Cloning of the cDNA encoding the porcine p55 tumor necrosis factor receptor

We have utilized RT-PCR to clone the porcine p55TNFR cDNA, encoding the 55-kDa tumor necrosis factor receptor (TNFR), encompassing the entire coding region and most of the 3' untranslated region. PCR was performed using total cellular RNA of porcine kidney cell line 15 [PK(15)] and primers for the human p55TNFR. Since the length of the entire fragment was over 2000 bp, we fused two amplified subfragments with the help of a restriction endonuclease. The entire fragment was cloned and its amino acid (aa) sequence was compared to the human, rat and mouse p55TNFR. This comparison revealed identities of 79, 71 and 72%, respectively. The highest identities of 90, 80 and 85% were detected in the so called "death domain" for the human, rat and mouse sequences, respectively. This domain is crucial for the cytotoxic signal transduction of p55TNFR.