title: Dynamic assembly of the exomer secretory vesicle cargo adaptor subunits.
abstract: The trans-Golgi network (TGN) is the main secretory pathway sorting station, where cargoes are packed into appropriate transport vesicles targeted to specific destinations. Exomer is a cargo adaptor necessary for direct transport of a subset of cargoes from the TGN to the plasma membrane in yeast. Here, we show that unlike classical adaptor complexes, exomer is not recruited en bloc to the TGN, but rather assembles through a stepwise pathway, in which first the scaffold protein Chs5 and then the cargo-binding units, the ChAPs, are recruited. Although all ChAPs are able to assemble functional exomer complexes, they do so with different efficiencies. The mutual relationship between ChAPs varies from cooperation to competition depending on their expression levels and affinities to Chs5 allowing an optimized and efficient cargo transport. The multifactorial assembly pathway results in an exquisitely fine-tuned adaptor complex, enabling the cell to quickly respond and adapt to changes such as stress.
authors.affiliation: Growth & Development, Biozentrum, University of Basel, Basel, Switzerland.
authors.forename: Martina
authors.initials: M
authors.lastname: Huranova
authors.affiliation: Growth & Development, Biozentrum, University of Basel, Basel, Switzerland.
authors.forename: Gopinath
authors.initials: G
authors.lastname: Muruganandam
authors.affiliation: Experimental Physics I, University of Bayreuth, Bayreuth, Germany.
authors.forename: Matthias
authors.initials: M
authors.lastname: Weiss
authors.affiliation: Growth & Development, Biozentrum, University of Basel, Basel, Switzerland anne.spang@unibas.ch.
authors.forename: Anne
authors.initials: A
authors.lastname: Spang
mesh_terms: D033942:Adaptor Proteins, Vesicular Transport / Q000235:genetics / Q000378:metabolism*; D002687:Chitin Synthase / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D021381:Protein Transport; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D022142:Secretory Vesicles / Q000378:metabolism*; D021601:trans-Golgi Network / Q000378:metabolism
chemical_list: D033942:Adaptor Proteins, Vesicular Transport; C509470:CHS6 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; C491360:CHS5 protein, S cerevisiae; D002687:Chitin Synthase
keywords: FCS; FRAP; Golgi‐plasma membrane transport; cargo adaptor; quantitative analysis