title: Ribosomal protein S3 is stabilized by sumoylation.
abstract: Human ribosomal protein S3 (rpS3) acts as a DNA repair endonuclease. The multiple functions of this protein are regulated by post-translational modifications including phosphorylation and methylation. Using a yeast-two hybrid screen, we identified small ubiquitin-related modifier-1 (SUMO-1) as a new interacting partner of rpS3. rpS3 interacted with SUMO-1 via the N- and C-terminal regions. We also observed sumoylation of rpS3 in Escherichia coli and mammalian cell systems. Furthermore, we discovered that one of three lysine residues, Lys18, Lys214, or Lys230, was sumoylated in rpS3. Interestingly, sumoylated rpS3 was resistant to proteolytic activity, indicating that SUMO-1 increased the stability of the rpS3 protein. We concluded that rpS3 is covalently modified by SUMO-1 and this post-translational modification regulates rpS3 function by increasing rpS3 protein stability.
authors.affiliation: Laboratory of Biochemistry, School of Life Sciences and Biotechnology, and BioInstitute, Korea University, Seoul 136-701, Republic of Korea.
authors.forename: Chang-Young
authors.initials: CY
authors.lastname: Jang
authors.forename: Hyun-Seock
authors.initials: HS
authors.lastname: Shin
authors.forename: Hag Dong
authors.initials: HD
authors.lastname: Kim
authors.forename: Jung Woo
authors.initials: JW
authors.lastname: Kim
authors.forename: Soo-Young
authors.initials: SY
authors.lastname: Choi
authors.forename: Joon
authors.initials: J
authors.lastname: Kim
mesh_terms: D004926:Escherichia coli / Q000378:metabolism; D057809:HEK293 Cells; D006801:Humans; D047468:Immunoprecipitation; D055550:Protein Stability; D012269:Ribosomal Proteins / Q000235:genetics / Q000378:metabolism*; D025842:SUMO-1 Protein / Q000235:genetics / Q000378:metabolism*; D058207:Sumoylation; D020798:Two-Hybrid System Techniques
chemical_list: D012269:Ribosomal Proteins; D025842:SUMO-1 Protein; C044152:ribosomal protein S3