title: Structural and functional characterization of a novel molluskan ortholog of TRAF and TNF receptor-associated protein from disk abalone (Haliotis discus discus).
abstract: Immune signaling cascades have an indispensable role in the host defense of almost all the organisms. Tumor necrosis factor (TNF) signaling is considered as a prominent signaling pathway in vertebrate as well as invertebrate species. Within the signaling cascade, TNF receptor-associated factor (TRAF) and TNF receptor-associated protein (TTRAP) has been shown to have a crucial role in the modulation of immune signaling in animals. Here, we attempted to characterize a novel molluskan ortholog of TTRAP (AbTTRAP) from disk abalone (Haliotis discus discus) and analyzed its expression levels under pathogenic stress. The complete coding sequence of AbTTRAP consisted of 1071 nucleotides, coding for a 357 amino acid peptide, with a predicted molecular mass of 40 kDa. According to our in-silico analysis, AbTTRAP resembled the typical TTRAP domain architecture, including a 5'-tyrosyl DNA phosphodiesterase domain. Moreover, phylogenetic analysis revealed its common ancestral invertebrate origin, where AbTTRAP was clustered with molluskan counterparts. Quantitative real time PCR showed universally distributed expression of AbTTRAP in selected tissues of abalone, from which more prominent expression was detected in hemocytes. Upon stimulation with two pathogen-derived mitogens, lipopolysaccharide (LPS) and polyinosinic:polycytidylic acid (poly I:C), transcript levels of AbTTRAP in hemocytes and gill tissues were differentially modulated with time. In addition, the recombinant protein of AbTTRAP exhibited prominent endonuclease activity against abalone genomic DNA, which was enhanced by the presence of Mg(2+) in the medium. Collectively, these results reinforce the existence of the TNF signaling cascade in mollusks like disk abalone, further implicating the putative regulatory behavior of TTRAP in invertebrate host pathology.
authors: Korea Institute of Ocean Science & Technology, Ansan 426-744, Republic of Korea.
authors: Youngdeuk
authors: Y
authors: Lee
authors: Department of Marine Life Sciences, School of Marine Biomedical Sciences, Jeju National University, Jeju Self-Governing Province 690-756, Republic of Korea; Fish Vaccine Development Center, Jeju National University, Jeju Self-Governing Province 690-756, Republic of Korea.
authors: Don Anushka Sandaruwan
authors: DA
authors: Elvitigala
authors: Department of Marine Life Sciences, School of Marine Biomedical Sciences, Jeju National University, Jeju Self-Governing Province 690-756, Republic of Korea; Fish Vaccine Development Center, Jeju National University, Jeju Self-Governing Province 690-756, Republic of Korea. Electronic address: ilsonwhang@hanmail.net.
authors: Ilson
authors: I
authors: Whang
authors: Department of Marine Life Sciences, School of Marine Biomedical Sciences, Jeju National University, Jeju Self-Governing Province 690-756, Republic of Korea; Fish Vaccine Development Center, Jeju National University, Jeju Self-Governing Province 690-756, Republic of Korea.
authors: Sukkyoung
authors: S
authors: Lee
authors: Department of Marine Life Sciences, School of Marine Biomedical Sciences, Jeju National University, Jeju Self-Governing Province 690-756, Republic of Korea; Fish Vaccine Development Center, Jeju National University, Jeju Self-Governing Province 690-756, Republic of Korea.
authors: Hyowon
authors: H
authors: Kim
authors: College of Veterinary Medicine, Chungnam National University, Yuseong-gu, Daejeon 305-764, Republic of Korea.
authors: Mahanama De
authors: MD
authors: Zoysa
authors: Korea Institute of Ocean Science & Technology, Ansan 426-744, Republic of Korea.
authors: Chulhong
authors: C
authors: Oh
authors: Korea Institute of Ocean Science & Technology, Ansan 426-744, Republic of Korea.
authors: Do-Hyung
authors: DH
authors: Kang
authors: Department of Marine Life Sciences, School of Marine Biomedical Sciences, Jeju National University, Jeju Self-Governing Province 690-756, Republic of Korea; Fish Vaccine Development Center, Jeju National University, Jeju Self-Governing Province 690-756, Republic of Korea. Electronic address: jehee@jejunu.ac.kr.
authors: Jehee
authors: J
authors: Lee
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D004720:Endonucleases / Q000378:metabolism; D049851:Gastropoda / Q000235:genetics* / Q000378:metabolism; D005786:Gene Expression Regulation; D008070:Lipopolysaccharides; D008969:Molecular Sequence Data; D009928:Organ Specificity; D010802:Phylogeny; D011070:Poly I-C; D060888:Real-Time Polymerase Chain Reaction; D011994:Recombinant Proteins / Q000378:metabolism; D016415:Sequence Alignment; D047988:Tumor Necrosis Factor Receptor-Associated Peptides and Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism
chemical_list: D008070:Lipopolysaccharides; D011994:Recombinant Proteins; D047988:Tumor Necrosis Factor Receptor-Associated Peptides and Proteins; D004720:Endonucleases; D011070:Poly I-C
keywords: Disk abalone; Endonuclease activity; Gene ontology; TTRAP; Transcriptional analysis