The AP-3 adaptor complex is essential for cargo-selective transport to the yeast vacuole.
Three distinct adaptor protein (AP) complexes involved in protein trafficking have been identified. AP-1 and AP-2 mediate protein sorting at the trans-Golgi network and plasma membrane, respectively, whereas the function of AP-3 has not been defined. A screen for factors specifically involved in transport of alkaline phosphatase (ALP) from the Golgi to the vacuole/lysosome has identified Ap16p and Ap15p of the yeast AP-3 complex. Deletion of each of the four AP-3 subunits results in selective mislocalization of ALP and the vacuolar t-SNARE, Vam3p (but not CPS and CPY), while deletion of AP-1 and AP-2 subunits has no effect on vacuolar protein delivery. This study, therefore, provides evidence that the AP-3 complex functions in cargo-selective protein transport from the Golgi to the vacuole/lysosome.
Cowles
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CR
Division of Cellular and Molecular Medicine and Howard Hughes Medical Institute, University of California, San Diego 92093-0668, USA.
Odorizzi
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Payne
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GS
Emr
S D
SD
D033965:Adaptor Protein Complex alpha Subunits; D033942:Adaptor Proteins, Vesicular Transport; D000469:Alkaline Phosphatase / Q000235:genetics / Q000378:metabolism*; D001692:Biological Transport; D002268:Carboxypeptidases / Q000378:metabolism; D043402:Cathepsin A; D004152:Dipeptidyl-Peptidases and Tripeptidyl-Peptidases / Q000235:genetics / Q000378:metabolism; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D006056:Golgi Apparatus / Q000201:enzymology; D008247:Lysosomes / Q000201:enzymology; D008565:Membrane Proteins / Q000378:metabolism / Q000502:physiology; D034041:Monomeric Clathrin Assembly Proteins; D050765:Qa-SNARE Proteins; D011993:Recombinant Fusion Proteins; D012441:Saccharomyces cerevisiae / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins; D017384:Sequence Deletion; D014617:Vacuoles / Q000201:enzymology*
D033965:Adaptor Protein Complex alpha Subunits; D033942:Adaptor Proteins, Vesicular Transport; D005656:Fungal Proteins; D008565:Membrane Proteins; D034041:Monomeric Clathrin Assembly Proteins; C081224:PEP12 protein, S cerevisiae; D050765:Qa-SNARE Proteins; D011993:Recombinant Fusion Proteins; D029701:Saccharomyces cerevisiae Proteins; C107706:VAM3 protein, S cerevisiae; C439023:clathrin assembly protein AP180; D000469:Alkaline Phosphatase; D002268:Carboxypeptidases; D004152:Dipeptidyl-Peptidases and Tripeptidyl-Peptidases; C061833:STE13 protein, S cerevisiae; D043402:Cathepsin A; C019836:CPS1 protein, S cerevisiae