Protein Phosphatase 6, Regulatory Subunit 1 (PPP6R1)

Protein phosphatase regulatory subunits, such as SAPS1, modulate the activity of protein phosphatase catalytic subunits by restricting substrate specificity, recruiting substrates, and determining the intracellular localization of the holoenzyme. SAPS1 is a regulatory subunit for the protein phosphatase-6 catalytic subunit (PPP6C).The deduced 829-amino acid protein has a central alpha-helical SAPS domain of about 400 amino acids. Northern blot analysis detected a 4-kb transcript that was highly expressed in testis and moderately expressed in all other tissues examined. Western blot analysis of fractionated HeLa and HEK293 cells showed PP6R1 in the cytosolic fraction.The transcript contains a repetitive element in its 5-prime end, and the deduced protein contains 754 amino acids.