The poly(A) polymerase Star-PAP is regulated by stably associated phosphoinositide messengers.

ABSTRACT: Star-PAP is a noncanonical poly(A) polymerase that controls gene expression. Star-PAP was previously reported to bind PIPKI⍺ and its product PI(4,5)P₂, which regulate Star-PAP activity and expression of specific genes. Recent studies have revealed a nuclear p53-phosphoinositide signaling pathway in which the phosphatidylinositol transfer proteins (PITPs) and phosphoinositide kinases/phosphatases bind p53 to sequentially modify p53-linked phosphoinositides and regulate p53 function. Here, we demonstrate that multiple phosphoinositides are also coupled to Star-PAP in response to stress. This pathway is initiated by PITP⍺/β binding to Star-PAP, and the Star-PAP-phosphoinositide complexes are sequentially modified by PI4KII⍺, PIPKI⍺, IPMK, and PTEN. The formation of Star-PAP-phospho

SUBMITTER: Wen T 

PROVIDER: S-EPMC12284501 | biostudies-literature | 2025 Aug

REPOSITORIES: biostudies-literature