title: Kazal-type proteinase inhibitor from disk abalone (Haliotis discus discus): molecular characterization and transcriptional response upon immune stimulation.
abstract: Proteinases and proteinase inhibitors are involved in several biological and physiological processes in all multicellular organisms. Proteinase inhibitors play a key role in regulating the activity of the respective proteinases. Among serine proteinase inhibitors, kazal-type proteinase inhibitors (KPIs) are widely found in mammals, avians, and a variety of invertebrates. In this study, we describe the identification of a kazal-type serine proteinase inhibitor (Ab-KPI) from the disk abalone, Haliotis discus discus, which is presumably involved in innate immunity. The full-length cDNA of Ab-KPI includes 600 bp nucleotides with an open reading frame (ORF) encoding a polypeptide of 143 amino acids. The deduced amino acid sequence of Ab-KPI contains a putative 17-amino acid signal peptide and two tandem kazal domains with high similarity to other kazal-type SPIs. Each kazal domain consists of reactive site (P1) residue containing a leucine (L), and a threonine (T) located in the second amino acid position after the second conserved cysteine of each domain. Temporal expression of Ab-KPI was assessed by real time quantitative PCR in hemocytes and mantle tissue following bacterial and viral hemorrhagic septicemia virus (VHSV) challenge, and tissue injury. At 6 h post-bacterial and -VHSV challenge, Ab-KPI expression in hemocytes was increased 14-fold and 4-fold, respectively, compared to control samples. The highest up-regulations upon tissue injury were shown at 9 h and 12 h in hemocytes and mantle, respectively. The transcriptional modulation of Ab-KPI following bacterial and viral challenges and tissue injury indicates that it might be involved in immune defense as well as wound healing process in abalone.
authors.affiliation: Department of Marine Life Sciences, School of Marine Biomedical Sciences, Jeju National University, Jeju Self-Governing Province 690-756, Republic of Korea.
authors.forename: W D Niroshana
authors.initials: WD
authors.lastname: Wickramaarachchi
authors.forename: Mahanama
authors.initials: M
authors.lastname: De Zoysa
authors.forename: Ilson
authors.initials: I
authors.lastname: Whang
authors.forename: Qiang
authors.initials: Q
authors.lastname: Wan
authors.forename: Jehee
authors.initials: J
authors.lastname: Lee
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D005786:Gene Expression Regulation / Q000276:immunology; D054884:Host-Pathogen Interactions; D008969:Molecular Sequence Data; D008974:Mollusca / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D015842:Serine Proteinase Inhibitors / Q000235:genetics / Q000378:metabolism*; D014733:Vibrio / Q000502:physiology
chemical_list: D015842:Serine Proteinase Inhibitors
keywords: Disk abalone; Immune challenges; Kazal-type proteinase inhibitor; Tissue injury; Transcriptional modulation