ID15848800
Ephrin signaling through Eph receptor tyrosine kinases can promote attraction or repulsion of axonal growth cones during development. However, the mechanisms that determine whether Eph signaling promotes attraction or repulsion are not known. We show here that the Rho family GEF Vav2 plays a key role in this process. We ... More
Cholesterol level regulates endosome motility via Rab proteins.
AuthorsChen H, Yang J, Low PS, Cheng JX,
JournalBiophys J
PubMed ID17981910
The role of cholesterol in the regulation of endosome motility was investigated by monitoring the intracellular trafficking of endocytosed folate receptors (FRs) labeled with fluorescent folate conjugates. Real-time fluorescence imaging of HeLa cells transfected with green fluorescent protein-tubulin revealed that FR-containing endosomes migrate along microtubules. Moreover, microinjection with antibodies that ... More
Endocytosis of major histocompatibility complex class I molecules is induced by the HIV-1 Nef protein.
AuthorsSchwartz O, Maréchal V, Le Gall S, Lemonnier F, Heard JM
JournalNat Med
PubMed ID8612235
Like other pathogenic viruses, HIV-1 down-modulates surface expression of major histocompatibility complex class I (MHC-I) molecules in infected cells, thus impairing lysis by cytotoxic T lymphocytes. We have observed that this phenomenon depends on the expression of Nef. nef is an early gene of primate lentiviruses, which is necessary for ... More
Interaction kinetics of tetramethylrhodamine transferrin with human transferrin receptor studied by fluorescence correlation spectroscopy.
AuthorsSchüler J, Frank J, Trier U, Schäfer-Korting M, Saenger W
JournalBiochemistry
PubMed ID10387086
We applied fluorescence correlation spectroscopy (FCS) to characterize the interaction dynamics of fluorescence-labeled transferrin with transferrin receptor (hTfR) associates isolated from human placenta. The dissociation constant for the equilibrium binding of TMR-labeled ferri-transferrin to hTfR in detergent free solution was determined to be 7 +/- 3 nM. Binding curves were ... More
Probing single molecules in single living cells.
AuthorsByassee TA, Chan WC, Nie S
JournalAnal Chem
PubMed ID11101238
Single-molecule detection in single living cells has been achieved by using confocal fluorescence microscopy and externally tagged probe molecules. The intracellular background fluorescence is substantially higher than that in aqueous buffer, but this background is continuous and stable and does not significantly interfere with the measurement of single-molecule photon bursts. ... More
Interactions of GGA3 with the ubiquitin sorting machinery.
AuthorsPuertollano R, Bonifacino JS
JournalNat Cell Biol
PubMed ID15039775
The Golgi-localized, gamma-ear-containing, Arf-binding (GGA) proteins constitute a family of clathrin adaptors that are mainly associated with the trans-Golgi network (TGN) and mediate the sorting of mannose 6-phosphate receptors. This sorting is dependent on the interaction of the VHS domain of the GGAs with acidic-cluster-dileucine signals in the cytosolic tails ... More
Requirement for N-ethylmaleimide-sensitive factor activity at different stages of bacterial invasion and phagocytosis.
AuthorsCoppolino MG, Kong C, Mohtashami M, Schreiber AD, Brumell JH, Finlay BB, Grinstein S, Trimble WS
JournalJ Biol Chem
PubMed ID11092884
Bacterial invasion, like the process of phagocytosis, involves extensive and localized protrusion of the host cell plasma membrane. To examine the molecular mechanisms of the membrane remodeling that accompanies bacterial invasion, soluble NSF attachment protein receptor (SNARE)-mediated membrane traffic was studied in cultured cells during infection by Salmonella typhimurium. A ... More
Overexpression of the myelin proteolipid protein leads to accumulation of cholesterol and proteolipid protein in endosomes/lysosomes: implications for Pelizaeus-Merzbacher disease.
AuthorsSimons M, Kramer EM, Macchi P, Rathke-Hartlieb S, Trotter J, Nave KA, Schulz JB
JournalJ Cell Biol
PubMed ID11956232
Duplications and overexpression of the proteolipid protein (PLP) gene are known to cause the dysmyelinating disorder Pelizaeus-Merzbacher disease (PMD). To understand the cellular response to overexpressed PLP in PMD, we have overexpressed PLP in BHK cells and primary cultures of oligodendrocytes with the Semliki Forest virus expression system. Overexpressed PLP ... More
Adenovirus triggers macropinocytosis and endosomal leakage together with its clathrin-mediated uptake.
Adenovirus type 2 (Ad2) binds the coxsackie B virus Ad receptor and is endocytosed upon activation of the alphav integrin coreceptors. Here, we demonstrate that expression of dominant negative clathrin hub, eps15, or K44A-dynamin (dyn) inhibited Ad2 uptake into epithelial cells, indicating clathrin-dependent viral endocytosis. Surprisingly, Ad strongly stimulated the ... More
Internalization of novel non-viral vector TAT-streptavidin into human cells.
AuthorsRinne J, Albarran B, Jylhävä J, Ihalainen TO, Kankaanpää P, Hytönen VP, Stayton PS, Kulomaa MS, Vihinen-Ranta M
JournalBMC Biotechnol
PubMed ID17199888
BACKGROUND: The cell-penetrating peptide derived from the Human immunodeficiency virus-1 transactivator protein Tat possesses the capacity to promote the effective uptake of various cargo molecules across the plasma membrane in vitro and in vivo. The objective of this study was to characterize the uptake and delivery mechanisms of a novel ... More
Sorting of membrane components from endosomes and subsequent recycling to the cell surface occurs by a bulk flow process.
AuthorsMayor S, Presley JF, Maxfield FR
JournalJ Cell Biol
PubMed ID8509447
A central question in the endocytic process concerns the mechanism for sorting of recycling components (such as transferrin or low density lipoprotein receptors) from lysosomally directed components; membrane-associated molecules including receptors are generally directed towards the recycling pathway while the luminal content of sorting endosomes, consisting of the acid-released ligands, ... More
COOH-terminal signals mediate the trafficking of a peptide processing enzyme in endocrine cells.
AuthorsMilgram SL, Mains RE, Eipper BA
JournalJ Cell Biol
PubMed ID8458870
Peptidylglycine alpha-amidating monooxygenase (PAM) catalyzes the COOH-terminal amidation of bioactive peptides through a two step reaction catalyzed by separate enzymes contained within the PAM precursor. To characterize the trafficking of integral membrane PAM proteins in neuroendocrine cells, we have generated stable AtT-20 cell lines expressing full length and COOH-terminally truncated ... More
Arrestin isoforms dictate differential kinetics of A2B adenosine receptor trafficking.
AuthorsMundell SJ, Matharu AL, Kelly E, Benovic JL
JournalBiochemistry
PubMed ID11041847
Adenosine mediates the activation of adenylyl cyclase via its interaction with specific A(2A) and A(2B) adenosine receptors. Previously, we demonstrated that arrestins are involved in rapid agonist-promoted desensitization of the A(2B) adenosine receptor (A(2B)AR) in HEK293 cells. In the present study, we investigate the role of arrestins in A(2B)AR trafficking. ... More
Phagosomal maturation, acidification, and inhibition of bacterial growth in nonphagocytic cells transfected with FcgammaRIIA receptors.
AuthorsDowney GP, Botelho RJ, Butler JR, Moltyaner Y, Chien P, Schreiber AD, Grinstein S
JournalJ Biol Chem
PubMed ID10497205
Phagocytosis and killing of microbial pathogens by professional phagocytes is an essential component of the innate immune response. Recently, heterologous transfection of individual receptors into nonmyeloid cells has been used successfully to elucidate the early steps that signal phagosome formation. It is unclear, however, whether the vacuoles formed by such ... More
The epithelial sodium-hydrogen antiporter Na+/H+ exchanger 3 accumulates and is functional in recycling endosomes.
AuthorsD'Souza S, Garcia-Cabado A, Yu F, Teter K, Lukacs G, Skorecki K, Moore HP, Orlowski J, Grinstein S
JournalJ Biol Chem
PubMed ID9442041
Na+/H+ exchangers (NHEs) mediate electroneutral exchange of Na+ for H+ and thereby play a central role in pH regulation and Na+ homeostasis. NHE3, the predominant epithelial isoform, is found in apical membranes of renal and intestinal epithelial cells, where it contributes to NaCl (re)absorption. NHE activity has been detected in ... More
Post-Golgi membrane traffic: brefeldin A inhibits export from distal Golgi compartments to the cell surface but not recycling.
AuthorsMiller SG, Carnell L, Moore HH
JournalJ Cell Biol
PubMed ID1629235
Recent studies using the fungal metabolite brefeldin A (BFA) have provided important insights into the dynamics and the organization of the ER/Golgi membrane system. Here we examined the effect of BFA on the functional integrity of the distal part of the secretory pathway, i.e., transport between trans-Golgi cisternae and the ... More
Visualization of the calcitonin receptor-like receptor and its receptor activity-modifying proteins during internalization and recycling.
AuthorsKuwasako K, Shimekake Y, Masuda M, Nakahara K, Yoshida T, Kitaura M, Kitamura K, Eto T, Sakata T
JournalJ Biol Chem
PubMed ID10882736
Expression of the calcitonin receptor-like receptor (CRLR) and its receptor activity modifying proteins (RAMPs) can produce calcitonin gene-related peptide (CGRP) receptors (CRLR/RAMP1) and adrenomedullin (AM) receptors (CRLR/RAMP2 or -3). A chimera of the CRLR and green fluorescent protein (CRLR-GFP) was used to study receptor localization and trafficking in stably transduced ... More
Cellular uptake of exogenous human PDCD5 protein.
AuthorsWang Y, Li D, Fan H, Tian L, Zhong Y, Zhang Y, Yuan L, Jin C, Yin C, Ma D
JournalJ Biol Chem
PubMed ID16754680
PDCD5 (human programmed cell death 5) plays a significant role in apoptotic and paraptotic cell deaths. However, it was found that recombinant PDCD5 added exogenously to culture medium could also enhance programmed cell death triggered by certain stimuli. Here we show that PDCD5 has a remarkable role in intercellular transport ... More
Cellubrevin-targeted fluorescence uncovers heterogeneity in the recycling endosomes.
AuthorsTeter K, Chandy G, Quiñones B, Pereyra K, Machen T, Moore HP
JournalJ Biol Chem
PubMed ID9677389
The pH and trafficking of recycling endosomes have previously been studied using transferrin. We have used another approach, one in which the vesicle transport protein cellubrevin was appended with a luminal IgG epitope to allow targeting of fluorescein-5'-isothiocyanate (FITC)-labeled anti-IgG F(ab) antibodies to the recycling endosomes in living cells. FITC-F(ab) ... More
Perturbation of dynamin II with an amphiphysin SH3 domain increases GLUT4 glucose transporters at the plasma membrane in 3T3-L1 adipocytes. Dynamin II participates in GLUT4 endocytosis.
AuthorsVolchuk A, Narine S, Foster LJ, Grabs D, De Camilli P, Klip A
JournalJ Biol Chem
PubMed ID9525921
The GLUT4 glucose transporter continuously recycles between the cell surface and an endosomal compartment in adipocytes. Insulin decreases the rate of GLUT4 endocytosis in addition to increasing its exocytosis. Endocytosis of the transporter is thought to occur at least in part via the clathrin-mediated endocytic system. The protein dynamin is ... More
Decoding the entry of two novel cell-penetrating peptides in HeLa cells: lipid raft-mediated endocytosis and endosomal escape.
AuthorsFoerg C, Ziegler U, Fernandez-Carneado J, Giralt E, Rennert R, Beck-Sickinger AG, Merkle HP
JournalBiochemistry
PubMed ID15628847
Cellular entry of peptide, protein, and nucleic acid biopharmaceuticals is severely impeded by the cell membrane. Linkage or assembly of such agents and cell-penetrating peptides (CPP) with the ability to cross cellular membranes has opened a new horizon in biomedical research. Nevertheless, the uptake mechanisms of most CPP have been ... More
Role of COPI in phagosome maturation.
AuthorsBotelho RJ, Hackam DJ, Schreiber AD, Grinstein S
JournalJ Biol Chem
PubMed ID10748188
Phagosomes mature by sequentially fusing with endosomes and lysosomes. Vesicle budding is presumed to occur concomitantly, mediating the retrieval of plasmalemmal components and the regulation of phagosomal size. We analyzed whether fission of vesicles from phagosomes requires COPI, a multimeric complex known to be involved in budding from the Golgi ... More
Lipid recycling between the plasma membrane and intracellular compartments: transport and metabolism of fluorescent sphingomyelin analogues in cultured fibroblasts.
AuthorsKoval M, Pagano RE
JournalJ Cell Biol
PubMed ID2738091
We examined the metabolism and intracellular transport of the D-erythro and L-threo stereoisomers of a fluorescent analogue of sphingomyelin, N-(N-[6-[(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino] caproyl])-sphingosylphosphorylcholine (C6-NBD-SM), in Chinese hamster ovary (CHO-K1) fibroblast monolayers. C6-NBD-SM was integrated into the plasma membrane bilayer by transfer of C6-NBD-SM monomers from liposomes to cells at 7 degrees C. ... More
Rab7: a key to lysosome biogenesis.
AuthorsBucci C, Thomsen P, Nicoziani P, McCarthy J, van Deurs B
JournalMol Biol Cell
PubMed ID10679007
The molecular machinery behind lysosome biogenesis and the maintenance of the perinuclear aggregate of late endocytic structures is not well understood. A likely candidate for being part of this machinery is the small GTPase Rab7, but it is unclear whether this protein is associated with lysosomes or plays any role ... More
Lipid stress inhibits endocytosis of melanocortin-4 receptor from modified clathrin-enriched sites and impairs receptor desensitization.