Molecular genomic- and transcriptional-aspects of a teleost TRAF6 homolog: Possible involvement in immune responses of Oplegnathus fasciatus against pathogens. Issue 1 (January 2015)

• Record Type: Journal Article
• Authors: Umasuthan, Navaneethaiyer; Bathige, S.D.N.K.; Revathy, Kasthuri Saranya; Nam, Bo-Hye; Choi, Cheol Young; Lee, Jehee
• Is Part Of: Fish & shellfish immunology. Volume 42:Issue 1(2015:Jan.)
• Page Start: 66
• Page End: 78
• Publication Date: 2015-01
• Subjects: Fishes -- Immunology -- Periodicals; Shellfish -- Immunology -- Periodicals; Poissons -- Immunologie -- Périodiques; Crustacés -- Immunologie -- Périodiques; 571.9617
• DOI: 10.1016/j.fsi.2014.10.022
• Languages: English
• ISSNs: 1050-4648

Abstract

<abstract xml:lang="en" abstract-type="author" id="abs0010"> <title id="sectitle0010">Abstract</title> <sec> <p id="abspara0010">Tumor necrosis factor receptor (TNFR)-associated factor 6 (TRAF6) is a crucial docking molecule for TNFR superfamily and Interleukin-1 receptor/Toll-like receptor (IL-1R/TLR) superfamily. As an adaptor protein in pathogen-induced signaling cascades, TRAF6 modulates both adaptive- and innate-immunity. In order to understand the immune responses of teleost <italic>TRAF6</italic>, <italic>Oplegnathus fasciatus TRAF6-like</italic> gene (<italic>OfTRAF6</italic>) was identified and characterized. Genomic length of <italic>OfTRAF6</italic> (4 kb), obtained by means of a genomic BAC library, spanned seven exons which represented a putative coding sequence of 1716 bp and encoded 571 amino acids (aa) with an estimated molecular weight of 64 kDa. This putative protein demonstrated the classical tetra-domain architecture composed of a zinc finger RING-type profile, two zinc finger TRAF-type profiles, a coiled-coil region and a MATH domain. While the sequence similarity with human TRAF6 was 66.5%, OfTRAF6 shared a higher overall similarity with teleost homologs (∼75–92%). Phylogeny of TRAF-family was examined and TRAF6-subfamily appeared to be the precursor of other subfamilies. In addition, the clustering pattern confirmed that OfTRAF6 is a novel member of TRAF6subfamily. Based on comparative genomic analysis, we found that vertebrate <italic>TRAF6</italic> exhibits two distinct structures in teleost and tetrapod lineages. An intron-loss event has probably occurred in <italic>TRAF6</italic> gene during the evolution of tetrapods from teleosts. Inspection of putative <italic>OfTRAF6</italic> promoter revealed the presence of several immune responsive transcription factor binding sites. Real-time qPCR assay detected <italic>OfTRAF6</italic> transcripts in eleven juvenile fish tissues with higher levels in peripheral blood cells followed by liver. Putative role of <italic>OfTRAF6</italic> in response to flagellin, LPS, poly I:C, pathogenic bacteria (<italic>Edwardsiella tarda</italic> and <italic>Streptococcus iniae</italic>) and rock bream iridovirus (RBIV) was profiled in different tissues and <italic>OfTRAF6</italic> revealed up-regulated transcript levels. Altogether, these findings implicate that <italic>OfTRAF6</italic> is not only involved in flagellin-induced signaling cascade, but also contributes to the antibacterial- and antiviral-responses.</p> </sec> </abstract>