Journal article
Mammalian Late Vacuole Protein Sorting Orthologues Participate in Early Endosomal Fusion and Interact with the Cytoskeleton
Molecular biology of the cell, Vol.15(3), pp.1197-1210
03/01/2004
DOI: 10.1091/mbc.E03-06-0358
PMCID: PMC363107
PMID: 14668490
Abstract
In
Saccharomyces cerevisiae
, the class C vacuole protein sorting (Vps) proteins, together with Vam2p/Vps41p and Vam6p/Vps39p, form a complex that interacts with soluble
N
-ethylmaleimide-sensitive factor attachment protein receptor and Rab proteins to “tether” vacuolar membranes before fusion. To determine a role for the corresponding mammalian orthologues, we examined the function, localization, and protein interactions of endogenous mVps11, mVps16, mVps18, mVam2p, and mVam6. We found a significant proportion of these proteins localized to early endosome antigen-1 and transferrin receptor-positive early endosomes in Vero, normal rat kidney, and Chinese hamster ovary cells. Immunoprecipitation experiments showed that mVps18 not only interacted with Syntaxin (Syn)7, vesicle-associated membrane protein 8, and Vti1-b but also with Syn13, Syn6, and the Sec1/Munc18 protein mVps45, which catalyze early endosomal fusion events. Moreover, anti-mVps18 antibodies inhibited early endosome fusion in vitro. Mammalian mVps18 also associated with mVam2 and mVam6 as well as with the microtubule-associated Hook1 protein, an orthologue of the
Drosophila
Hook protein involved in endosome biogenesis. Using in vitro binding and immunofluorescence experiments, we found that mVam2 and mVam6 also associated with microtubules, whereas mVps18, mVps16, and mVps11 associated with actin filaments. These data indicate that the late Vps proteins function during multiple soluble
N
-ethylmaleimide-sensitive factor attachment protein receptor-mediated fusion events throughout the endocytic pathway and that their activity may be coordinated with cytoskeletal function.
Details
- Title: Subtitle
- Mammalian Late Vacuole Protein Sorting Orthologues Participate in Early Endosomal Fusion and Interact with the Cytoskeleton
- Creators
- Simon C. W. Richardson - University of IowaStanley C. Winistorfer - University of IowaViviane Poupon - Cambridge Institute for Medical Research and Department of Clinical Biochemistry, University of Cambridge, Addenbrookes Hospital, Cambridge CB2 2XY, United KingdomJ. Paul Luzio - Cambridge Institute for Medical Research and Department of Clinical Biochemistry, University of Cambridge, Addenbrookes Hospital, Cambridge CB2 2XY, United KingdomRobert C. Piper - University of Iowa
- Resource Type
- Journal article
- Publication Details
- Molecular biology of the cell, Vol.15(3), pp.1197-1210
- Publisher
- The American Society for Cell Biology
- DOI
- 10.1091/mbc.E03-06-0358
- PMID
- 14668490
- PMCID
- PMC363107
- ISSN
- 1059-1524
- eISSN
- 1939-4586
- Language
- English
- Date published
- 03/01/2004
- Academic Unit
- Molecular Physiology and Biophysics; Medicine Administration; Internal Medicine
- Record Identifier
- 9984297601902771
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