title: Structural characterization of coatomer in its cytosolic state.
abstract: Studies on coat protein I (COPI) have contributed to a basic understanding of how coat proteins generate vesicles to initiate intracellular transport. The core component of the COPI complex is coatomer, which is a multimeric complex that needs to be recruited from the cytosol to membrane in order to function in membrane bending and cargo sorting. Previous structural studies on the clathrin adaptors have found that membrane recruitment induces a large conformational change in promoting their role in cargo sorting. Here, pursuing negative-stain electron microscopy coupled with single-particle analyses, and also performing CXMS (chemical cross-linking coupled with mass spectrometry) for validation, we have reconstructed the structure of coatomer in its soluble form. When compared to the previously elucidated structure of coatomer in its membrane-bound form we do not observe a large conformational change. Thus, the result uncovers a key difference between how COPI versus clathrin coats are regulated by membrane recruitment.
authors.affiliation: National Key Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China.|University of Chinese Academy of Sciences, Beijing, 100049, China.
authors.forename: Shengliu
authors.initials: S
authors.lastname: Wang
authors.affiliation: National Key Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China.
authors.forename: Yujia
authors.initials: Y
authors.lastname: Zhai
authors.affiliation: National Key Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China.
authors.forename: Xiaoyun
authors.initials: X
authors.lastname: Pang
authors.affiliation: National Key Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China.|University of Chinese Academy of Sciences, Beijing, 100049, China.
authors.forename: Tongxin
authors.initials: T
authors.lastname: Niu
authors.affiliation: National Institute of Biological Sciences, Beijing, Beijing, 102206, China.
authors.forename: Yue-He
authors.initials: YH
authors.lastname: Ding
authors.affiliation: National Institute of Biological Sciences, Beijing, Beijing, 102206, China.
authors.forename: Meng-Qiu
authors.initials: MQ
authors.lastname: Dong
authors.affiliation: Department of Medicine, Harvard Medical School, Brigham and Women's Hospital, Boston, MA, 02115, USA.
authors.forename: Victor W
authors.initials: VW
authors.lastname: Hsu
authors.affiliation: National Key Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China. zsun@moon.ibp.ac.cn.
authors.forename: Zhe
authors.initials: Z
authors.lastname: Sun
authors.affiliation: National Key Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China. feisun@ibp.ac.cn.|Center for Biological Imaging, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China. feisun@ibp.ac.cn.|University of Chinese Academy of Sciences, Beijing, 100049, China. feisun@ibp.ac.cn.
authors.forename: Fei
authors.identifier: 0000-0002-0351-5144
authors.initials: F
authors.lastname: Sun
mesh_terms: D020823:ADP-Ribosylation Factor 1 / Q000737:chemistry / Q000378:metabolism; D000818:Animals; D020756:Coatomer Protein / Q000737:chemistry* / Q000378:metabolism; D003600:Cytosol / Q000737:chemistry* / Q000378:metabolism; D020690:GTPase-Activating Proteins / Q000737:chemistry / Q000378:metabolism; D006801:Humans; D008567:Membranes, Artificial; D051381:Rats
chemical_list: C503239:Arfgap1 protein, rat; D020756:Coatomer Protein; D020690:GTPase-Activating Proteins; D008567:Membranes, Artificial; D020823:ADP-Ribosylation Factor 1
keywords: COPI; coatomer; human; membrane trafficking; single-particle electron microscopy