Functional genomic studies on an immune- and antiviral-related gene of MyD88 in orange-spotted grouper, Epinephelus coioides

Abstract

Myeloid differentiation factor 88 (MyD88) is a universal adaptor protein involved in Toll-like receptors and in interleukin-1 receptor-induced nuclear factor-kappaB (NF-κB) activation. In this study, a new MyD88 gene (designated as Og-MyD88) was cloned from orange-spotted grouper, Epinephelus coioides, based on the expressed sequence tag (EST) obtained following Roche 454 GS-FLX™ sequencing. The full-length Og-MyD88 cDNA is composed of 1682 bp and encodes a deduced polypeptide of 289 amino acids with 86% homology to MyD88 of Siniperca chuatsi. The deduced amino acid sequence of Og-MyD88 contains a typical death domain at the amino terminus and a conserved Toll/IL-1R (TIR) domain at the carboxyl terminus, as well as three highly conserved motifs (Box1, Box2 and Box3) within the C-terminal TIR domain. In healthy fish, Og-MyD88 was found to be strongly expressed in immune-related tissues, including the spleen, head kidney, kidney, liver, skin and intestine, with lower expression in heart, stomach, brain and muscle. Transcripts of Og-MyD88 were found to be markedly up-regulated in fish spleen after challenge with Singapore grouper iridovirus (SGIV), a highly lethal viral pathogen to grouper fish. Furthermore, the full length Og-MyD88 and its N-terminal death domain were capable of inducing NF-κB activity in HEK-293 cells. Overexpressed Og-MyD88 showed the ability to inhibit replication of SGIV in grouper spleen (GS) cells. These results suggest that Og-MyD88 is involved in the grouper immune response to invasion of viral pathogens and may share similar functions to those observed in higher vertebrates.

Molecular cloning and expression studies of the adapter molecule myeloid differentiation factor 88 (MyD88) in turbot (Scophthalmus maximus)

“…2 C3). These results are in agreement with the findings for MyD88s from grass carp and orangespotted grouper with virus challenge (Su et al, 2011;Yan et al, 2012). In contrast, the two synthetic immunostimulants induced higher levels of SmMyD88 transcripts in the head kidney.…”

“…To date, MyD88 has been identified in mammals, birds, reptiles, amphibians, fishes and invertebrates (Bonnert et al, 1997;Deepika et al, 2014;Li et al, 2011;Prothmann et al, 2000;Wheaton et al, 2007). The fishes with MyD88 identified include zebrafish (van der Sar et al, 2006), Japanese flounder (Takano et al, 2006), half-smooth tongue sole (Yu et al, 2009), large yellow croaker (Yao et al, 2009), Atlantic salmon (Skjaeveland et al, 2009), rainbow trout (Rebl et al, 2009), rock bream (Whang et al, 2011), common carp (Kongchum et al, 2011), grass carp (Su et al, 2011), orange-spotted grouper (Yan et al, 2012), miiuy croaker (Tang et al, 2012), etc. Fish MyD88 exhibits structural and functional homologies with its mammalian counterpart.…”

Blunt Snout Bream (Megalobrama amblycephala) MyD88 and TRAF6: Characterisation, Comparative Homology Modelling and Expression

“…Based on the instability index (II) value, which is a measure to evaluate the stability of proteins in a test tube, Ma MyD88 protein (II = 33.5) is probably stable (II < 40), while Ma TRAF6 (II = 58.6) is probably not stable (II > 40) [ 27 ]. High AI (aliphatic index) value of Ma MyD88 (87.18) and Ma TRAF6 (72.14) indicate high thermostability of these proteins [ 28 ]. Low grand average hydropathicity (GRAVY) values of both proteins imply they are hydrophilic in natural conditions.…”

Omics in marine biotechnology

“…This topic contains 12 papers produced by research groups from China, Germany, and Korea. To help readers, we have arranged the papers according to their research topics: genomics [1-3]; transcriptomics [4]; proteomics [5][6][7][8][9]; metabolomics [10,11], and nutrigenomics [12].The objective of this topic is to offer a platform for marine biological scientists to present recent advances in the discovery and development of omics in marine biotechnology, providing a large-scale, holistic approach to understanding life in encapsulated "omes". In this special topic, several genomes, including major histocompatibility complex genes [2], phytochrome genes [3] and immune-and antiviral-related genes [4], have been systematically investigated based on functional genomic studies, providing targets for further structural and functional analyses.…”

“…This topic contains 12 papers produced by research groups from China, Germany, and Korea. To help readers, we have arranged the papers according to their research topics: genomics [1-3]; transcriptomics [4]; proteomics [5][6][7][8][9]; metabolomics [10,11], and nutrigenomics [12].…”