These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Repair of damaged DNA by extracts from a xeroderma pigmentosum complementation group A revertant and expression of a protein absent in its parental cell line.
    Author: Jones CJ, Cleaver JE, Wood RD.
    Journal: Nucleic Acids Res; 1992 Mar 11; 20(5):991-5. PubMed ID: 1549511.
    Abstract:
    Cells derived from individuals with mutations in the xeroderma pigmentosum complementation group A gene (XP-A gene) are hypersensitive to UV light and have a severe defect in nucleotide excision repair of damaged DNA. UV-resistant revertant cell lines can arise from XP-A cells in culture. Cells of one such revertant, XP129, were previously shown to remove (6-4) photoproducts from irradiated DNA, but to have poor repair of cyclobutane pyrimidine dimers. To analyze the biochemical nature of the reversion, whole cell extracts were prepared from the SV40-immortalized fibroblast cell lines XP12RO (an XP-A cell line), the revertant XP129 (derived from XP12RO), and 1BR.3N (from a normal individual). The ability of extracts to carry out repair synthesis in UV-irradiated DNA was examined, and immunoblots were performed using antiserum that recognizes XP-A protein. XP12RO extracts exhibited a very low level of repair and no detectable XP-A protein, but repair activity could be conferred by adding purified XP-A protein to the reaction mixture. XP129 extracts have essentially normal repair synthesis consistent with the observation that most repair of UV-irradiated DNA by extracts appears to occur at (6-4) photoproducts. An XP-A polypeptide of normal size was present in XP129, but in reduced amounts. The results indicate that in XP129 a mutational event has converted the inactive XP12RO XP-A gene into a form which expresses an active XP-A protein.
    [Abstract] [Full Text] [Related] [New Search]