Differentiation‐dependent enhanced expression of protein phosphatase 2Cβ in germ cells of mouse seminiferous tubules

Abstract

The presence of five distinct isoforms of protein phosphatase 2Cβ (PP2Cβ1∼‐5) is known. In this study, we demonstrate that the mRNA levels of PP2Cβ‐3, ‐4 and ‐5 and PP2Cβ 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 PP2Cβ‐3, ‐4 and ‐5 were expressed predominantly in pachytene spermatocytes and in more highly differentiated germ cells. The substrate specificity of PP2Cβ‐4 determined with artificial substrates differed from those of PP2Cβ‐3 and ‐5, suggesting that the difference in the structure of PP2Cβ‐3, ‐4 and ‐5 reflect their unique physiological functions in testicular germ cells.