Channel catfish (Ictalurus punctatus Rafinesque, 1818) tetraspanin membrane protein family: Identification, characterization and phylogenetic analysis of tetraspanin 3 and tetraspanin 7 (CD231) transcripts

Authors: Yeh, Hung-Yueh; Klesius, Phillip

Submitted to: Fish Physiology and Biochemistry Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/12/2012
Publication Date: 12/1/2012
Citation: Yeh, H., Klesius, P.H. 2012. Channel catfish (Ictalurus punctatus Rafinesque, 1818) tetraspanin membrane protein family: Identification, characterization and phylogenetic analysis of tetraspanin 3 and tetraspanin 7 (CD231) transcripts. Fish Physiology and Biochemistry Journal. 38:1553-1563.

Interpretive Summary: Tetraspanin 3 and tetraspanin 7 proteins are members of the tetraspanin integral membrane protein family. These proteins play many roles in normal functions. In this communication, we sequenced and characterized the channel catfish tetraspanin 3 and tetraspanin 7 complementary deoxyribonucleic acids (cDNA). The full-length nucleotide sequences of channel catfish tetraspanin 3 and tetraspanin 7 cDNA consisted of 1,474 and 1,863 nucleotides, respectively. Each had an open reading frame, which appears to encode a putative peptide of 241 and 251 amino acid residues for tetraspanin 3 and tetraspanin 7, respectively. By comparison with human orthologs, the channel catfish tetraspanin 3 and tetraspanin 7 peptides can be divided into domains, including four transmembrane domains, three intracellular domains, and one of each small and large extracellular loops. The cDNA were detected by reverse transcriptase-polymerase chain reaction in various channel catfish tissues. This result provides important information for further elucidating these tetraspanin proteins in channel catfish infection with microorganisms.

Technical Abstract: Abstract Tetraspanins, a large cell surface protein superfamily characterized by having four transmembrane domains, play many critical roles in physiological and pathological processes. In this study, we report the identification, characterization and phylogenetic analysis of the channel catfish tetraspanin 3 and tetraspanin 7 (CD231) transcripts. The full-length nucleotide sequences of tetraspanin 3 and tetraspanin 7 cDNA have 1453 and 1842 base pairs, respectively. Analysis of the nucleotide sequences reveals that each has one open reading frame, which appears to encode 241 amino acids with calculated molecular mass of 26.8 kDa and 251 amino acids with calculated molecular mass of 27.9 kDa for tetraspanin 3 and tetraspanin 7, respectively. By comparison with the human counterparts, the channel catfish tetraspanin 3 and tetraspanin 7 peptides have four transmembrane domains, three intracellular domains and two (small and large) extracellular domains. In addition, several characteristic features critical for structure and functions in mammalian tetraspanins are also conserved in channel catfish tetraspanin 3 and tetraspanin 7. These results with our previous studies on other channel catfish tetraspanins provide important information for further investigating the roles of various tetraspanins in channel catfish infection with microorganisms.