Protein Phosphatase 1, Regulatory Subunit 8 (PPP1R8)

Nuclear inhibitor of protein phosphatase 1, 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.The 351-amino acid NIPP1 protein is a specific inhibitor of type 1 serine/threonine protein phosphatases. The human ARD1 amino acid sequence is virtually identical to the carboxy terminus of the bovine NIPP1 amino acid sequence.