Differentiation-dependent enhanced expression of protein phosphatase 2C beta in germ cells of mouse seminiferous tubules

The presence of five distinct isoforms of protein phosphatase 2C beta (PP2C beta-1 similar to-5) is known, In this study, me demonstrate that the mRNA levels of PP2C beta-3, -4 and -5 and PP2C beta protein level increased during the course of the first wave of spermatogenesis in neonatal mouse testis, Northern blot and in situ hybridization analyses revealed that PP2C beta-3, -4 and -5 were expressed predominantly in pachytene spermatocytes and in more highly differentiated germ cells, The substrate specificity of PP2C beta-4 determined with artificial substrates differed from those of PP2C beta-3 and -5, suggesting that the difference in the structure of PP2C beta-3, -4 and -5 reflect their unique physiological functions in testicular germ cells.