title: Phase transition of spindle-associated protein regulate spindle apparatus assembly.
abstract: Spindle assembly required during mitosis depends on microtubule polymerization. We demonstrate that the evolutionarily conserved low-complexity protein, BuGZ, undergoes phase transition or coacervation to promote assembly of both spindles and their associated components. BuGZ forms temperature-dependent liquid droplets alone or on microtubules in physiological buffers. Coacervation in vitro or in spindle and spindle matrix depends on hydrophobic residues in BuGZ. BuGZ coacervation and its binding to microtubules and tubulin are required to promote assembly of spindle and spindle matrix in Xenopus egg extract and in mammalian cells. Since several previously identified spindle-associated components also contain low-complexity regions, we propose that coacervating proteins may be a hallmark of proteins that comprise a spindle matrix that functions to promote assembly of spindles by concentrating its building blocks.
authors.affiliation: State Key Laboratory of Cell Biology, CAS Center for Excellence in Molecular Cell Science, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, China; Department of Embryology, Carnegie Institution for Science, 3520 San Martin Drive, Baltimore, MD 21218, USA.
authors.forename: Hao
authors.initials: H
authors.lastname: Jiang
authors.affiliation: Department of Embryology, Carnegie Institution for Science, 3520 San Martin Drive, Baltimore, MD 21218, USA.
authors.forename: Shusheng
authors.initials: S
authors.lastname: Wang
authors.affiliation: Department of Embryology, Carnegie Institution for Science, 3520 San Martin Drive, Baltimore, MD 21218, USA.
authors.forename: Yuejia
authors.initials: Y
authors.lastname: Huang
authors.affiliation: State Key Laboratory of Cell Biology, CAS Center for Excellence in Molecular Cell Science, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, China.
authors.forename: Xiaonan
authors.initials: X
authors.lastname: He
authors.affiliation: Department of Chemical and Biomolecular Engineering and Institute for NanoBioTechnology, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218, USA.
authors.forename: Honggang
authors.initials: H
authors.lastname: Cui
authors.affiliation: State Key Laboratory of Cell Biology, CAS Center for Excellence in Molecular Cell Science, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, China. Electronic address: xlzhu@sibcb.ac.cn.
authors.forename: Xueliang
authors.initials: X
authors.lastname: Zhu
authors.affiliation: Department of Embryology, Carnegie Institution for Science, 3520 San Martin Drive, Baltimore, MD 21218, USA. Electronic address: zheng@ciwemb.edu.
authors.forename: Yixian
authors.initials: Y
authors.lastname: Zheng
mesh_terms: D000818:Animals; D006367:HeLa Cells; D006801:Humans; D008869:Microtubule-Associated Proteins / Q000378:metabolism*; D008870:Microtubules / Q000378:metabolism*; D008938:Mitosis; D010649:Phenylalanine / Q000378:metabolism; D008941:Spindle Apparatus / Q000378:metabolism*; D013696:Temperature; D014404:Tubulin / Q000378:metabolism; D014443:Tyrosine / Q000378:metabolism; D014981:Xenopus
chemical_list: D008869:Microtubule-Associated Proteins; D014404:Tubulin; C587673:ZNF207 protein, human; D014443:Tyrosine; D010649:Phenylalanine