Active transcriptomic and proteomic reprogramming in the C. elegans nucleotide excision repair mutant xpa-1

Nucleic Acids Res. 2013 May 1;41(10):5368-81. doi: 10.1093/nar/gkt225. Epub 2013 Apr 10.

Abstract

Transcription-blocking oxidative DNA damage is believed to contribute to aging and to underlie activation of oxidative stress responses and down-regulation of insulin-like signaling (ILS) in Nucleotide Excision Repair (NER) deficient mice. Here, we present the first quantitative proteomic description of the Caenorhabditis elegans NER-defective xpa-1 mutant and compare the proteome and transcriptome signatures. Both methods indicated activation of oxidative stress responses, which was substantiated biochemically by a bioenergetic shift involving increased steady-state reactive oxygen species (ROS) and Adenosine triphosphate (ATP) levels. We identify the lesion-detection enzymes of Base Excision Repair (NTH-1) and global genome NER (XPC-1 and DDB-1) as upstream requirements for transcriptomic reprogramming as RNA-interference mediated depletion of these enzymes prevented up-regulation of genes over-expressed in the xpa-1 mutant. The transcription factors SKN-1 and SLR-2, but not DAF-16, were identified as effectors of reprogramming. As shown in human XPA cells, the levels of transcription-blocking 8,5'-cyclo-2'-deoxyadenosine lesions were reduced in the xpa-1 mutant compared to the wild type. Hence, accumulation of cyclopurines is unlikely to be sufficient for reprogramming. Instead, our data support a model where the lesion-detection enzymes NTH-1, XPC-1 and DDB-1 play active roles to generate a genomic stress signal sufficiently strong to result in transcriptomic reprogramming in the xpa-1 mutant.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antioxidants / metabolism
  • Caenorhabditis elegans / genetics
  • Caenorhabditis elegans / growth & development
  • Caenorhabditis elegans / metabolism
  • Caenorhabditis elegans Proteins / genetics*
  • DNA Glycosylases / genetics
  • DNA Repair*
  • Endonucleases / genetics
  • Mutation
  • Proteome*
  • Purines / metabolism
  • Transcriptome*
  • Ubiquitinated Proteins / metabolism
  • Xeroderma Pigmentosum Group A Protein / genetics*

Substances

  • Antioxidants
  • Caenorhabditis elegans Proteins
  • Proteome
  • Purines
  • Ubiquitinated Proteins
  • XPA-1 protein, C elegans
  • Xeroderma Pigmentosum Group A Protein
  • Endonucleases
  • DNA Glycosylases
  • NTH-1 protein, C elegans