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Tebaldi G, Pritchard SM, Nicola AV. Herpes Simplex Virus Entry by a Nonconventional Endocytic Pathway. J Virol 2020; 94:e01910-20. [PMID: 33028710 PMCID: PMC7925185 DOI: 10.1128/jvi.01910-20] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Accepted: 09/28/2020] [Indexed: 12/24/2022] Open
Abstract
Herpes simplex virus 1 (HSV-1) causes significant morbidity and mortality in humans worldwide. HSV-1 enters epithelial cells via an endocytosis mechanism that is low-pH dependent. However, the precise intracellular pathway has not been identified, including the compartment where fusion occurs. In this study, we utilized a combination of molecular and pharmacological approaches to better characterize HSV entry by endocytosis. HSV-1 entry was unaltered in both cells treated with small interfering RNA (siRNA) to Rab5 or Rab7 and cells expressing dominant negative forms of these GTPases, suggesting entry is independent of the conventional endo-lysosomal network. The fungal metabolite brefeldin A (BFA) and the quinoline compound Golgicide A (GCA) inhibited HSV-1 entry via beta-galactosidase reporter assay and impaired incoming virus transport to the nuclear periphery, suggesting a role for trans-Golgi network (TGN) functions and retrograde transport in HSV entry. Silencing of Rab9 or Rab11 GTPases, which are involved in the retrograde transport pathway, resulted in only a slight reduction in HSV infection. Together, these results suggest that HSV enters host cells by an intracellular route independent of the lysosome-terminal endocytic pathway.IMPORTANCE Herpes simplex virus 1 (HSV-1), the prototype alphaherpesvirus, is ubiquitous in the human population and causes lifelong infection that can be fatal in neonatal and immunocompromised individuals. HSV enters many cell types by endocytosis, including epithelial cells, the site of primary infection in the host. The intracellular itinerary for HSV entry remains unclear. We probed the potential involvement of several Rab GTPases in HSV-1 entry and suggest that endocytic entry of HSV-1 is independent of the canonical lysosome-terminal pathway. A nontraditional endocytic route may be employed, such as one that intersects with the trans-Golgi network (TGN). These results may lead to novel targets for intervention.
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Affiliation(s)
- Giulia Tebaldi
- Department of Veterinary Microbiology and Pathology, College of Veterinary Medicine, Washington State University, Pullman, Washington, USA
| | - Suzanne M Pritchard
- Department of Veterinary Microbiology and Pathology, College of Veterinary Medicine, Washington State University, Pullman, Washington, USA
| | - Anthony V Nicola
- Department of Veterinary Microbiology and Pathology, College of Veterinary Medicine, Washington State University, Pullman, Washington, USA
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Vogel GF, Janecke AR, Krainer IM, Gutleben K, Witting B, Mitton SG, Mansour S, Ballauff A, Roland JT, Engevik AC, Cutz E, Müller T, Goldenring JR, Huber LA, Hess MW. Abnormal Rab11-Rab8-vesicles cluster in enterocytes of patients with microvillus inclusion disease. Traffic 2017; 18:453-464. [PMID: 28407399 DOI: 10.1111/tra.12486] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Revised: 04/05/2017] [Accepted: 04/05/2017] [Indexed: 12/14/2022]
Abstract
Microvillus inclusion disease (MVID) is a congenital enteropathy characterized by accumulation of vesiculo-tubular endomembranes in the subapical cytoplasm of enterocytes, historically termed "secretory granules." However, neither their identity nor pathophysiological significance is well defined. Using immunoelectron microscopy and tomography, we studied biopsies from MVID patients (3× Myosin 5b mutations and 1× Syntaxin3 mutation) and compared them to controls and genome-edited CaCo2 cell models, harboring relevant mutations. Duodenal biopsies from 2 patients with novel Myosin 5b mutations and typical clinical symptoms showed unusual ultrastructural phenotypes: aberrant subapical vesicles and tubules were prominent in the enterocytes, though other histological hallmarks of MVID were almost absent (ectopic intra-/intercellular microvilli, brush border atrophy). We identified these enigmatic vesiculo-tubular organelles as Rab11-Rab8-positive recycling compartments of altered size, shape and location harboring the apical SNARE Syntaxin3, apical transporters sodium-hydrogen exchanger 3 (NHE3) and cystic fibrosis transmembrane conductance regulator. Our data strongly indicate that in MVID disrupted trafficking between cargo vesicles and the apical plasma membrane is the primary cause of a defect of epithelial polarity and subsequent facultative loss of brush border integrity, leading to malabsorption. Furthermore, they support the notion that mislocalization of transporters, such as NHE3 substantially contributes to the reported sodium loss diarrhea.
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Affiliation(s)
- Georg F Vogel
- Division of Histology and Embryology, Medical University of Innsbruck, Innsbruck, Austria.,Division of Cell Biology, Medical University of Innsbruck, Innsbruck, Austria.,Department of Paediatrics I, Medical University of Innsbruck, Innsbruck, Austria
| | - Andreas R Janecke
- Department of Paediatrics I, Medical University of Innsbruck, Innsbruck, Austria
| | - Iris M Krainer
- Division of Cell Biology, Medical University of Innsbruck, Innsbruck, Austria.,Department of Paediatrics I, Medical University of Innsbruck, Innsbruck, Austria
| | - Karin Gutleben
- Division of Histology and Embryology, Medical University of Innsbruck, Innsbruck, Austria
| | - Barbara Witting
- Division of Histology and Embryology, Medical University of Innsbruck, Innsbruck, Austria
| | | | - Sahar Mansour
- Human Genetics Research Center, St. George's University of London, London, UK
| | | | - Joseph T Roland
- Section of Surgical Sciences, Vanderbilt University School of Medicine, Nashville, Tennessee.,Epithelial Biology Center, Vanderbilt University School of Medicine, Nashville, Tennessee.,Departments of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Amy C Engevik
- Section of Surgical Sciences, Vanderbilt University School of Medicine, Nashville, Tennessee.,Epithelial Biology Center, Vanderbilt University School of Medicine, Nashville, Tennessee.,Departments of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Ernest Cutz
- Division of Pathology, Department of Paediatric Laboratory Medicine, The Hospital for Sick Children, Toronto, Canada
| | - Thomas Müller
- Department of Paediatrics I, Medical University of Innsbruck, Innsbruck, Austria
| | - James R Goldenring
- Section of Surgical Sciences, Vanderbilt University School of Medicine, Nashville, Tennessee.,Epithelial Biology Center, Vanderbilt University School of Medicine, Nashville, Tennessee.,Departments of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Lukas A Huber
- Division of Cell Biology, Medical University of Innsbruck, Innsbruck, Austria
| | - Michael W Hess
- Division of Histology and Embryology, Medical University of Innsbruck, Innsbruck, Austria
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Vergés M. Retromer in Polarized Protein Transport. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2016; 323:129-79. [PMID: 26944621 DOI: 10.1016/bs.ircmb.2015.12.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Retromer is an evolutionary conserved protein complex required for endosome-to-Golgi retrieval of receptors for lysosomal hydrolases. It is constituted by a heterotrimer encoded by the vacuolar protein sorting (VPS) gene products Vps26, Vps35, and Vps29, which selects cargo, and a dimer of phosphoinositide-binding sorting nexins, which deforms the membrane. Recent progress in the mechanism of retromer assembly and functioning has strengthened the link between sorting at the endosome and cytoskeleton dynamics. Retromer is implicated in endosomal sorting of many cargos and plays an essential role in plant and animal development. Although it is best known for endosome sorting to the trans-Golgi network, it also intervenes in recycling to the plasma membrane. In polarized cells, such as epithelial cells and neurons, retromer may also be utilized for transcytosis and long-range transport. Considerable evidence implicates retromer in establishment and maintenance of cell polarity. That includes sorting of the apical polarity module Crumbs; regulation of retromer function by the basolateral polarity module Scribble; and retromer-dependent recycling of various cargoes to a certain surface domain, thus controlling polarized location and cell homeostasis. Importantly, altered retromer function has been linked to neurodegeneration, such as in Alzheimer's or Parkinson's disease. This review will underline how alterations in retromer localization and function may affect polarized protein transport and polarity establishment, thereby causing developmental defects and disease.
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Affiliation(s)
- Marcel Vergés
- Cardiovascular Genetics Group, Girona Biomedical Research Institute (IDIBGI), Girona, Spain; Medical Sciences Department, University of Girona, Girona, Spain.
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Abstract
Rab GTPases control intracellular membrane traffic by recruiting specific effector proteins to restricted membranes in a GTP-dependent manner. In this Cell Science at a Glance and the accompanying poster, we highlight the regulation of Rab GTPases by proteins that control their membrane association and activation state, and provide an overview of the cellular processes that are regulated by Rab GTPases and their effectors, including protein sorting, vesicle motility and vesicle tethering. We also discuss the physiological importance of Rab GTPases and provide examples of diseases caused by their dysfunctions.
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Affiliation(s)
- Yan Zhen
- Centre for Cancer Biomedicine, Faculty of Medicine, University of Oslo, Montebello, Oslo N-0379, Norway Department for Molecular Cell Biology, Institute for Cancer Research, Oslo University Hospital, Montebello, Oslo N-0379, Norway
| | - Harald Stenmark
- Centre for Cancer Biomedicine, Faculty of Medicine, University of Oslo, Montebello, Oslo N-0379, Norway Department for Molecular Cell Biology, Institute for Cancer Research, Oslo University Hospital, Montebello, Oslo N-0379, Norway
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Wang S, Ma Z, Xu X, Wang Z, Sun L, Zhou Y, Lin X, Hong W, Wang T. A role of Rab29 in the integrity of the trans-Golgi network and retrograde trafficking of mannose-6-phosphate receptor. PLoS One 2014; 9:e96242. [PMID: 24788816 PMCID: PMC4008501 DOI: 10.1371/journal.pone.0096242] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2013] [Accepted: 04/07/2014] [Indexed: 11/18/2022] Open
Abstract
Rab29 (also referred as Rab7L1) is a novel Rab protein, and is recently demonstrated to regulate phagocytosis and traffic from the Golgi to the lysosome. However, its roles in membrane trafficking have not been investigated extensively. Our results in this study revealed that Rab29 is associated with the trans-Golgi network (TGN), and is essential for maintaining the integrity of the TGN, because inhibition of the activity of Rab29 or depletion of Rab29 resulted in fragmentation of the TGN marked by TGN46. Expression of the dominant negative form Rab29T21N or shRNA-Rab29 also altered the distribution of mannose-6-phosphate receptor (M6PR), and interrupted the retrograde trafficking of M6PR through monitoring the endocytosis of CD8-tagged calcium dependent M6PR (cdM6PR) or calcium independent M6PR (ciM6PR), but without significant effects on the anterograde trafficking of vesicular stomatitis virus G protein (VSV-G). Our results suggest that Rab29 is essential for the integrity of the TGN and participates in the retrograde trafficking of M6PRs.
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Affiliation(s)
- Shicong Wang
- School of Pharmaceutical Sciences, State Key Laboratory of Cellular Stress Biology, Xiamen University, Xiamen, Fujian, China
| | - Zexu Ma
- School of Pharmaceutical Sciences, State Key Laboratory of Cellular Stress Biology, Xiamen University, Xiamen, Fujian, China
| | - Xiaohui Xu
- School of Pharmaceutical Sciences, State Key Laboratory of Cellular Stress Biology, Xiamen University, Xiamen, Fujian, China
| | - Zhen Wang
- School of Pharmaceutical Sciences, State Key Laboratory of Cellular Stress Biology, Xiamen University, Xiamen, Fujian, China
| | - Lixiang Sun
- School of Pharmaceutical Sciences, State Key Laboratory of Cellular Stress Biology, Xiamen University, Xiamen, Fujian, China
| | - Yunhe Zhou
- School of Pharmaceutical Sciences, State Key Laboratory of Cellular Stress Biology, Xiamen University, Xiamen, Fujian, China
| | - Xiaosi Lin
- School of Pharmaceutical Sciences, State Key Laboratory of Cellular Stress Biology, Xiamen University, Xiamen, Fujian, China
| | - Wanjin Hong
- School of Pharmaceutical Sciences, State Key Laboratory of Cellular Stress Biology, Xiamen University, Xiamen, Fujian, China
- Institute of Molecular and Cell Biology, A*STAR (Agency for Science, Technology and Research), Singapore, Singapore
| | - Tuanlao Wang
- School of Pharmaceutical Sciences, State Key Laboratory of Cellular Stress Biology, Xiamen University, Xiamen, Fujian, China
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Rab8 modulates metabotropic glutamate receptor subtype 1 intracellular trafficking and signaling in a protein kinase C-dependent manner. J Neurosci 2013; 32:16933-42a. [PMID: 23175844 DOI: 10.1523/jneurosci.0625-12.2012] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Metabotropic glutamate receptors (mGluRs) are G protein-coupled receptors (GPCRs) that are activated by glutamate, the primary excitatory neurotransmitter in the CNS. Alterations in glutamate receptor signaling are implicated in neuropathologies such as Alzheimer's disease, ischemia, and Huntington's disease among others. Group 1 mGluRs (mGluR1 and mGluR5) are primarily coupled to Gα(q/11) leading to the activation of phospholipase C and the formation of diacylglycerol and inositol 1,4,5-trisphosphate, which results in the release of intracellular calcium stores and protein kinase C (PKC) activation. Desensitization, endocytosis, and recycling are major mechanisms of GPCR regulation, and the intracellular trafficking of GPCRs is linked to the Rab family of small G proteins. Rab8 is a small GTPase that is specifically involved in the regulation of secretory/recycling vesicles, modulation of the actin cytoskeleton, and cell polarity. Rab8 has been shown to regulate the synaptic delivery of AMPA receptors during long-term potentiation and during constitutive receptor recycling. We show here that Rab8 interacts with the C-terminal tail of mGluR1a in an agonist-dependent manner and plays a role in regulating of mGluR1a signaling and intracellular trafficking in human embryonic kidney 293 cells. Specifically, Rab8 expression attenuates mGluR1a-mediated inositol phosphate formation and calcium release from mouse neurons in a PKC-dependent manner, while increasing cell surface mGluR1a expression via decreased receptor endocytosis. These experiments provide us with an understanding of the role Rabs play in coordinated regulation of mGluR1a and how this impacts mGluR1a signaling.
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Adenosine A2B receptor-mediated leukemia inhibitory factor release from astrocytes protects cortical neurons against excitotoxicity. J Neuroinflammation 2012; 9:198. [PMID: 22894638 PMCID: PMC3458985 DOI: 10.1186/1742-2094-9-198] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2012] [Accepted: 08/01/2012] [Indexed: 02/07/2023] Open
Abstract
Background Neuroprotective and neurotrophic properties of leukemia inhibitory factor (LIF) have been widely reported. In the central nervous system (CNS), astrocytes are the major source for LIF, expression of which is enhanced following disturbances leading to neuronal damage. How astrocytic LIF expression is regulated, however, has remained an unanswered question. Since neuronal stress is associated with production of extracellular adenosine, we investigated whether LIF expression in astrocytes was mediated through adenosine receptor signaling. Methods Mouse cortical neuronal and astrocyte cultures from wild-type and adenosine A2B receptor knock-out animals, as well as adenosine receptor agonists/antagonists and various enzymatic inhibitors, were used to study LIF expression and release in astrocytes. When needed, a one-way analysis of variance (ANOVA) followed by Bonferroni post-hoc test was used for statistical analysis. Results We show here that glutamate-stressed cortical neurons induce LIF expression through activation of adenosine A2B receptor subtype in cultured astrocytes and require signaling of protein kinase C (PKC), mitogen-activated protein kinases (MAPKs: p38 and ERK1/2), and the nuclear transcription factor (NF)-κB. Moreover, LIF concentration in the supernatant in response to 5′-N-ethylcarboxamide (NECA) stimulation was directly correlated to de novo protein synthesis, suggesting that LIF release did not occur through a regulated release pathway. Immunocytochemistry experiments show that LIF-containing vesicles co-localize with clathrin and Rab11, but not with pHogrin, Chromogranin (Cg)A and CgB, suggesting that LIF might be secreted through recycling endosomes. We further show that pre-treatment with supernatants from NECA-treated astrocytes increased survival of cultured cortical neurons against glutamate, which was absent when the supernatants were pre-treated with an anti-LIF neutralizing antibody. Conclusions Adenosine from glutamate-stressed neurons induces rapid LIF release in astrocytes. This rapid release of LIF promotes the survival of cortical neurons against excitotoxicity.
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MYO5B mutations in patients with microvillus inclusion disease presenting with transient renal Fanconi syndrome. J Pediatr Gastroenterol Nutr 2012; 54:491-8. [PMID: 22441677 DOI: 10.1097/mpg.0b013e3182353773] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
BACKGROUND AND OBJECTIVE : Microvillus inclusion disease (MVID) is a rare congenital enteropathy associated with brush border atrophy and reduced expression of enzymes at the enterocytes' apical surface. MVID is associated with mutations in the MYO5B gene, which is expressed in all epithelial tissues. Whether organs other than the intestine are affected in MVID is unclear. We report 2 patients with MVID that developed renal Fanconi syndrome while receiving total parenteral nutrition. Renal Fanconi syndrome has been correlated to apical plasma membrane defects in kidney proximal tubular epithelial cells. The aim of the present study was to determine whether MYO5B mutations in these patients correlate with similar apical plasma membrane defects in renal tubular epithelial cells as observed in the intestine. METHODS : Biopsies from kidney, duodenum, ileum, jejunum, and colon of 2 patients with MVID carrying MYO5B mutations and of age-matched controls were fixed in paraffin and analyzed with immunohistochemistry and transmission electron microscopy. RESULTS : Structural defects of the brush border and apical recycling endosome organization are observed in enterocytes of all of the segments of the small intestine and colon. MYO5B mutations in patients with MVID with renal Fanconi syndrome do not correlate with aberrant apical plasma membrane morphology or altered apical recycling endosome organization in renal tubular epithelial cells. CONCLUSIONS : MYO5B mutations have divergent effects on the apical membrane system in kidney and intestinal epithelial cells. Epithelial defects presented in MVID are therefore likely triggered by intestine-specific factors, the identification of which may provide new targets and open avenues for the development of alternative therapeutic strategies to combat this devastating disease.
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Progida C, Cogli L, Piro F, De Luca A, Bakke O, Bucci C. Rab7b controls trafficking from endosomes to the TGN. J Cell Sci 2010; 123:1480-91. [DOI: 10.1242/jcs.051474] [Citation(s) in RCA: 88] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Rab7b is a recently identified member of the Rab GTPase protein family and has high similarity to Rab7. It has been reported that Rab7b is lysosome associated, that it is involved in monocytic differentiation and that it promotes lysosomal degradation of TLR4 and TLR9. Here we investigated further the localization and function of this GTPase. We found that wild-type Rab7b is lysosome associated whereas an activated, GTP-bound form of Rab7b localizes to the Golgi apparatus. In contrast to Rab7, Rab7b is not involved in EGF and EGFR degradation. Depletion of Rab7b or expression of Rab7b T22N, a Rab7b dominant-negative mutant, impairs cathepsin-D maturation and causes increased secretion of hexosaminidase. Moreover, expression of Rab7b T22N or depletion of Rab7b alters TGN46 distribution, cation-independent mannose-6-phosphate receptor (CI-MPR) trafficking, and causes an increase in the levels of the late endosomal markers CI-MPR and cathepsin D. Vesicular stomatitis virus G protein (VSV-G) trafficking, by contrast, is normal in Rab7b-depleted or Rab7b-T22N-expressing cells. In addition, depletion of Rab7b prevents cholera toxin B-subunit from reaching the Golgi. Altogether, these data indicate that Rab7b is required for normal lysosome function, and, in particular, that it is an essential factor for retrograde transport from endosomes to the trans-Golgi network (TGN).
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Affiliation(s)
- Cinzia Progida
- Department of Biological and Environmental Sciences and Technologies (DiSTeBA), University of Salento, Via Provinciale Monteroni, 73100 Lecce, Italy
- Centre for Immune Regulation, Department of Molecular Biosciences, University of Oslo, 0316 Oslo, Norway
| | - Laura Cogli
- Department of Biological and Environmental Sciences and Technologies (DiSTeBA), University of Salento, Via Provinciale Monteroni, 73100 Lecce, Italy
| | - Francesco Piro
- Department of Biological and Environmental Sciences and Technologies (DiSTeBA), University of Salento, Via Provinciale Monteroni, 73100 Lecce, Italy
| | - Azzurra De Luca
- Department of Biological and Environmental Sciences and Technologies (DiSTeBA), University of Salento, Via Provinciale Monteroni, 73100 Lecce, Italy
| | - Oddmund Bakke
- Centre for Immune Regulation, Department of Molecular Biosciences, University of Oslo, 0316 Oslo, Norway
- The Gade Institute, University of Bergen, 5021 Bergen, Norway
| | - Cecilia Bucci
- Department of Biological and Environmental Sciences and Technologies (DiSTeBA), University of Salento, Via Provinciale Monteroni, 73100 Lecce, Italy
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Schardt A, Brinkmann BG, Mitkovski M, Sereda MW, Werner HB, Nave KA. The SNARE protein SNAP-29 interacts with the GTPase Rab3A: Implications for membrane trafficking in myelinating glia. J Neurosci Res 2010; 87:3465-79. [PMID: 19170188 DOI: 10.1002/jnr.22005] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
During myelin formation, vast amounts of specialized membrane proteins and lipids are trafficked toward the growing sheath in cell surface-directed transport vesicles. Soluble N-ethylmaleimide-sensitive factor (NSF) attachment proteins (SNAPs) are important components of molecular complexes required for membrane fusion. We have analyzed the expression profile and molecular interactions of SNAP-29 in the nervous system. In addition to its known enrichment in neuronal synapses, SNAP-29 is abundant in oligodendrocytes during myelination and in noncompact myelin of the peripheral nervous system. By yeast two-hybrid screen and coimmunoprecipitation, we found that the GTPases Rab3A, Rab24, and septin 4 bind to the N-terminal domain of SNAP-29. The interaction with Rab24 or septin 4 was GTP independent. In contrast, interaction between SNAP-29 and Rab3A was GTP dependent, and colocalization was extensive both in synapses and in myelinating glia. In HEK293 cells, cytoplasmic SNAP-29 pools were redistributed upon coexpression with Rab3A, and surface-directed trafficking of myelin proteolipid protein was enhanced by overexpression of SNAP-29 and Rab3A. Interestingly, the abundance of SNAP-29 in sciatic nerves was increased during remyelination and in a rat model of Charcot-Marie-Tooth disease, two pathological situations with increased myelin membrane biogenesis. We suggest that Rab3A may regulate SNAP-29-mediated membrane fusion during myelination.
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Affiliation(s)
- Anke Schardt
- Department of Neurogenetics, Max-Planck-Institute of Experimental Medicine, Göttingen, Germany
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The epithelial polarity program: machineries involved and their hijacking by cancer. Oncogene 2008; 27:6939-57. [DOI: 10.1038/onc.2008.345] [Citation(s) in RCA: 135] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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Ng EL, Tang BL. Rab GTPases and their roles in brain neurons and glia. ACTA ACUST UNITED AC 2008; 58:236-46. [PMID: 18485483 DOI: 10.1016/j.brainresrev.2008.04.006] [Citation(s) in RCA: 112] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2007] [Revised: 02/29/2008] [Accepted: 04/06/2008] [Indexed: 12/19/2022]
Affiliation(s)
- Ee Ling Ng
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, 8 Medical Drive, Singapore 117597, Singapore
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Evans E, Zhang W, Jerdeva G, Chen CY, Chen X, Hamm-Alvarez SF, Okamoto CT. Direct interaction between Rab3D and the polymeric immunoglobulin receptor and trafficking through regulated secretory vesicles in lacrimal gland acinar cells. Am J Physiol Cell Physiol 2008; 294:C662-74. [PMID: 18171724 DOI: 10.1152/ajpcell.00623.2006] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The lacrimal gland is responsible for tear production, and a major protein found in tears is secretory component (SC), the proteolytically cleaved fragment of the extracellular domain of the polymeric Ig receptor (pIgR), which is the receptor mediating the basal-to-apical transcytosis of polymeric immunoglobulins across epithelial cells. Immunofluorescent labeling of rabbit lacrimal gland acinar cells (LGACs) revealed that the small GTPase Rab3D, a regulated secretory vesicle marker, and the pIgR are colocalized in subapical membrane vesicles. In addition, the secretion of SC from primary cultures of LGACs was stimulated by the cholinergic agonist carbachol (CCH), and its release rate was very similar to that of other regulated secretory proteins in LGACs. In pull-down assays from resting LGACs, recombinant wild-type Rab3D (Rab3DWT) or the GDP-locked mutant Rab3DT36N both pulled down pIgR, but the GTP-locked mutant Rab3DQ81L did not. When the pull-down assays were performed in the presence of guanosine-5'-(gamma-thio)-triphosphate, GTP, or guanosine-5'-O-(2-thiodiphosphate), binding of Rab3DWT to pIgR was inhibited. In blot overlays, recombinant Rab3DWT bound to immunoprecipitated pIgR, suggesting that Rab3D and pIgR may interact directly. Adenovirus-mediated overexpression of mutant Rab3DT36N in LGACs inhibited CCH-stimulated SC release, and, in CCH-stimulated LGACs, pull down of pIgR with Rab3DWT and colocalization of pIgR with endogenous Rab3D were decreased relative to resting cells, suggesting that the pIgR-Rab3D interaction may be modulated by secretagogues. These data suggest that the novel localization of pIgR to the regulated secretory pathway of LGACs and its secretion therefrom may be affected by its novel interaction with Rab3D.
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Affiliation(s)
- Eunbyul Evans
- Dept. of Pharmacology and Pharmaceutical Sciences, Univ. of Southern California, Los Angeles, CA 90089-9121, USA
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Ishida-Yamamoto A, Kishibe M, Takahashi H, Iizuka H. Rab11 Is Associated with Epidermal Lamellar Granules. J Invest Dermatol 2007; 127:2166-70. [PMID: 17476295 DOI: 10.1038/sj.jid.5700850] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Epidermal lamellar granules (LGs) are specialized organelles that transport and secrete various molecules, including lipids, proteases, protease inhibitors, and structural proteins, thereby providing a protective barrier against the environment. Abnormalities in LG-related molecules result in severe skin diseases, but their transport mechanisms are poorly understood. We studied the distribution of Rab11, a common GTPase in recycling endosomes, in normal human epidermis. Confocal laser scanning microscopy detected Rab11 immunoreactivity in differentiated epidermal keratinocytes. Staining was strong at the apical side of each cell, a pattern commonly seen in LG-associated molecules. Around the nuclei, Rab11 was colocalized with TGN46, a trans-Golgi network marker. Rab11 was also colocalized with known LG-molecules, namely lymphoepithelial Kazal-type-related inhibitor, corneodesmosine, cathepsin D, and glucosylceramides. Immunoelectron microscopy revealed that Rab11 was widely distributed along TGN and tubular-vesicular structures containing different LG molecules. The present results suggest that Rab11 plays a role in the intracellular trafficking of various types of LG-molecule from the TGN to the cell surface.
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Takahashi M, Murate M, Fukuda M, Sato SB, Ohta A, Kobayashi T. Cholesterol controls lipid endocytosis through Rab11. Mol Biol Cell 2007; 18:2667-77. [PMID: 17475773 PMCID: PMC1924824 DOI: 10.1091/mbc.e06-10-0924] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Cellular cholesterol increases when cells reach confluency in Chinese hamster ovary (CHO) cells. We examined the endocytosis of several lipid probes in subconfluent and confluent CHO cells. In subconfluent cells, fluorescent lipid probes including poly(ethylene glycol)derivatized cholesterol, 22-(N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino)-23,24-bisnor-5-cholen-3beta-ol, and fluorescent sphingomyelin analogs were internalized to pericentriolar recycling endosomes. This accumulation was not observed in confluent cells. Internalization of fluorescent lactosylceramide was not affected by cell confluency, suggesting that the endocytosis of specific membrane components is affected by cell confluency. The crucial role of cellular cholesterol in cell confluency-dependent endocytosis was suggested by the observation that the fluorescent sphingomyelin was transported to recycling endosomes when cellular cholesterol was depleted in confluent cells. To understand the molecular mechanism(s) of cell confluency- and cholesterol-dependent endocytosis, we examined intracellular distribution of rab small GTPases. Our results indicate that rab11 but not rab4, altered intracellular localization in a cell confluency-associated manner, and this alteration was dependent on cell cholesterol. In addition, the expression of a constitutive active mutant of rab11 changed the endocytic route of lipid probes from early to recycling endosomes. These results thus suggest that cholesterol controls endocytic routes of a subset of membrane lipids through rab11.
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Affiliation(s)
- Miwa Takahashi
- *Frontier Research System
- Department of Biotechnology, The University of Tokyo, Bunkyo-ku, Tokyo 113-8657, Japan
| | | | - Mitsunori Fukuda
- Fukuda Initiative Research Unit, and
- Department of Developmental Biology and Neurosciences, Graduate School of Life Sciences, Tohoku University, Miyagi 980-8578, Japan
| | - Satoshi B. Sato
- *Frontier Research System
- Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan; and
| | - Akinori Ohta
- Department of Biotechnology, The University of Tokyo, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Toshihide Kobayashi
- *Frontier Research System
- Lipid Biology Laboratory, RIKEN, Wako, Saitama 351-0198, Japan
- Institut National de la Santé et de la Recherche Médicale U870, Institut National de la Recherche Agronomique U1235, Institut National des Sciences Appliquées de Lyon, University Lyon 1 and Hospices Civils de Lyon, 69621 Villeurbanne, France
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16
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Coutelis JB, Ephrussi A. Rab6 mediates membrane organization and determinant localization during Drosophila oogenesis. Development 2007; 134:1419-30. [PMID: 17329360 DOI: 10.1242/dev.02821] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
The Drosophila melanogaster body axes are defined by the precise localization and the restriction of molecular determinants in the oocyte. Polarization of the oocyte during oogenesis is vital for this process. The directed traffic of membranes and proteins is a crucial component of polarity establishment in various cell types and organisms. Here, we investigate the role of the small GTPase Rab6 in the organization of the egg chamber and in asymmetric determinant localization during oogenesis. We show that exocytosis is affected in rab6-null egg chambers, which display a loss of nurse cell plasma membranes. Rab6 is also required for the polarization of the oocyte microtubule cytoskeleton and for the posterior localization of oskar mRNA. We show that, in vivo, Rab6 is found in a complex with Bicaudal-D, and that Rab6 and Bicaudal-D cooperate in oskar mRNA localization. Thus, during Drosophila oogenesis, Rab6-dependent membrane trafficking is doubly required; first, for the general organization and growth of the egg chamber, and second, more specifically, for the polarization of the microtubule cytoskeleton and localization of oskar mRNA. These findings highlight the central role of vesicular trafficking in the establishment of polarity and in determinant localization in Drosophila.
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Affiliation(s)
- Jean-Baptiste Coutelis
- Developmental Biology Unit, European Molecular Biology Laboratory, Meyerhofstrasse 1, D-69117 Heidelberg, Germany
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17
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Kim JT, Cho MY, Choi SC, Kim JW, Chae SK, Yoon DY, Kim JW, Lim JS. Prenylated Rab acceptor 1 (PRA1) inhibits TCF/β-catenin signaling by binding to β-catenin. Biochem Biophys Res Commun 2006; 349:200-8. [PMID: 16930546 DOI: 10.1016/j.bbrc.2006.08.026] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2006] [Accepted: 08/05/2006] [Indexed: 11/24/2022]
Abstract
The prenylated Rab acceptor 1 (PRA1) is a ubiquitously expressed 21 kDa protein containing two transmembrane domains that possibly induce its localization to the Golgi complex. It binds to prenylated Rab GTPases and VAMP2. In this study, we report that PRA1-overexpressing cells exhibited a significantly retarded growth rate as compared to that of the mock-transfected cells, and the transcriptional activity of TCF, as evaluated by TOPflash luciferase reporter assay, was profoundly reduced in the PRA1-overexpressed cells. These intracellular functions of PRA1 were verified by introducing deletion mutant or site-directed mutants, or small interfering RNA of PRA1. In addition, the translocation of beta-catenin from the cytosol to the nucleus was blocked to a significant degree in the PRA1-cells, and the interaction of PRA1 and beta-catenin was identified by confocal microscopy and immunoprecipitation analysis. Finally, we observed that the inhibition of TCF/beta-catenin signaling by PRA1 is associated with ERK1/2 dephosphorylation. Therefore, our data suggest that the in vivo modulation of PRA1 may be involved in TCF/beta-catenin signaling, as well as cellular proliferation and tumorigenesis.
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Affiliation(s)
- Jong-Tae Kim
- Department of Biological Sciences, Sookmyung Women's University, Seoul 140-742, Republic of Korea
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18
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Strick DJ, Elferink LA. Rab15 effector protein: a novel protein for receptor recycling from the endocytic recycling compartment. Mol Biol Cell 2005; 16:5699-709. [PMID: 16195351 PMCID: PMC1289414 DOI: 10.1091/mbc.e05-03-0204] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Sorting endosomes and the endocytic recycling compartment are critical intracellular stores for the rapid recycling of internalized membrane receptors to the cell surface in multiple cell types. However, the molecular mechanisms distinguishing fast receptor recycling from sorting endosomes and slow receptor recycling from the endocytic recycling compartment remain poorly understood. We previously reported that Rab15 differentially regulates transferrin receptor trafficking through sorting endosomes and the endocytic recycling compartment, suggesting a role for distinct Rab15-effector interactions at these endocytic compartments. In this study, we identified the novel protein Rab15 effector protein (REP15) as a binding partner for Rab15-GTP. REP15 is compartment specific, colocalizing with Rab15 and Rab11 on the endocytic recycling compartment but not with Rab15, Rab4, or early endosome antigen 1 on sorting endosomes. REP15 interacts directly with Rab15-GTP but not with Rab5 or Rab11. Consistent with its localization, REP15 overexpression and small interfering RNA-mediated depletion inhibited transferrin receptor recycling from the endocytic recycling compartment, without affecting receptor entry into or recycling from sorting endosomes. Our data identify REP15 as a compartment-specific protein for receptor recycling from the endocytic recycling compartment, highlighting that the rapid and slow modes of transferrin receptor recycling are mechanistically distinct pathways.
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Affiliation(s)
- David J Strick
- Department of Neuroscience and Cell Biology, University of Texas Medical Branch, Galveston, TX 77555-1043, USA
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19
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Welte MA, Cermelli S, Griner J, Viera A, Guo Y, Kim DH, Gindhart JG, Gross SP. Regulation of Lipid-Droplet Transport by the Perilipin Homolog LSD2. Curr Biol 2005; 15:1266-75. [PMID: 16051169 DOI: 10.1016/j.cub.2005.06.062] [Citation(s) in RCA: 130] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2005] [Accepted: 06/14/2005] [Indexed: 01/15/2023]
Abstract
BACKGROUND Motor-driven transport along microtubules is a primary mechanism for moving and positioning organelles. How such transport is regulated remains poorly understood. For lipid droplets in Drosophila embryos, three distinct phases of transport can be distinguished. To identify factors regulating this transport, we biochemically purified droplets from individual phases and used 2D gel analysis to search for proteins whose amount on droplets changes as motion changes. RESULTS By mass spectrometry, we identified one such protein as LSD2. Similar to its mammalian counterpart Perilipin, LSD2 is responsible for regulating lipid homeostasis. Using specific antibodies, we confirmed that LSD2 is present on embryonic lipid droplets. We find that lack of LSD2 causes a specific transport defect: Droplet distribution fails to undergo the dramatic changes characteristic of the wild-type. This defect is not due to a complete failure of the core transport machinery--individual droplets still move bidirectionally along microtubules with approximately normal velocities and kinetics. Rather, detailed biophysical analysis suggests that developmental control of droplet motion is lost. We show that LSD2 is multiply phosphorylated in a developmentally controlled manner. LSD2 phosphorylation depends on the transacting signal Halo, and LSD2 can physically interact with the lipid-droplet-associated coordinator Klar, identifying LSD2 as a central player in the mechanisms that control droplet motion. CONCLUSIONS LSD2 appears to represent a new class of regulators, a protein that transduces regulatory signals to a separable core motor machinery. In addition, the demonstration that LSD2 regulates both transport and lipid metabolism suggests a link between lipid-droplet motion and lipid homeostasis.
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Affiliation(s)
- Michael A Welte
- Rosenstiel Biomedical Research Center, Brandeis University, 415 South Street, Waltham, Massachusetts 02454, USA
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20
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Ward ES, Martinez C, Vaccaro C, Zhou J, Tang Q, Ober RJ. From sorting endosomes to exocytosis: association of Rab4 and Rab11 GTPases with the Fc receptor, FcRn, during recycling. Mol Biol Cell 2005; 16:2028-38. [PMID: 15689494 PMCID: PMC1073680 DOI: 10.1091/mbc.e04-08-0735] [Citation(s) in RCA: 145] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
A longstanding question in cell biology is how is the routing of intracellular organelles within cells regulated? Although data support the involvement of Rab4 and Rab11 GTPases in the recycling pathway, the function of Rab11 in particular is uncertain. Here we have analyzed the association of these two Rab GTPases with the Fc receptor, FcRn, during intracellular trafficking. This Fc receptor is both functionally and structurally distinct from the classical Fcgamma receptors and transports immunoglobulin G (IgG) within cells. FcRn is therefore a recycling receptor that sorts bound IgG from unbound IgG in sorting endosomes. In the current study we have used dual color total internal reflection fluorescence microscopy (TIRFM) and wide-field imaging of live cells to analyze the events in human endothelial cells that are involved in the trafficking of FcRn positive (FcRn(+)) recycling compartments from sorting endosomes to exocytic sites at the plasma membrane. Our data are consistent with the following model for this pathway: FcRn leaves sorting endosomes in Rab4(+)Rab11(+) or Rab11(+) compartments. For Rab4(+)Rab11(+) compartments, Rab4 depletion occurs by segregation of the two Rab proteins into discrete domains that can separate. The Rab11(+)FcRn(+) vesicle or tubule subsequently fuses with the plasma membrane in an exocytic event. In contrast to Rab11, Rab4 is not involved in exocytosis.
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Affiliation(s)
- E Sally Ward
- Center for Immunology, University of Texas Southwestern Medical Center, Dallas, 75390-8576, USA.
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Rodriguez-Boulan E, Müsch A, Le Bivic A. Epithelial trafficking: new routes to familiar places. Curr Opin Cell Biol 2005; 16:436-42. [PMID: 15261677 DOI: 10.1016/j.ceb.2004.06.013] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Research carried out in mammalian epithelial cell systems over the past 25 years has delineated pathways and sorting signals involved in polarized delivery of plasma membrane proteins. Recently some progress has been made in the identification of mechanisms underlying this polarized trafficking and in the visualization of trafficking routes in live cells. A promising area of research is the study of trafficking functions of novel polarity genes identified in Drosophila and Caenorhabditis elegans.
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Affiliation(s)
- Enrique Rodriguez-Boulan
- Margaret Dyson Vision Research Institute, Weill Medical College of Cornell University, 1300 York Ave, New York, New York 10021, USA.
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22
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Hoekstra D, Tyteca D, van IJzendoorn SCD. The subapical compartment: a traffic center in membrane polarity development. J Cell Sci 2005; 117:2183-92. [PMID: 15126620 DOI: 10.1242/jcs.01217] [Citation(s) in RCA: 123] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Spatially separated apical and basolateral plasma membrane domains that have distinct functions and molecular compositions are a characteristic feature of epithelial cell polarity. The subapical compartment (SAC), also known as the common endosome (CE), where endocytic pathways from both surfaces merge, plays a crucial role in the maintenance and probably the biogenesis of these distinct membrane domains. Although differences in morphology are apparent, the same principal features of a SAC can be distinguished in different types of epithelial cells. As polarity develops, the compartment acquires several distinct machineries that, in conjunction with the cytoskeleton, are necessary for polarized trafficking. Disrupting trafficking via the SAC and hence bypassing its sorting machinery, as occurs upon actin depolymerization, leads to mis-sorting of apical and basolateral molecules, thereby compromising the development of polarity. The structural and functional integrity of the compartment in part depends on microtubules. Moreover, the acquisition of a particular set of Rab proteins, including Rab11 and Rab3, appears to be crucial in regulating molecular sorting and vesicular transport relevant both to recycling to either plasma membrane domain and to de novo assembly of the apical domain. Furthermore, subcompartmentalization of the SAC appears to be key to its various functions.
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Affiliation(s)
- Dick Hoekstra
- Department of Membrane Cell Biology, University of Groningen, Antonius Deusinglaan 1, 9713 AV Groningen, The Netherlands.
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Brahmaraju M, Shoeb M, Laloraya M, Kumar PG. Spatio-temporal organization of Vam6P and SNAP on mouse spermatozoa and their involvement in sperm-zona pellucida interactions. Biochem Biophys Res Commun 2004; 318:148-55. [PMID: 15110766 DOI: 10.1016/j.bbrc.2004.04.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2004] [Indexed: 12/01/2022]
Abstract
Acrosomal assembly during spermatogenesis and acrosome reaction during sperm-oocyte interaction are unique events of vesicle synthesis, transport, and fusion leading to fertilization. SNARE complex formation is essential for membrane fusion, and vesicle-associated (v-) SNARE intertwines with target membrane (t-) SNARE to form a coiled coil that bridges two membranes and facilitates fusion. We detected messages of Vam6P and SNAP in mammalian testis and epididymis. Vam6P and SNAP were detected in a temporally organized fashion on the spermatozoa from testis and epididymis, which showed accumulation on the principal acrosomal domains during capacitation. Vam6P and SNAP were shed off from the principal acrosomal domain after acrosome reaction, but the equatorial and the post-acrosomal domains retained these proteins. Antibodies to VAMP and SNAP inhibited sperm-zona pellucida interaction, suggesting their possible involvement in sperm membrane vesiculation.
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Affiliation(s)
- M Brahmaraju
- Molecular Reproduction Unit, School of Life Sciences, Devi Ahilya University, Vigyan Bhawan, Khandwa Road, Indore 452 001, MP, India
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