title: Identification and in silico analysis of a novel troponin C like gene from Ruditapes philippinarum (Bivalvia: Veneridae) and its transcriptional response for calcium challenge.
abstract: Troponin C (TnC) is one of the subunits composing the troponin complex, which is primarily expressed in muscle tissue and plays a major role in regulating contractility. We have identified a novel TnC-like gene (RpTnC) from the Ruditapes philippinarum Manila clam. Sequence analysis indicated that RpTnC has a 450bp coding sequence, encoding a 150 amino acid protein with a molecular mass of 17.4 kDa. The RpTnC protein consisted of four EF-hand motifs (I-IV), each with a Ca2+-binding site. In silico comparative analysis of protein sequence showed that only site IV, demonstrating a conserved stretch (DxDxSx6E), is functionally active for Ca2+-coordination. Moreover, RpTnC was homologically (61.3% identity) and phylogenetically closest to Japanese flying squid TnC. The mRNA expression analysis using quantitative real-time PCR revealed a differential basal-expression of RpTnC transcripts in six different clam tissues, with higher levels in adductor muscle and mantle. Intramuscular administration of CaCl2 caused a prominent upregulation of RpTnC transcripts in adductor muscle (~5 fold). Collectively, our findings suggest that the TnC homolog of Manila clam identified in this study may be involved in important role(s) in clam physiology, mainly in its muscle tissues, and its transcription could be significantly influenced by increased Ca2+ levels.
authors.affiliation: Department of Marine Life Sciences, School of Marine Biomedical Sciences, Jeju National University, Jeju Special Self-Governing Province 690-756, Republic of Korea.
authors.forename: Navaneethaiyer
authors.initials: N
authors.lastname: Umasuthan
authors.forename: Don Anushka Sandaruwan
authors.initials: DA
authors.lastname: Elvitigala
authors.forename: Kasthuri
authors.initials: K
authors.lastname: Saranya Revathy
authors.forename: Youngdeuk
authors.initials: Y
authors.lastname: Lee
authors.forename: Ilson
authors.initials: I
authors.lastname: Whang
authors.forename: Myoung-Ae
authors.initials: MA
authors.lastname: Park
authors.forename: Jehee
authors.initials: J
authors.lastname: Lee
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D049872:Bivalvia / Q000235:genetics*; D002118:Calcium / Q000378:metabolism*; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D008969:Molecular Sequence Data; D010802:Phylogeny; D011487:Protein Conformation; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D014158:Transcription, Genetic; D019209:Troponin C / Q000235:genetics* / Q000378:metabolism
chemical_list: D018076:DNA, Complementary; D012333:RNA, Messenger; D019209:Troponin C; D002118:Calcium