3uc9

Publication Abstract from PubMed

Clathrin coat accessory proteins play key roles in transport mediated by clathrin-coated vesicles. Yeast Irc6p and the related mammalian p34 are putative clathrin accessory proteins that interact with clathrin adaptor complexes. Here we present evidence that Irc6p functions in clathrin-mediated traffic between the TGN and endosomes, linking clathrin adaptor complex AP-1 and the Rab GTPase Ypt31p. The crystal structure of the Irc6p N-terminal domain revealed a G protein fold most related to small G proteins of the Rab and Arf families. However, Irc6p lacks G protein signature motifs and high-affinity GTP binding. Also, mutant Irc6p lacking candidate GTP-binding residues retained function. Mammalian p34 rescued growth defects in irc6 cells indicating functional conservation, and modeling predicted a similar N-terminal fold in p34. Irc6p and p34 also contain functionally conserved C-terminal regions. Irc6p/p34-related proteins with the same two-part architecture are encoded in genomes of species as diverse as plants and humans. Together these results define Irc6p/p34 as a novel type of conserved clathrin accessory protein and founding members of a new G protein-like family.

Yeast Irc6p is a novel type of conserved clathrin coat accessory factor related to small G proteins.,Gorynia S, Lorenz TC, Costaguta G, Daboussi L, Cascio D, Payne GS Mol Biol Cell. 2012 Sep 19. PMID:22993212^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.