title: Impairment of Cargo Transportation Caused bygbf1Mutation Disrupts Vascular Integrity and Causes Hemorrhage in Zebrafish Embryos.
abstract: ADP-ribosylation factor GTPases are activated by guanine nucleotide exchange factors including Gbf1 (Golgi brefeldin A-resistant factor 1) and play important roles in regulating organelle structure and cargo-selective vesicle trafficking. However, the developmental role of Gbf1 in vertebrates remains elusive. In this study, we report the zebrafish mutant linetsu3994that arises fromN-ethyl-N-nitrosourea (ENU)-mediated mutagenesis and is characterized by prominent intracerebral and trunk hemorrhage. The mutant embryos develop hemorrhage accompanied by fewer pigments and shorter caudal fin at day 2 of development. The hemorrhage phenotype is caused by vascular breakage in a cell autonomous fashion. Positional cloning identifies a T → G nucleotide substitution in the 23rd exon of thegbf1locus, resulting in a leucine → arginine substitution (L1246R) in the HDS2 domain. The mutant phenotype is mimicked bygbf1knockouts and morphants, suggesting a nature of loss of function. Experimental results in mammalian cells show that the mutant form Gbf1(L1246R) is unable to be recruited to the Golgi apparatus and fails to activate Arf1 for recruiting COPI complex. The hemorrhage intsu3994mutants can be prevented partially and temporally by treating with the endoplasmic reticulum stress/apoptosis inhibitor tauroursodeoxycholic acid or by knocking down the proapoptotic genebaxbTherefore, endothelial endoplasmic reticulum stress and subsequent apoptosis induced bygbf1deficiency may account for the vascular collapse and hemorrhage.
authors.affiliation: From the Laboratory of Molecular Developmental Biology, State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Chen
authors.affiliation: From the Laboratory of Molecular Developmental Biology, State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China.
authors.forename: Xiaotong
authors.initials: X
authors.lastname: Wu
authors.affiliation: From the Laboratory of Molecular Developmental Biology, State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China.
authors.forename: Likun
authors.initials: L
authors.lastname: Yao
authors.affiliation: From the Laboratory of Molecular Developmental Biology, State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China.
authors.forename: Lu
authors.initials: L
authors.lastname: Yan
authors.affiliation: From the Laboratory of Molecular Developmental Biology, State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Zhang
authors.affiliation: From the Laboratory of Molecular Developmental Biology, State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China.
authors.forename: Juhui
authors.initials: J
authors.lastname: Qiu
authors.affiliation: From the Laboratory of Molecular Developmental Biology, State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China.
authors.forename: Xingfeng
authors.initials: X
authors.lastname: Liu
authors.affiliation: From the Laboratory of Molecular Developmental Biology, State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China.
authors.forename: Shunji
authors.initials: S
authors.lastname: Jia
authors.affiliation: From the Laboratory of Molecular Developmental Biology, State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China mengam@mail.tsinghua.edu.cn.
authors.forename: Anming
authors.initials: A
authors.lastname: Meng
mesh_terms: D000818:Animals; D001808:Blood Vessels / Q000503:physiopathology*; D020755:Coat Protein Complex I / Q000378:metabolism; D006056:Golgi Apparatus / Q000378:metabolism; D020662:Guanine Nucleotide Exchange Factors / Q000235:genetics* / Q000378:metabolism; D006470:Hemorrhage / Q000209:etiology*; D009154:Mutation; D021381:Protein Transport; D015027:Zebrafish / Q000196:embryology*
chemical_list: D020755:Coat Protein Complex I; D020662:Guanine Nucleotide Exchange Factors
keywords: Golgi; embryo; protein trafficking (Golgi); vascular; zebrafish