Tyrosine phosphatases in steroidogenic cells: Regulation and function

In adrenocortical and Leydig cells PKA activation by trophic hormones increases the activity of protein tyrosine phosphatases and also induces the expression of MAP kinase phosphatase 1 (MKP-1), a dual activity protein phosphatase (serine/threonine and tyrosine). This work summarizes the knowledge on the regulation and the role played by cAMP-activated tyrosine phosphatases as well as MKP-1 in the hormonal activation of the acute and chronic phases of steroidogenesis.