Molecular cloning of a porcine (Sus scrofa) apoptosis inhibitory ligand, Netrin-1, and its receptor, p53RDL1

The apoptosis inhibitory ligand (Netrin-1) and its receptor (p53-regulated receptor for death and life: p53RDL1) play an important role in the regulation of selective apoptosis. When Netrin-1 binds to p53RDL1, p53-dependent apoptosis is inhibited. We identified porcine (Sits scrofa) cDNAs encoding Netrin-1 [pNetrin-1; 1,803 base pairs (bp) and 600 amino acids (aa)] and p53RDL1 (pp53RDL1; 2,838 bp and 945 aa). Porcine p53RDL1 (pp53RDL1) contains a death domain (DD), a tandem specific amino acid region, in its C-terminal, suggesting that it mediates death signaling by binding with other pro-apoptotic factors via the DD. Porcine Netrin-1 (pNetrin-1), pp53RDL1 and the DD in pp53RDL1 showed high levels of identity in aa sequence with human and murine Netrin-1 (98 and 97%, respectively), p53RDL1 (94 and 91%, respectively) and the DD in p53RDL1 (96 and 95%, respectively). Reverse transcription-polymerase chain reaction (RT-PCR) revealed that the levels of pNetrin-1 and pp53RDL1 mRNAs were moderate in granulosa cells compared with their expression in other tissues and that their levels during follicular atresia were stable. The Netrin-1 and p53RDL1 system may regulate the induction of apoptosis in porcine granulosa cells.