In h- cells under nutritional starvation, P-factor induces alteration of cell morphology toward mating, arrest of the cell cycle at the G1 phase prior to the initiation of DNA synthesis and indirect transcriptional activation of the sxa2 gene which down-regulates the signaling pathway. The Pro-P-factor precursor carries 4 repetitive units. The second and fourth units generate the major form of the P-factor in the cell. The first and the third units encode slightly different peptides, the fate of which is unclear. Proteolytically cleaved by kpr, probably at the C-terminal side of dibasic Lys-Arg residues. Glycosylated. Most of the precursor molecules are glycosylated on at least one site, but only a small proportion are glycosylated on both sites.