Ubiquitylation-independent degradation of Xeroderma pigmentosum group C protein is required for efficient nucleotide excision repair

Nucleic Acids Res. 2007;35(16):5338-50. doi: 10.1093/nar/gkm550. Epub 2007 Aug 9.

Abstract

The Xeroderma Pigmentosum group C (XPC) protein is indispensable to global genomic repair (GGR), a subpathway of nucleotide excision repair (NER), and plays an important role in the initial damage recognition. XPC can be modified by both ubiquitin and SUMO in response to UV irradiation of cells. Here, we show that XPC undergoes degradation upon UV irradiation, and this is independent of protein ubiquitylation. The subunits of DDB-Cul4A E3 ligase differentially regulate UV-induced XPC degradation, e.g DDB2 is required and promotes, whereas DDB1 and Cul4A protect the protein degradation. Mutation of XPC K655 to alanine abolishes both UV-induced XPC modification and degradation. XPC degradation is necessary for recruiting XPG and efficient NER. The overall results provide crucial insights regarding the fate and role of XPC protein in the initiation of excision repair.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Cell Line
  • Cricetinae
  • Cullin Proteins / physiology
  • DNA Damage
  • DNA Repair*
  • DNA-Binding Proteins / chemistry
  • DNA-Binding Proteins / metabolism*
  • DNA-Binding Proteins / physiology
  • Endonucleases / metabolism
  • Humans
  • Mice
  • Nuclear Proteins / metabolism
  • Small Ubiquitin-Related Modifier Proteins / metabolism
  • Transcription Factors / metabolism
  • Ubiquitin / metabolism
  • Ultraviolet Rays

Substances

  • CUL4A protein, human
  • Cullin Proteins
  • DDB1 protein, human
  • DDB2 protein, human
  • DNA excision repair protein ERCC-5
  • DNA-Binding Proteins
  • Nuclear Proteins
  • Small Ubiquitin-Related Modifier Proteins
  • Transcription Factors
  • Ubiquitin
  • XPC protein, human
  • Endonucleases