| Structural highlights
Function
[CHS6_YEAST] Member of the CHS5-ARF1P-binding proteins (CHAPS) which mediates export of specific cargo proteins, including chitin synthase CHS3.[1] [2] [3] [4] [5] [6] [7]
Publication Abstract from PubMed
Cargo adaptors control intracellular trafficking of transmembrane proteins by sorting them into membrane transport carriers. The COPI, COPII, and clathrin cargo adaptors are structurally well characterized, but other cargo adaptors remain poorly understood. Exomer is a specialized cargo adaptor that sorts specific proteins into trans-Golgi network (TGN)-derived vesicles in response to cellular signals. Exomer is recruited to the TGN by the Arf1 GTPase, a universally conserved trafficking regulator. Here, we report the crystal structure of a tetrameric exomer complex composed of two copies each of the Chs5 and Chs6 subunits. The structure reveals the FN3 and BRCT domains of Chs5, which together we refer to as the FBE domain (FN3-BRCT of exomer), project from the exomer core complex. The overall architecture of the FBE domain is reminiscent of the appendage domains of other cargo adaptors, although it exhibits a distinct topology. In contrast to appendage domains, which bind accessory factors, we show that the primary role of the FBE domain is to bind Arf1 for recruitment of exomer to membranes.
The exomer cargo adaptor structure reveals a novel GTPase-binding domain.,Paczkowski JE, Richardson BC, Strassner AM, Fromme JC EMBO J. 2012 Sep 21. doi: 10.1038/emboj.2012.268. PMID:23000721[8]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Bulawa CE. CSD2, CSD3, and CSD4, genes required for chitin synthesis in Saccharomyces cerevisiae: the CSD2 gene product is related to chitin synthases and to developmentally regulated proteins in Rhizobium species and Xenopus laevis. Mol Cell Biol. 1992 Apr;12(4):1764-76. PMID:1532231
- ↑ Ziman M, Chuang JS, Tsung M, Hamamoto S, Schekman R. Chs6p-dependent anterograde transport of Chs3p from the chitosome to the plasma membrane in Saccharomyces cerevisiae. Mol Biol Cell. 1998 Jun;9(6):1565-76. PMID:9614194
- ↑ Lesage G, Shapiro J, Specht CA, Sdicu AM, Menard P, Hussein S, Tong AH, Boone C, Bussey H. An interactional network of genes involved in chitin synthesis in Saccharomyces cerevisiae. BMC Genet. 2005 Feb 16;6:8. PMID:15715908 doi:10.1186/1471-2156-6-8
- ↑ Trautwein M, Schindler C, Gauss R, Dengjel J, Hartmann E, Spang A. Arf1p, Chs5p and the ChAPs are required for export of specialized cargo from the Golgi. EMBO J. 2006 Mar 8;25(5):943-54. Epub 2006 Feb 23. PMID:16498409 doi:7601007
- ↑ Lam KK, Davey M, Sun B, Roth AF, Davis NG, Conibear E. Palmitoylation by the DHHC protein Pfa4 regulates the ER exit of Chs3. J Cell Biol. 2006 Jul 3;174(1):19-25. PMID:16818716 doi:jcb.200602049
- ↑ Wang CW, Hamamoto S, Orci L, Schekman R. Exomer: A coat complex for transport of select membrane proteins from the trans-Golgi network to the plasma membrane in yeast. J Cell Biol. 2006 Sep 25;174(7):973-83. PMID:17000877 doi:10.1083/jcb.200605106
- ↑ Sanchatjate S, Schekman R. Chs5/6 complex: a multiprotein complex that interacts with and conveys chitin synthase III from the trans-Golgi network to the cell surface. Mol Biol Cell. 2006 Oct;17(10):4157-66. Epub 2006 Jul 19. PMID:16855022 doi:10.1091/mbc.E06-03-0210
- ↑ Paczkowski JE, Richardson BC, Strassner AM, Fromme JC. The exomer cargo adaptor structure reveals a novel GTPase-binding domain. EMBO J. 2012 Sep 21. doi: 10.1038/emboj.2012.268. PMID:23000721 doi:http://dx.doi.org/10.1038/emboj.2012.268
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