Protein phosphatase 4 core regulatory subunit R2 (PPP4R2), also known as Psy4 in budding yeast, is the regulatory subunit of the histone H2A phosphatase complex. The histone H2A phosphatase complex dephosphorylates H2AS128ph (gamma-H2A) that has been displaced from sites of DNA lesions in the double-stranded DNA break repair process. Dephosphorylation of Psy4 is necessary for efficient recovery from the DNA damage checkpoint [].
