title: A novel molluscan Fos gene with immune defense function identified in the Hong Kong oyster, Crassostrea hongkongensis.
abstract: The transcription factor Fos is a member of one of the best-studied AP-1 sub-families and has been implicated in a wide variety of biological processes, including the regulation of apoptosis, immune responses and cytokine production. In this report, a novel mollusk Fos (referred to as ChFos) gene was cloned and characterized from the Hong Kong oyster, Crassostrea hongkongensis. The deduced ChFos protein sequence comprised 333 amino acids and shared significant homology with invertebrate homologs. Phylogenetic analysis revealed that ChFos clusters with Fos from Crassostrea gigas and Crassostrea ariakensis. Quantitative real-time PCR analysis revealed that ChFos mRNA was broadly expressed in all tested tissues and during different stages of the oyster's embryonic and larval development. In addition, the expression of ChFos mRNA was significantly up-regulated under challenge with microorganisms (Vibrio alginolyticus, Staphylococcus haemolyticus and Saccharomyces cerevisiae) and pathogen-associated molecular patterns (PAMPs: LPS, PGN and polyI:C). Moreover, fluorescence microscopy showed that ChFos protein is localized in the nucleus in HEK293T cells. Reporter assays suggested that ChFos may act as an efficient transcription activator in the regulation of AP-1-responsive gene expression through interaction with ChJun. Overall, this study presents the first experimental evidence of the presence and functional characteristics of Fos in mollusks, which reveals its involvement in host protection against immune challenge in the oyster.
authors.affiliation: Key Laboratory of Tropical Marine Bio-resources and Ecology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou 510301, China; University of Chinese Academy of Sciences, 19A Yuquan Road, Beijing 100049, China.
authors.forename: Fufa
authors.initials: F
authors.lastname: Qu
authors.affiliation: Key Laboratory of Tropical Marine Bio-resources and Ecology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou 510301, China.
authors.forename: Zhiming
authors.initials: Z
authors.lastname: Xiang
authors.affiliation: Key Laboratory of Tropical Marine Bio-resources and Ecology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou 510301, China; University of Chinese Academy of Sciences, 19A Yuquan Road, Beijing 100049, China.
authors.forename: Fuxuan
authors.initials: F
authors.lastname: Wang
authors.affiliation: Key Laboratory of Tropical Marine Bio-resources and Ecology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou 510301, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Tropical Marine Bio-resources and Ecology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou 510301, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Tong
authors.affiliation: Key Laboratory of Tropical Marine Bio-resources and Ecology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou 510301, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Li
authors.affiliation: Key Laboratory of Tropical Marine Bio-resources and Ecology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou 510301, China.
authors.forename: Yuehuan
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Tropical Marine Bio-resources and Ecology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou 510301, China. Electronic address: carlzyu@scsio.ac.cn.
authors.forename: Ziniu
authors.initials: Z
authors.lastname: Yu
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002467:Cell Nucleus / Q000378:metabolism*; D003001:Cloning, Molecular; D049896:Crassostrea / Q000276:immunology*; D018507:Gene Expression Regulation, Developmental; D057809:HEK293 Cells; D006801:Humans; D007109:Immunity; D007239:Infections / Q000276:immunology*; D008969:Molecular Sequence Data; D016761:Oncogene Proteins v-fos / Q000235:genetics / Q000378:metabolism*; D010802:Phylogeny; D012441:Saccharomyces cerevisiae / Q000276:immunology*; D017386:Sequence Homology, Amino Acid; D041162:Staphylococcus haemolyticus / Q000276:immunology*; D059467:Transcriptome; D015854:Up-Regulation; D014733:Vibrio / Q000276:immunology*
chemical_list: D016761:Oncogene Proteins v-fos
keywords: AP-1 pathway; C. hongkongensis; Fos; Innate immunity