title: A novel p38 MAPK indentified from Crassostrea hongkongensis and its involvement in host response to immune challenges.
abstract: p38 mitogen-activated protein kinases (MAPKs) are conserved serine/threonine-specific kinases that are activated by various extracellular stimuli and play crucial regulatory roles in immunity, development and homeostasis. However, the function of p38s in mollusks, the second most diverse group of animals, is still poorly understood. In this study, a novel molluscan p38 (designated Chp38) was cloned and characterized from the Hong Kong oyster Crassostrea hongkongensis. Its full-length cDNA encoded a putative protein of 353 amino acids with a calculated molecular weight of approximately 40.3kDa. Similar to other reported p38 family proteins, the deduced Chp38 sequence contained a conserved dual phosphorylation TGY motif and a substrate binding site of ATRW. Phylogenetic analysis revealed that Chp38 was closest to its homolog from the Pacific oyster and belonged to the mollusk cluster. Quantitative real-time PCR analysis showed that Chp38 was constitutively expressed in all examined oyster tissues and developmental stages and that its expression in hemocytes was significantly up-regulated after pathogen (Vibrio alginolyticus and Staphylococcus haemolyticus) and PAMP (lipopolysaccharide and peptidoglycan) infections. Moreover, overexpression analysis revealed that Chp38 was localized in both the cytoplasm and nucleus of HEK293T cells and that it could significantly enhance AP-1 reporter gene activation in a dose-dependent manner. Altogether, these results provide the first experimental evidence of a functional p38 in oysters and suggest its involvement in the innate immunity of C. hongkongensis.
authors: CAS Key Laboratory of Tropical Marine Bio-Resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301,China; South China Sea Bio-Resource Exploitation and Utilization Collaborative Innovation Center, Guangzhou 510275, China; Department of Biological and Environmental Engineering, Changsha University, Changsha 410022, China.
authors: Fufa
authors: F
authors: Qu
authors: CAS Key Laboratory of Tropical Marine Bio-Resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301,China; South China Sea Bio-Resource Exploitation and Utilization Collaborative Innovation Center, Guangzhou 510275, China. Electronic address: zhimingxiang@scsio.ac.cn.
authors: Zhiming
authors: Z
authors: Xiang
authors: CAS Key Laboratory of Tropical Marine Bio-Resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301,China; South China Sea Bio-Resource Exploitation and Utilization Collaborative Innovation Center, Guangzhou 510275, China.
authors: Yang
authors: Y
authors: Zhang
authors: CAS Key Laboratory of Tropical Marine Bio-Resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301,China; South China Sea Bio-Resource Exploitation and Utilization Collaborative Innovation Center, Guangzhou 510275, China.
authors: Jun
authors: J
authors: Li
authors: CAS Key Laboratory of Tropical Marine Bio-Resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301,China; South China Sea Bio-Resource Exploitation and Utilization Collaborative Innovation Center, Guangzhou 510275, China.
authors: Shu
authors: S
authors: Xiao
authors: CAS Key Laboratory of Tropical Marine Bio-Resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301,China; South China Sea Bio-Resource Exploitation and Utilization Collaborative Innovation Center, Guangzhou 510275, China.
authors: Yuehuan
authors: Y
authors: Zhang
authors: CAS Key Laboratory of Tropical Marine Bio-Resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301,China; South China Sea Bio-Resource Exploitation and Utilization Collaborative Innovation Center, Guangzhou 510275, China.
authors: Fan
authors: F
authors: Mao
authors: CAS Key Laboratory of Tropical Marine Bio-Resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301,China; South China Sea Bio-Resource Exploitation and Utilization Collaborative Innovation Center, Guangzhou 510275, China.
authors: Haitao
authors: H
authors: Ma
authors: CAS Key Laboratory of Tropical Marine Bio-Resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301,China; South China Sea Bio-Resource Exploitation and Utilization Collaborative Innovation Center, Guangzhou 510275, China. Electronic address: carlzyu@scsio.ac.cn.
authors: Ziniu
authors: Z
authors: Yu
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D049896:Crassostrea / Q000235:genetics* / Q000276:immunology*; D057809:HEK293 Cells; D006801:Humans; D007113:Immunity, Innate / Q000276:immunology; D010802:Phylogeny; D060888:Real-Time Polymerase Chain Reaction; D048051:p38 Mitogen-Activated Protein Kinases / Q000235:genetics* / Q000276:immunology*
chemical_list: D048051:p38 Mitogen-Activated Protein Kinases
keywords: Characterization; Crassostrea hongkongensis; Expression profile; Innate immunity; p38 MAPK