Nuclear inhibitor of protein phosphatase 1 is an enzyme that in humans is encoded by the PPP1R8 gene.[5][6][7]
This gene, through alternative splicing, encodes three different isoforms. Two of the protein isoforms encoded by this gene are specific inhibitors of type 1 serine/threonine protein phosphatases and can bind but not cleave RNA. The third protein isoform lacks the phosphatase inhibitory function but is a single-strand endoribonuclease comparable to RNase E of E. coli. This isoform requires magnesium for its function and cleaves specific sites in A+U-rich regions of RNA.[7]
PPP1R8 has been shown to interact with PPP1CA,[8][9] Histone deacetylase 2,[8] SF3B1[10] EED[8] and the EZH2 domain of PRC2.[11]