title: Molecular characterization, phylogeny, and expression pattern of c-type lysozyme in kelp grouper, Epinephelus bruneus.
abstract: Lysozymes are the key molecules in innate immune system and possess high bactericidal properties. In the present study, a full-length c-type lysozyme cDNA has been cloned and characterized by expressed sequence tag (EST) and rapid amplification of cDNA ends (RACE) techniques from kelp grouper, Epinephelus bruneus (Eb-CTL). The cDNA consists of 753 base pairs (bp) with a 432 bp open reading frame (ORF) that encodes 144 amino acids (aa) residues and polyadenylation signal sequence AATAAA. The deduced aa sequence polypeptide had a predicted molecular weight of 16 kDa and theoretical isoelectric point of 7.3. The deduced aa sequence have a long lysozyme domain which contains all catalytic sites and other conserved residues required for lysozyme activity. Pair-wise alignments showed a higher identity (76.4%) with Psetta maxima lysozyme and low identity (38.9%) with lysozymes of insect Bombyx mori. Interestingly, phylogenetic analysis revealed that the kelp grouper lysozyme was more closely related to other fish and vertebrate lysozymes. Quantitative real-time reverse transcriptase-PCR analysis showed that Eb-CTL transcripts are constitutively expressed in hematopoietic organs such as heart, spleen, and kidney after stimulation with LPS or infection with Vibrio anguillarum, indicating the involvement of Eb-CTL in the innate immunity of kelp grouper. This study is a first step on the genetics and functions of the c-type lysozyme in kelp grouper, and their role in anti-bacterial activity with reference to immunological properties which might have biotechnological applications.
authors.affiliation: Marine Applied Microbes and Aquatic Organism Disease Control Lab, Department of Aquatic Biomedical Sciences, School of Marine Biomedical Sciences, College of Ocean Sciences & Marine and Environmental Research Institute, Jeju National University, Jeju 690-756, South Korea. rhari123@yahoo.com
authors.forename: Ramasamy
authors.initials: R
authors.lastname: Harikrishnan
authors.forename: Ju-Sang
authors.initials: JS
authors.lastname: Kim
authors.forename: Man-Chul
authors.initials: MC
authors.lastname: Kim
authors.forename: Chellam
authors.initials: C
authors.lastname: Balasundaram
authors.forename: Moon-Soo
authors.initials: MS
authors.lastname: Heo
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D005393:Fish Diseases / Q000276:immunology; D015971:Gene Expression Regulation, Enzymologic; D007113:Immunity, Innate; D008969:Molecular Sequence Data; D009113:Muramidase / Q000737:chemistry / Q000235:genetics* / Q000276:immunology*; D016366:Open Reading Frames; D010473:Perciformes / Q000235:genetics* / Q000382:microbiology; D010802:Phylogeny; D011897:Random Allocation; D060888:Real-Time Polymerase Chain Reaction / Q000662:veterinary; D056910:Republic of Korea; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000662:veterinary; D014733:Vibrio / Q000502:physiology; D014735:Vibrio Infections / Q000276:immunology / Q000662:veterinary
chemical_list: D018076:DNA, Complementary; D009113:Muramidase