Protein phosphatase 2Cα expression in normal human tissues: an immunohistochemical study

. Protein phosphatase (PP2Cα) is a member of the mammalian serine threonine-specific protein phosphatases family. We produced monoclonal antibodies against the recombinant PP2Cα and evaluated the immunoreactivity of normal human tissues. The reactivity was strong in normal skin, the digestive tract, lung, kidney, breast, prostate, endocrine glands, and brain, while it was moderate in the ovary, testis, and liver. Epithelial cells revealed high levels of PP2Cα expression, but stromal cells, including fibroblasts and endothelial cells, showed no or little PP2Cα expression. Given the broad reactivity in endocrine and secreting epithelial cells, we propose that PP2Cα expression might contribute to secretory cell function.