A ubiquitin-binding domain in Cockayne syndrome B required for transcription-coupled nucleotide excision repair

Mol Cell. 2010 Jun 11;38(5):637-48. doi: 10.1016/j.molcel.2010.04.017.

Abstract

Transcription-coupled nucleotide excision repair (TC-NER) allows RNA polymerase II (RNAPII)-blocking lesions to be rapidly removed from the transcribed strand of active genes. Defective TCR in humans is associated with Cockayne syndrome (CS), typically caused by defects in either CSA or CSB. Here, we show that CSB contains a ubiquitin-binding domain (UBD). Cells expressing UBD-less CSB (CSB(del)) have phenotypes similar to those of cells lacking CSB, but these can be suppressed by appending a heterologous UBD, so ubiquitin binding is essential for CSB function. Surprisingly, CSB(del) remains capable of assembling nucleotide excision repair factors and repair synthesis proteins around damage-stalled RNAPII, but such repair complexes fail to excise the lesion. Together, our results indicate an essential role for protein ubiquitylation and CSB's UBD in triggering damage incision during TC-NER and allow us to integrate the function of CSA and CSB in a model for the process.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Cell Line / radiation effects
  • Cell Nucleus / metabolism
  • Cockayne Syndrome / genetics
  • Cockayne Syndrome / metabolism
  • DNA Damage
  • DNA Helicases* / genetics
  • DNA Helicases* / metabolism
  • DNA Repair Enzymes* / genetics
  • DNA Repair Enzymes* / metabolism
  • DNA Repair*
  • Humans
  • Molecular Sequence Data
  • Mutation
  • Poly-ADP-Ribose Binding Proteins
  • Promoter Regions, Genetic
  • Protein Structure, Tertiary
  • RNA Polymerase II / genetics
  • RNA Polymerase II / metabolism
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / metabolism
  • Sequence Alignment
  • Tetrahydrofolate Dehydrogenase / genetics
  • Ubiquitin / genetics
  • Ubiquitin / metabolism*
  • Ultraviolet Rays

Substances

  • Poly-ADP-Ribose Binding Proteins
  • Recombinant Fusion Proteins
  • Ubiquitin
  • Tetrahydrofolate Dehydrogenase
  • RNA Polymerase II
  • DNA Helicases
  • ERCC6 protein, human
  • DNA Repair Enzymes