Cloning, structural analysis and expression of cardiac troponin C (TNNC1) gene in goat

Abstract

Cardiac troponin (TNNC1) is the calcium-binding subunit of the myofibril thin filament that regulates excitation-contraction coupling in cardiac muscle. In the study, we cloned TNNC1 gene of goat for the first time (GenBank accession number: HQ640744) and analyzed its tissue expression. Results indicate that TNNC1 was a 161-amino acid polypeptide that had been highly conserved during evolution. Its nucleotide sequence was high and was similar in various animals ranging from 97.94 (cow) to 83.33% (African clawed frog), and the identity of the encoded amino acids varied from 100 (cow) to 92.55% (smelt). Fluorescence quantitative PCR analyses revealed that the TNNC1 gene was selectively expressed in the muscular tissues of goat, was expressed in cardiac tissue and slow skeletal muscle (soleus), but was not expressed in fast skeletal muscle (longissimus muscle, gluteus maximus) and brain, kidney, lung or liver of goat. The amino acid residue of Ca²⁺ binding site II is identical in mammals, aves and fish. This study may provide more insight into the molecular structure, expression patterns and evolution of TNNC1 gene in animal.

Key words: TroponinC1 gene, molecular cloning, structural analysis, expression, goat.