A conserved N-terminal arginine-motif in GOLPH3-family proteins mediates binding to coatomer.
Vps74p, a member of the GOLPH3 protein family, binds directly to coatomer and the cytoplasmic tails of a subset of Golgi-resident glycosyltransferases to mediate their Golgi retention. We identify a cluster of arginine residues at the N-terminal end of GOLPH3 proteins that are necessary and sufficient to mediate coatomer binding. While loss of coatomer binding renders Vps74p non-functional for glycosyltransferase retention, the Golgi membrane-binding capabilities of the mutant protein are not significantly reduced. We establish that the oligomerization status and phosphatidylinositol-4-phosphate-binding properties of Vps74p largely account for the membrane-binding capacity of the protein and identify an Arf1p-Vps74p interaction as a potential contributing factor in Vps74p Golgi membrane association.
Division of Life Science, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, SAR of China.
Linna
L
Tu
Lu
L
Chen
David K
DK
Banfield
D020823:ADP-Ribosylation Factor 1 / Q000378:metabolism; D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D001120:Arginine / Q000378:metabolism*; D001665:Binding Sites; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D020756:Coatomer Protein / Q000378:metabolism*; D006056:Golgi Apparatus / Q000378:metabolism; D007425:Intracellular Membranes / Q000378:metabolism; D008364:Mannosyltransferases / Q000378:metabolism; D008969:Molecular Sequence Data; D009154:Mutation; D018129:Phosphatidylinositol Phosphates / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
D002352:Carrier Proteins; D020756:Coatomer Protein; D018129:Phosphatidylinositol Phosphates; D029701:Saccharomyces cerevisiae Proteins; C528905:Vps74 protein, S cerevisiae; C037178:phosphatidylinositol 4-phosphate; D001120:Arginine; C068701:KRE2 protein, S cerevisiae; D008364:Mannosyltransferases; D020823:ADP-Ribosylation Factor 1