The yeast clathrin adaptor protein complex 1 is required for the efficient retention of a subset of late Golgi membrane proteins.
In yeast, certain resident trans-Golgi network (TGN) proteins achieve steady-state localization by cycling through late endosomes. Here, we show that chitin synthase III (Chs3p), an enzyme involved in the assembly of the cell wall at the mother-bud junction, populates an intracellular reservoir that is maintained by a cycle of transport between the TGN and early endosomes. Traffic of Chs3p from the TGN/early endosome to the cell surface requires CHS5 and CHS6, mutant alleles of which trap Chs3p in the TGN/early endosome. Disruption of the clathrin adaptor protein complex 1 (AP-1) restores Chs3p transport to the plasma membrane. Similarly, in AP-1 deficient cells, the resident TGN/early endosome syntaxin, Tlg1p, is missorted. We propose that clathrin and AP-1 act to recycle Chs3p and Tlg1p from the early endosome to the TGN.
Valdivia
Raphael H
RH
Howard Hughes Medical Institute and Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA.
Baggott
Daniel
D
Chuang
John S
JS
Schekman
Randy W
RW
D033942:Adaptor Proteins, Vesicular Transport; D002352:Carrier Proteins / Q000235:genetics* / Q000378:metabolism*; D002687:Chitin Synthase / Q000378:metabolism*; D011992:Endosomes / Q000378:metabolism; D005656:Fungal Proteins / Q000378:metabolism*; D015966:Gene Expression Regulation, Fungal; D008565:Membrane Proteins / Q000235:genetics* / Q000378:metabolism*; D009154:Mutation / Q000502:physiology; D021381:Protein Transport / Q000502:physiology; D050765:Qa-SNARE Proteins; D012441:Saccharomyces cerevisiae; D022142:Secretory Vesicles / Q000378:metabolism; D021601:trans-Golgi Network / Q000378:metabolism*
D033942:Adaptor Proteins, Vesicular Transport; D002352:Carrier Proteins; D005656:Fungal Proteins; D008565:Membrane Proteins; D050765:Qa-SNARE Proteins; D002687:Chitin Synthase