Ubiquitylation of terminal deoxynucleotidyltransferase inhibits its activity

PLoS One. 2012;7(7):e39511. doi: 10.1371/journal.pone.0039511. Epub 2012 Jul 11.

Abstract

Terminal deoxynucleotidyltransferase (TdT), which template-independently synthesizes DNA during V(D)J recombination in lymphoid cells, is ubiquitylated by a BPOZ-2/Cul3 complex, as the ubiquitin ligase, and then degraded by the 26 S proteasome. We show here that TdT is ubiquitylated by the Cul3-based ubiquitylation system in vitro. Because TdT could also be ubiquitylated in the absence of Cul/BPOZ-2, we determined that it could also be directly ubiquitylated by the E2 proteins UbcH5a/b/c and UbcH6, E3-independently. Furthermore, the ubiquitylated TdT inhibited its nucleotidyltransferase activity.

MeSH terms

  • Animals
  • Cattle
  • Cullin Proteins / genetics
  • Cullin Proteins / metabolism
  • DNA Nucleotidylexotransferase / genetics
  • DNA Nucleotidylexotransferase / metabolism*
  • Feedback, Physiological*
  • Gene Expression Regulation*
  • Gene Library
  • HeLa Cells
  • Humans
  • Liver / cytology
  • Liver / metabolism
  • Plasmids
  • Proteasome Endopeptidase Complex / genetics
  • Proteasome Endopeptidase Complex / metabolism
  • Proteolysis
  • Repressor Proteins / genetics
  • Repressor Proteins / metabolism
  • Thymus Gland / cytology
  • Thymus Gland / metabolism
  • Transfection
  • Ubiquitin-Conjugating Enzymes / genetics
  • Ubiquitin-Conjugating Enzymes / metabolism
  • Ubiquitin-Protein Ligases / genetics
  • Ubiquitin-Protein Ligases / metabolism
  • Ubiquitination / genetics*

Substances

  • ABTB1 protein, human
  • CUL3 protein, human
  • Cullin Proteins
  • Repressor Proteins
  • UBE2D1 protein, human
  • UBE2D2 protein, human
  • UBE2D3 protein, human
  • Ubiquitin-Conjugating Enzymes
  • Ubiquitin-Protein Ligases
  • DNA Nucleotidylexotransferase
  • Proteasome Endopeptidase Complex
  • ATP dependent 26S protease