Protein phosphatase which positively regulates biosynthesis of the ubiquinone, coenzyme Q (PubMed:30267671). Dephosphorylates the ubiquinone biosynthesis protein COQ7 which is likely to lead to its activation (PubMed:30267671). H2O + O-phospho-L-seryl-[protein] = L-seryl-[protein] + phosphate H2O + O-phospho-L-threonyl-[protein] = L-threonyl-[protein] + phosphate Binds 2 magnesium or manganese ions per subunit. Inhibited by sodium orthovanadate. Expressed in keratinocytes (at protein level). By hydrogen peroxide and nutrional stress (such as low glucose) (PubMed:30267671). Up-regulated during lymphocyte activation (PubMed:15177553). Belongs to the PP2C family.