Calmodulin of the tropical sea cucumber: Gene structure, inducible expression and contribution to nitric oxide production and pathogen clearance during immune response.
Calmodulin (CaM) is an essential second messenger protein that transduces calcium signals by binding calcium ions (Ca(2+)) and modulating its interactions with various target proteins. In contrast to vertebrates, where CaM is well established as a cofactor for Ca(2+)-dependent physiological and cellular functions including host defense, there is a paucity of understanding on CaM in invertebrates (such as echinoderms) in response to immune challenge or microbial infections. In this study, we obtained and described the gene sequence of CaM from the tropical sea cucumber Stichopus monotuberculatus, a promising yet poorly characterized aquacultural species. mRNA expression of StmCaM could be detected in the intestine and coelomic fluid after Vibrio alginolyticus injection. Transcriptional and translational expression of StmCaM was inducible in nature, as evidenced by the expression patterns in primary coelomocytes following Vibrio challenge. This response could be mimicked by the Vibrio cells membrane components or lipopolysaccharides (LPS), and blocked by co-treatment of the LPS-neutralizing agent polymyxin B (PMB). Furthermore, inhibition of CaM activity by incubation with its inhibitor trifluoroperazine dihydrochloride (TFP) blunted the production of Vibrio-induced nitric oxide (NO) and augmented the survival of invading Vibrio in coelomocytes. Collectively, our study here supplied the first evidence for echinoderm CaM participation in innate immunity, and provided a functional link between CaM expression and antibacterial NO production in sea cucumber.
CAS Key Laboratory of Tropical Marine Bio-resources and Ecology (LMB), Key Laboratory of Applied Marine Biology of Guangdong Province and Chinese Academy of Sciences (LAMB), South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China. Electronic address: chan1010@scsio.ac.cn.
Ting
T
Chen
CAS Key Laboratory of Tropical Marine Bio-resources and Ecology (LMB), Key Laboratory of Applied Marine Biology of Guangdong Province and Chinese Academy of Sciences (LAMB), South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China. Electronic address: rosemary166@sina.com.
Chunhua
C
Ren
CAS Key Laboratory of Tropical Marine Bio-resources and Ecology (LMB), Key Laboratory of Applied Marine Biology of Guangdong Province and Chinese Academy of Sciences (LAMB), South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China; University of Chinese Academy of Sciences, Beijing, China. Electronic address: liwuhusunny@163.com.
Wuhu
W
Li
CAS Key Laboratory of Tropical Marine Bio-resources and Ecology (LMB), Key Laboratory of Applied Marine Biology of Guangdong Province and Chinese Academy of Sciences (LAMB), South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China. Electronic address: jiangxiao4367@126.com.
Xiao
X
Jiang
CAS Key Laboratory of Tropical Marine Bio-resources and Ecology (LMB), Key Laboratory of Applied Marine Biology of Guangdong Province and Chinese Academy of Sciences (LAMB), South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China. Electronic address: jianjunxia@scsio.ac.cn.
Jianjun
J
Xia
Department of Chemistry, University of Hong Kong, Hong Kong, China. Electronic address: wongnk@gmail.com.
Nai-Kei
NK
Wong
CAS Key Laboratory of Tropical Marine Bio-resources and Ecology (LMB), Key Laboratory of Applied Marine Biology of Guangdong Province and Chinese Academy of Sciences (LAMB), South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China. Electronic address: hucq@scsio.ac.cn.
Chaoqun
C
Hu
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002147:Calmodulin / Q000235:genetics* / Q000378:metabolism; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics / Q000378:metabolism; D007113:Immunity, Innate; D008969:Molecular Sequence Data; D009569:Nitric Oxide / Q000378:metabolism; D009928:Organ Specificity; D010802:Phylogeny; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction / Q000662:veterinary; D016415:Sequence Alignment; D047528:Stichopus / Q000235:genetics* / Q000276:immunology* / Q000378:metabolism; D044149:Vibrio alginolyticus / Q000502:physiology
D002147:Calmodulin; D018076:DNA, Complementary; D012333:RNA, Messenger; D009569:Nitric Oxide
Calmodulin; Gene structure; Invertebrate innate immunity; Nitric oxide; Stichopus monotuberculatus; Vibrio