title: Molecular cloning, characterization and gene expression of murrel CXC chemokine receptor 3a against sodium nitrite acute toxicity and microbial pathogens.
abstract: CXCR3 is a CXC chemokine receptor 3 which binds to CXC ligand 4 (CXCL4), 9, 10 and 11. CXC chemokine receptor 3a (CXCR3a) is one of the splice variants of CXCR3. It plays crucial role in defense and other physiological processes. In this study, we report the molecular cloning, characterization and gene expression of CXCR3a from striped murrel Channa striatus (Cs). The full length CsCXCR3a cDNA sequence was obtained from the constructed cDNA library of striped murrel by cloning and sequencing using an internal sequencing primer. The full length sequence is 1425 nucleotides in length including an open reading frame of 1086 nucleotides which is encoded with a polypeptide of 361 amino acids (mol. wt. 40 kDa). CsCXCR3a domain analysis showed that the protein contains a G protein coupled receptor between 55 and 305 along with its family signature at 129-145. The transmembrane prediction analysis showed that CsCXCR3a protein contains 7 transmembrane helical regions at 34-65, 80-106, 113-146, 154-181, 208-242, 249-278 and 284-308. The 'DRY' motif from CsCXCR3a protein sequence at (140)Asp-(141)Arg-(142)Tyr which is responsible for G-protein binding is also highly conserved with CXCR3 from other species. Phylogenetic tree showed that the CXC chemokine receptors 3, 4, 5 and 6, each formed a separate clade, but 1 and 2 were clustered together, which may be due to the high similarity between these receptors. The predicted 3D structure revealed cysteine residues, which are responsible for 'CXC' motif at 116 and 198. The CsCXR3a transcript was found to be high in kidney, further its expression was up-regulated by sodium nitrite acute toxicity exposure, fungal, bacterial and poly I:C challenges. Overall, these results supported the active involvement of CsCXCR3a in inflammatory process of striped murrel during infection. However, further study is necessary to explore the striped murrel chemokine signaling pathways and their roles in defense system.
authors.affiliation: Division of Fisheries Biotechnology & Molecular Biology, Department of Biotechnology, Faculty of Science and Humanities, SRM University, Kattankulathur, 603 203 Chennai, Tamil Nadu, India.
authors.forename: Prasanth
authors.initials: P
authors.lastname: Bhatt
authors.affiliation: Division of Fisheries Biotechnology & Molecular Biology, Department of Biotechnology, Faculty of Science and Humanities, SRM University, Kattankulathur, 603 203 Chennai, Tamil Nadu, India.
authors.forename: Mukesh Kumar
authors.initials: MK
authors.lastname: Chaurasia
authors.affiliation: Division of Fisheries Biotechnology & Molecular Biology, Department of Biotechnology, Faculty of Science and Humanities, SRM University, Kattankulathur, 603 203 Chennai, Tamil Nadu, India.
authors.forename: Rajesh
authors.initials: R
authors.lastname: Palanisamy
authors.affiliation: Division of Fisheries Biotechnology & Molecular Biology, Department of Biotechnology, Faculty of Science and Humanities, SRM University, Kattankulathur, 603 203 Chennai, Tamil Nadu, India.
authors.forename: Venkatesh
authors.initials: V
authors.lastname: Kumaresan
authors.affiliation: Division of Fisheries Biotechnology & Molecular Biology, Department of Biotechnology, Faculty of Science and Humanities, SRM University, Kattankulathur, 603 203 Chennai, Tamil Nadu, India; Department of Microbiology, SRM Arts & Science College, Kattankulathur, 603 203 Chennai, India.
authors.forename: Abirami
authors.initials: A
authors.lastname: Arasu
authors.affiliation: Division of Fisheries Biotechnology & Molecular Biology, Department of Biotechnology, Faculty of Science and Humanities, SRM University, Kattankulathur, 603 203 Chennai, Tamil Nadu, India; Department of Biotechnology, SRM Arts & Science College, Kattankulathur 603 203 Chennai, India.
authors.forename: Akila
authors.initials: A
authors.lastname: Sathyamoorthi
authors.affiliation: Institute for Cellular and Molecular Biology, The University of Texas at Austin, 1 University Station A4800, Austin, TX 78712, USA.
authors.forename: Annie J
authors.initials: AJ
authors.lastname: Gnanam
authors.affiliation: Department of Biotechnology, Faculty of Applied Sciences, AIMST University, Semeling Bedong, 08100 Bedong, Kedah, Malaysia.
authors.forename: Marimuthu
authors.initials: M
authors.lastname: Kasi
authors.affiliation: Lab PCN 206, Microbiology Division, CSIR - Central Drug Research Institute, B.S. 10/1, Sector 10, Jankipuram Extension, Sitapur Road, Lucknow 226031, Uttar Pradesh, India.
authors.forename: Mukesh
authors.initials: M
authors.lastname: Pasupuleti
authors.affiliation: PG and Research Department of Biotechnology, Bharath College of Science and Management, Thanjavur 613 005, Tamil Nadu, India.
authors.forename: Harikrishnan
authors.initials: H
authors.lastname: Ramaswamy
authors.affiliation: Division of Fisheries Biotechnology & Molecular Biology, Department of Biotechnology, Faculty of Science and Humanities, SRM University, Kattankulathur, 603 203 Chennai, Tamil Nadu, India. Electronic address: jesuaraj@hotmail.com.
authors.forename: Jesu
authors.initials: J
authors.lastname: Arockiaraj
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001419:Bacteria / Q000276:immunology; D001483:Base Sequence; D016000:Cluster Analysis; D017931:DNA Primers / Q000235:genetics; D018076:DNA, Complementary / Q000235:genetics; D020869:Gene Expression Profiling; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010473:Perciformes / Q000235:genetics*; D010802:Phylogeny; D011487:Protein Conformation; D054367:Receptors, CXCR3 / Q000235:genetics / Q000378:metabolism*; D043562:Receptors, G-Protein-Coupled / Q000235:genetics; D017422:Sequence Analysis, DNA; D017385:Sequence Homology; D012977:Sodium Nitrite / Q000633:toxicity*; D013045:Species Specificity
chemical_list: D017931:DNA Primers; D018076:DNA, Complementary; D054367:Receptors, CXCR3; D043562:Receptors, G-Protein-Coupled; D012977:Sodium Nitrite
keywords: Chemokine; Cloning; Gene expression; Murrel; Toxicity