Proline Rich Nuclear Receptor Coactivator 2 (PNRC2)

Coimmunopurification analysis and protein pull-down assays confirmed the interaction. PNRC2 preferentially interacted with hyperphosphorylated UPF1 and triggered movement of UPF1 into P bodies. Downregulation of PNRC2 impaired the localization of hyperphosphorylated UPF1 to P bodies. PNRC2 also interacted with DCP1A, a component of the decapping complex.

Downregulation of endogenous PNRC2 or UPF1 in HeLa cells via small interfering RNA abrogated NMD and increased the levels of COMMD7 and IARS mRNA, suggesting that these are natural NMD substrates. Furthermore, PNRC2 elicited mRNA degradation when tethered to RNA downstream of the normal termination codon.