title: Post-Golgi anterograde transport requires GARP-dependent endosome-to-TGN retrograde transport.
abstract: The importance of endosome-to-trans-Golgi network (TGN) retrograde transport in the anterograde transport of proteins is unclear. In this study, genome-wide screening of the factors necessary for efficient anterograde protein transport in human haploid cells identified subunits of the Golgi-associated retrograde protein (GARP) complex, a tethering factor involved in endosome-to-TGN transport. Knockout (KO) of each of the four GARP subunits, VPS51-VPS54, in HEK293 cells caused severely defective anterograde transport of both glycosylphosphatidylinositol (GPI)-anchored and transmembrane proteins from the TGN. Overexpression of VAMP4, v-SNARE, in VPS54-KO cells partially restored not only endosome-to-TGN retrograde transport, but also anterograde transport of both GPI-anchored and transmembrane proteins. Further screening for genes whose overexpression normalized the VPS54-KO phenotype identified TMEM87A, encoding an uncharacterized Golgi-resident membrane protein. Overexpression of TMEM87A or its close homologue TMEM87B in VPS54-KO cells partially restored endosome-to-TGN retrograde transport and anterograde transport. Therefore GARP- and VAMP4-dependent endosome-to-TGN retrograde transport is required for recycling of molecules critical for efficient post-Golgi anterograde transport of cell-surface integral membrane proteins. In addition, TMEM87A and TMEM87B are involved in endosome-to-TGN retrograde transport.
authors.affiliation: Research Institute for Microbial Diseases, Osaka University, Osaka 565-0871, Japan WPI Immunology Frontier Research Center, Osaka University, Osaka 565-0871, Japan.
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Hirata
authors.affiliation: Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu 214122, China.
authors.forename: Morihisa
authors.initials: M
authors.lastname: Fujita
authors.affiliation: Research Institute for Microbial Diseases, Osaka University, Osaka 565-0871, Japan.
authors.forename: Shota
authors.initials: S
authors.lastname: Nakamura
authors.affiliation: Research Institute for Microbial Diseases, Osaka University, Osaka 565-0871, Japan.
authors.forename: Kazuyoshi
authors.initials: K
authors.lastname: Gotoh
authors.affiliation: Research Institute for Microbial Diseases, Osaka University, Osaka 565-0871, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Motooka
authors.affiliation: Research Institute for Microbial Diseases, Osaka University, Osaka 565-0871, Japan WPI Immunology Frontier Research Center, Osaka University, Osaka 565-0871, Japan.
authors.forename: Yoshiko
authors.initials: Y
authors.lastname: Murakami
authors.affiliation: Research Institute for Microbial Diseases, Osaka University, Osaka 565-0871, Japan WPI Immunology Frontier Research Center, Osaka University, Osaka 565-0871, Japan.
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Maeda
authors.affiliation: Research Institute for Microbial Diseases, Osaka University, Osaka 565-0871, Japan WPI Immunology Frontier Research Center, Osaka University, Osaka 565-0871, Japan tkinoshi@biken.osaka-u.ac.jp fujita@jiangnan.edu.cn.
authors.forename: Taroh
authors.initials: T
authors.lastname: Kinoshita
mesh_terms: D001692:Biological Transport; D018929:Cell Culture Techniques; D011992:Endosomes / Q000378:metabolism*; D058851:GPI-Linked Proteins / Q000378:metabolism; D055786:Gene Knockout Techniques; D017261:Glycosylphosphatidylinositols / Q000378:metabolism; D006056:Golgi Apparatus / Q000378:metabolism*; D057809:HEK293 Cells; D006367:HeLa Cells; D006801:Humans; D008565:Membrane Proteins / Q000378:metabolism*; D021381:Protein Transport; D034622:RNA Interference; D050600:SNARE Proteins / Q000378:metabolism; D033921:Vesicular Transport Proteins / Q000235:genetics / Q000378:metabolism*; D021601:trans-Golgi Network / Q000378:metabolism*
chemical_list: D058851:GPI-Linked Proteins; D017261:Glycosylphosphatidylinositols; C087215:LRRC32 protein, human; D008565:Membrane Proteins; D050600:SNARE Proteins; C555023:VPS51 protein, human; C115740:VPS52 protein, human; C486749:VPS54 protein, human; D033921:Vesicular Transport Proteins