Published in

American Society for Cell Biology, Molecular Biology of the Cell, 22(23), p. 4402-4415

DOI: 10.1091/mbc.e11-12-1015

Links

Tools

Export citation

Search in Google Scholar

The complex interactions of Chs5p, the ChAPs, and the cargo Chs3p

Journal article published in 2012 by Uli Rockenbauch, Alicja M. Ritz, Carlos Sacristan ORCID, Cesar Roncero, Anne Spang
This paper is made freely available by the publisher.
This paper is made freely available by the publisher.

Full text: Download

Red circle
Preprint: archiving forbidden
Green circle
Postprint: archiving allowed
Orange circle
Published version: archiving restricted
Data provided by SHERPA/RoMEO

Abstract

The exomer complex is a putative vesicle coat required for the direct transport of a subset of cargoes from the trans-Golgi network (TGN) to the plasma membrane. Exomer comprises Chs5p as well as the ChAPs family of proteins (Chs6p, Bud7p, Bch1p and Bch2p), which are thought to act as cargo receptors, and in particular Chs6p is required for the transport of the chitin synthase Chs3p to the bud neck. However, how the ChAPs associate with Chs5p and recognize cargo is not well understood. Using domain-switch chimeras of Chs6p and Bch2p we show that four tetratricopeptide repeats (TPRs) are involved in interaction with Chs5p. Since these roles are conserved between the ChAPs, the TPRs are interchangeable between different ChAP proteins. In contrast, the N-terminal and the central parts of the ChAPs contribute to cargo specificity. While the entire N-terminal domain of Chs6p is required for Chs3p export at all cell cycle stages, the central part seems to predominantly favor Chs3p export in small-budded cells. The cargo Chs3p probably also uses a complex motif for the interaction with Chs6, as the C-terminus of Chs3p interacts with Chs6p and is necessary, but not sufficient, for TGN export.