Calmodulin of the tropical sea cucumber: Gene structure, inducible expression and contribution to nitric oxide production and pathogen clearance during immune response. Issue 2 (August 2015)

• Record Type: Journal Article
• Authors: Chen, Ting; Ren, Chunhua; Li, Wuhu; Jiang, Xiao; Xia, Jianjun; Wong, Nai-Kei; Hu, Chaoqun
• Is Part Of: Fish & shellfish immunology. Volume 45:Issue 2(2015:Aug.)
• Page Start: 231
• Page End: 238
• Publication Date: 2015-08
• Subjects: Fishes -- Immunology -- Periodicals; Shellfish -- Immunology -- Periodicals; Poissons -- Immunologie -- Périodiques; Crustacés -- Immunologie -- Périodiques; 571.9617
• DOI: 10.1016/j.fsi.2015.04.013
• Languages: English
• ISSNs: 1050-4648

Abstract

<abstract xml:lang="en" abstract-type="author" id="abs0010"> <title id="sectitle0010">Abstract</title> <sec> <p id="abspara0010">Calmodulin (CaM) is an essential second messenger protein that transduces calcium signals by binding calcium ions (Ca<sup>2+</sup>) and modulating its interactions with various target proteins. In contrast to vertebrates, where CaM is well established as a cofactor for Ca<sup>2+</sup>-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 <italic>CaM</italic> from the tropical sea cucumber <italic>Stichopus monotuberculatus</italic>, a promising yet poorly characterized aquacultural species. mRNA expression of <italic>StmCaM</italic> could be detected in the intestine and coelomic fluid after <italic>Vibrio alginolyticus</italic> injection. Transcriptional and translational expression of <italic>Stm</italic>CaM was inducible in nature, as evidenced by the expression patterns in primary coelomocytes following <italic>Vibrio</italic> challenge. This response could be mimicked by the <italic>Vibrio</italic> 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 <italic>Vibrio</italic>-induced nitric oxide (NO) and augmented the survival of invading <italic>Vibrio</italic> 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.</p> </sec> </abstract>