Molecular cloning, characterization and three-dimensional modeling of porcine nectin-2/CD112

Nectin-2, also known as poliovirus receptor-related 2 or CD112, has been identified in many animals and plays a crucial role in cell recognition and adhesion. Here we report the identification of two porcine Nectin-2 (poNectin-2) isoforms. The open reading frame (ORF) of 1440 nucleotides (nt) of poNectin-2alpha encodes 479 amino acids (aa). poNectin-2delta gene consists of 1620nt of ORF with 539aa. The deduced aa sequences of poNectin-2alpha and poNectin-2delta gene exhibit high identity with human (74% and 79%) and mouse (71% and 76%) orthologs, respectively. The ectodomains of deduced poNectin-2 protein share the structural feature of mammalian Nectin-2, including a conserved cysteine skeleton important for the formation of the three-dimensional structure. RT-PCR analysis showed that the mRNA of both poNectin-2 isoforms was broadly expressed in various tissues and cells. poNectin-2 gene was mapped to chromosome 6q21. Information from this study will help to elucidate the Nectin-2 pathway in xenotransplant immunity.