title: Characterization of YIPF3 and YIPF4, cis-Golgi Localizing Yip domain family proteins.
abstract: The Yip1 domain family (YIPF) proteins are homologues of yeast Yip1p and Yif1p, which are proposed to function in ER to Golgi transport. Here, we report the characterization of YIPF3 and YIPF4, homologues of human Yif1p and Yip1p, respectively. Immunofluorescence and immuno-electron microscopy showed that both YIPF3 and YIPF4 are clearly concentrated in the cis-Golgi. While YIPF4 was detected as a single mobility form consistent with its predicted molecular weight, three different mobility forms of YIPF3 were detected by western blotting. Biochemical and immunofluorescence experiments strongly indicated that YIPF3 is synthesized in the ER as a N-glycosylated form (40 kDa), is then O-glycosylated in the Golgi apparatus to become a lower mobility form (46 kDa) and finally becomes a higher mobility form cleaved at its C-terminal luminal domain (36 kDa). YIPF3 and YIPF4 form a complex in the Golgi apparatus, and this was suggested to be important for their proper localization and function. The knockdown of YIPF3 or YIPF4 in HeLa cells induced fragmentation of the Golgi apparatus, suggesting their involvement in the maintenance of the Golgi structure.
authors.affiliation: Graduate School of Natural Science and Technology and School of Pharmacy, Kanazawa University, Japan.
authors.forename: Kouji
authors.initials: K
authors.lastname: Tanimoto
authors.forename: Kurumi
authors.initials: K
authors.lastname: Suzuki
authors.forename: Eija
authors.initials: E
authors.lastname: Jokitalo
authors.forename: Noriko
authors.initials: N
authors.lastname: Sakai
authors.forename: Tomoaki
authors.initials: T
authors.lastname: Sakaguchi
authors.forename: Daisuke
authors.initials: D
authors.lastname: Tamura
authors.forename: Gourou
authors.initials: G
authors.lastname: Fujii
authors.forename: Kenji
authors.initials: K
authors.lastname: Aoki
authors.forename: Saya
authors.initials: S
authors.lastname: Takada
authors.forename: Ryuichi
authors.initials: R
authors.lastname: Ishida
authors.forename: Masako
authors.initials: M
authors.lastname: Tanabe
authors.forename: Hideaki
authors.initials: H
authors.lastname: Itoh
authors.forename: Yukio
authors.initials: Y
authors.lastname: Yoneda
authors.forename: Miwa
authors.initials: M
authors.lastname: Sohda
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Misumi
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Nakamura
mesh_terms: D033942:Adaptor Proteins, Vesicular Transport; D000595:Amino Acid Sequence; D004721:Endoplasmic Reticulum / Q000737:chemistry / Q000378:metabolism; D006031:Glycosylation; D006056:Golgi Apparatus / Q000737:chemistry / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D008565:Membrane Proteins / Q000235:genetics* / Q000378:metabolism*; D008969:Molecular Sequence Data; D009154:Mutation; D017434:Protein Structure, Tertiary; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000378:metabolism; D011994:Recombinant Proteins / Q000032:analysis / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000378:metabolism
chemical_list: D033942:Adaptor Proteins, Vesicular Transport; D008565:Membrane Proteins; D034741:RNA, Small Interfering; D011994:Recombinant Proteins; D029701:Saccharomyces cerevisiae Proteins; C473803:YIF1 protein, S cerevisiae; C478651:YIPF3 protein, human; C568918:YIPF4 protein, human