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Author Notes:

Address correspondence to: Victor Faundez (Email: faundez@cellbio.emory.edu).

We are indebted to the Faundez lab members for their comments.

Subject:

Research Funding:

This work was supported by grants from the National Institutes of Health to V.F. (NS42599 and GM077569) and to S.W.L. (GM082932) and by the University Research Committee.

S.A.Z. was supported by T32 GM008367, National Institutes of Health, Training Program in Biochemistry, Cell, and Molecular Biology.

The work was also supported by the Neuronal Imaging and Lentiviral Cores of the Emory Neuroscience NINDS Core Facilities Grant P30NS055077.

Clathrin-dependent mechanisms modulate the subcellular distribution of class C Vps/HOPS tether subunits in polarized and nonpolarized cells

Journal Title:

Molecular Biology of the Cell

Volume:

Volume 22, Number 10

Publisher:

, Pages 1699-1715

Type of Work:

Article | Final Publisher PDF

Abstract:

Coats define the composition of carriers budding from organelles. In addition, coats interact with membrane tethers required for vesicular fusion. The yeast AP-3 (Adaptor Protein Complex 3) coat and the class C Vps/HOPS (HOmotypic fusion and Protein Sorting) tether follow this model as their interaction occurs at the carrier fusion step. Here we show that mammalian Vps class C/HOPS subunits and clathrin interact and that acute perturbation of clathrin function disrupts the endosomal distribution of Vps class C/HOPS tethers in HEK293T and polarized neuronal cells. Vps class C/HOPS subunits and clathrin exist in complex with either AP-3 or hepatocyte growth factor receptor substrate (Hrs). Moreover, Vps class C/HOPS proteins cofractionate with clathrin-coated vesicles, which are devoid of Hrs. Expression of FK506 binding protein (FKBP)–clathrin light chain chimeras, to inhibit clathrin membrane association dynamics, increased Vps class C/HOPS subunit content in rab5 endosomal compartments. Additionally, Vps class C/HOPS subunits were concentrated at tips of neuronal processes, and their delivery was impaired by expression of FKBP–clathrin chimeras and AP20187 incubation. These data support a model in which Vps class C/HOPS subunits incorporate into clathrin-coated endosomal domains and carriers in mammalian cells. We propose that vesicular (AP-3) and nonvesicular (Hrs) clathrin mechanisms segregate class C Vps/HOPS tethers to organelles and domains of mammalian cells bearing complex architectures.

Copyright information:

© 2011 Zlatic et al. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License

This is an Open Access work distributed under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License (http://creativecommons.org/licenses/by-nc-sa/3.0/).

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