The four isoforms of the serine/threonine phosphoprotein phosphatase 1 (PP1), derived from three genes, are among the most conserved proteins known. The Ppp1cc gene encodes two alternatively spliced variants, PPP1CC1 and PPP1CC2. Global... more
The four isoforms of the serine/threonine phosphoprotein phosphatase 1 (PP1), derived from three genes, are among the most conserved proteins known. The Ppp1cc gene encodes two alternatively spliced variants, PPP1CC1 and PPP1CC2. Global deletion of Ppp1cc gene, that causes loss of both isoforms, results in infertility due to impaired spermatogenesis. This phenotype was assumed to be due to the loss of PPP1CC2, which is abundant in testis. While PPP1CC2 is predominant, other PP1 isoforms are also expressed in testis. Given the significant homology between the four PP1 isoforms, the lack of compensation by the other PP1 isoforms for loss of one, only in testis, is surprising. Here we document, for the first time, expression patterns of the PP1 isoforms in post-natal developing and adult mouse testis. The timing and sites of testis expression of PPP1CC1 and PPP1CC2 in testis are non-overlapping. PPP1CC2 is the only one of the four PP1 isoforms not detected in sertoli cells and spermato...
