title: PKCdelta-dependent functional switch of rpS3 between translation and DNA repair.
abstract: Ribosomal protein S3 (rpS3) is critically involved in translation as a component of the 40S ribosomal subunit and participates in the processing of DNA damage, functioning as a damage DNA endonuclease. However, it is not yet known how the function of rpS3 switches between translation and DNA repair. Here we show that PKCdelta phosphorylates rpS3 resulting in its mobilization in the nucleus to repair damaged DNA. Phosphorylated rpS3 was only detected in non-ribosomal rpS3 and the repair endonuclease activity of rpS3 was increased by its phosphorylation. In addition, rpS3 knock-down cells showed more sensitivity to genotoxic stress than control cells, and this sensitivity was corrected by overexpressed wild-type rpS3 but not by phosphorylation defective rpS3. In conclusion, we propose that the destiny of rpS3 molecules between translation and DNA repair is regulated by PKCdelta-dependent phosphorylation.
authors.affiliation: Laboratory of Biochemistry, School of Life Sciences and Biotechnology, and BioInstitute, Korea University, Seoul 136-701, Republic of Korea.
authors.forename: Tae-Sung
authors.initials: TS
authors.lastname: Kim
authors.forename: Hag Dong
authors.initials: HD
authors.lastname: Kim
authors.forename: Joon
authors.initials: J
authors.lastname: Kim
mesh_terms: D002460:Cell Line; D002467:Cell Nucleus / Q000201:enzymology; D002470:Cell Survival; D004260:DNA Repair; D004720:Endonucleases / Q000378:metabolism; D004789:Enzyme Activation; D006801:Humans; D008954:Models, Biological; D010766:Phosphorylation; D019000:Phosphotyrosine / Q000378:metabolism; D011485:Protein Binding; D014176:Protein Biosynthesis; D051745:Protein Kinase C-delta / Q000378:metabolism*; D021381:Protein Transport; D012269:Ribosomal Proteins / Q000378:metabolism*; D012270:Ribosomes / Q000378:metabolism; D019061:src-Family Kinases / Q000378:metabolism
chemical_list: D012269:Ribosomal Proteins; C044152:ribosomal protein S3; D019000:Phosphotyrosine; D019061:src-Family Kinases; D051745:Protein Kinase C-delta; D004720:Endonucleases