Molecular cloning and functional characterization of bottlenose dolphin (Tursiops truncatus) tumor necrosis factor alpha

Bottlenose dolphin tumor necrosis factor alpha (doTNF-α) cDNA was cloned by reverse transcription polymerase chain reaction (RT-PCR) and the nucleic and deduced amino acid sequences were determined. The sequence of the cDNA clones shows that doTNF-α has an open reading frame of 699 bp encoding 233 amino acids. The nucleic acid sequence of doTNF-α indicates 90, 88, 87, and 79% similarity with the cattle, pig, human, and mouse TNF-α gene, respectively. Based on the analysis of human and mouse TNF-α molecules, doTNF-α is processed to a mature protein with 157 amino acids. The 233 amino acids precursor has a hydrophobic region that could serve as a transmembrane domain. The recombinant doTNF-α expressed in Escherichia coli as a glutathione S-transferase fusion protein reacted with anti-human TNF-α antibody and exerted cytotoxity to the TNF-α sensitive murine cell line L929.