Protein phosphatase 1 regulatory subunit 8 (PPP1R8)

Protein phosphatase 1 regulatory subunit 8 (PPP1R8) is a nuclear protein that acts primarily as a regulatory subunit and inhibitor of serine/threonine-protein phosphatase 1 (PP1), controlling its activity in the nucleus[1][2][7]. PPP1R8 has multiple isoforms generated by alternative splicing. Two isoforms serve as specific inhibitors of type 1 serine/threonine protein phosphatases and bind (but do not cleave) RNA, possibly targeting PP1 to RNA-associated substrates; these are also implicated in pre-mRNA splicing, DNA binding, and may act as transcriptional repressors[1][2][3][7]. A third isoform (gamma) lacks the phosphatase inhibitory function but functions as a site-specific endoribonuclease (comparable to bacterial RNase E), cleaving single-stranded RNA at specific A+U-rich regions in a magnesium-dependent manner[1][2][3]. PPP1R8 is essential for cell proliferation and is involved in cell signaling pathways such as β-adrenergic signaling and cAMP-dependent PKA activation[1]. Associated diseases include Xia-Gibbs syndrome and arthrogryposis, distal, type 1A. There are no current drugs directly targeting PPP1R8 in clinical use, and the protein is not considered a routine clinical biomarker[1][2][3][5][7].

Other names

Nuclear inhibitor of protein phosphatase 1NIPP1Nuclear subunit of PP-1Activator of RNA decayARD-1NIPP-1Protein phosphatase 1 regulatory inhibitor subunit 8Nuclear inhibitor of protein phosphatase-1 alphaNuclear inhibitor of protein phosphatase-1 betaRNase EPRO2047