Phosphorylation status of nuclear ribosomal protein S3 is reciprocally regulated by protein kinase Cδ and protein phosphatase 2A

Tae Sung Kim, Hag Dong Kim, Hyun Seock Shin, Joon Kim

Research output: Contribution to journalArticle

19 Citations (Scopus)

Abstract

It has been shown previously that ribosomal protein S3 (rpS3) has an endonuclease activity, which is increased by protein kinase Cδ (PKCδ)-dependent phosphorylation. However, the reciprocal mechanism for rpS3 dephosphorylation is not known. In this study, we examined phosphatases involved in rpS3 dephosphorylation, and we determined that rpS3 is specifically dephosphorylated by protein phosphatase 2A (PP2A). By immunoprecipitation assay, rpS3 only interacted with PP2Ac but not with protein phosphatase 1. The interaction between rpS3 and PP2Ac occurred only in the nuclear fraction. Moreover, the PP2Ac association with rpS3 was identified in cells transfected with wild-type rpS3 but not with mutant rpS3 lacking PKCδ phosphorylation sites. PP2A inhibition using okadaic acid induced rpS3 phosphorylation. The level of phosphorylated rpS3 in cells was decreased by the overexpression of PP2Ac and was increased by the down-regulation of PP2Ac. Taken together, these results suggest that oxidative stress regulates the phosphorylation status of nonribosomal rpS3 by both activating PKCδ and blocking the PP2A interaction with rpS3.

Original languageEnglish
Pages (from-to)21201-21208
Number of pages8
JournalJournal of Biological Chemistry
Volume284
Issue number32
DOIs
Publication statusPublished - 2009 Aug 7

ASJC Scopus subject areas

  • Biochemistry
  • Cell Biology
  • Molecular Biology

Fingerprint Dive into the research topics of 'Phosphorylation status of nuclear ribosomal protein S3 is reciprocally regulated by protein kinase Cδ and protein phosphatase 2A'. Together they form a unique fingerprint.

  • Cite this