title: Yip1A regulates the COPI-independent retrograde transport from the Golgi complex to the ER.
abstract: Yip1A, a mammalian homologue of yeast Yip1p, is a multi-spanning membrane protein that is considered to be involved in transport between the endoplasmic reticulum (ER) and the Golgi. However, the precise role of Yip1A in mammalian cells remains unclear. We show here that endogenous Yip1A is localized to the ER-Golgi intermediate compartment (ERGIC). Knockdown of Yip1A by RNAi did not induce morphological changes in the Golgi, ER, or ERGIC. By analyzing a number of intracellular transport pathways, we found that Yip1A knockdown delayed the transport of Shiga toxin from the Golgi to the ER, but did not affect the anterograde transport of VSVGts045. We also found that a recombinant protein that corresponded to the N-terminal domain of Yip1A inhibited the COPI-independent retrograde transport of GFP-tagged galactosyltransferase, GT-GFP, but not the COPI-dependent retrograde transport of p58/ERGIC53. Furthermore, we found that Yip1A knockdown resulted in the dissociation of Rab6 from the membranes. These results suggested that Yip1A has a role in COPI-independent retrograde transport from the Golgi to the ER and regulates the membrane recruitment of Rab6.
authors.affiliation: Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Komaba 3-8-1, Meguro-ku, Tokyo 153-8902, Japan.
authors.forename: Fumi
authors.initials: F
authors.lastname: Kano
authors.forename: Shinobu
authors.initials: S
authors.lastname: Yamauchi
authors.forename: Yumi
authors.initials: Y
authors.lastname: Yoshida
authors.forename: Miho
authors.initials: M
authors.lastname: Watanabe-Takahashi
authors.forename: Kiyotaka
authors.initials: K
authors.lastname: Nishikawa
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Nakamura
authors.forename: Masayuki
authors.initials: M
authors.lastname: Murata
mesh_terms: D000818:Animals; D001692:Biological Transport / Q000502:physiology; D002460:Cell Line; D020755:Coat Protein Complex I / Q000235:genetics / Q000378:metabolism*; D004721:Endoplasmic Reticulum / Q000378:metabolism* / Q000648:ultrastructure; D006056:Golgi Apparatus / Q000378:metabolism* / Q000648:ultrastructure; D006367:HeLa Cells; D006801:Humans; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism; D010455:Peptides / Q000235:genetics / Q000378:metabolism; D034622:RNA Interference; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D022622:Shiga Toxin 1 / Q000378:metabolism; D033921:Vesicular Transport Proteins / Q000235:genetics / Q000378:metabolism*; D014759:Viral Envelope Proteins / Q000235:genetics / Q000378:metabolism; D020691:rab GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D020755:Coat Protein Complex I; C028391:G protein, vesicular stomatitis virus; D008562:Membrane Glycoproteins; D010455:Peptides; C094135:Rab6 protein; D011993:Recombinant Fusion Proteins; D022622:Shiga Toxin 1; D033921:Vesicular Transport Proteins; D014759:Viral Envelope Proteins; C502736:YIPF5 protein, human; D020691:rab GTP-Binding Proteins