Alterations in expression and structure of the DNA repair gene XRCC1.
The repair-associated gene XRCC1 was previously cloned by complementing the hamster mutant EM9, which has a high rate of spontaneous SCE and hypersensitivity to DNA damaging agents. In analyzing XRCC1 gene expression, similar levels of steady-state mRNA were found in normal cells, Bloom's syndrome cells with altered SCE, and in squamous carcinoma cells with differential X-ray sensitivity. An EcoRI restriction fragment-length polymorphism previously identified in XRCC1 did not correlate with the repair phenotypes of these cells. The mRNA of XRCC1 decreased to 20-40% after treatment of cells with a DNA damaging agent. XRCC1 also showed tissue specific expression in rats. The mRNA levels were high in testis (7-8 fold), ovary (3-4 fold) and brain (4-5 fold), when compared with those in intestine, liver and spleen (1-2 fold). These data and the high levels of XRCC1 protein detected in testis indicate that XRCC1 may play an important role in DNA processing during meiogenesis and recombination in germ cells.
Department of Molecular Pathology, University of Texas M. D. Anderson Cancer Center, Houston 77030.
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Yoo
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Li
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Sacks
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Thompson
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Becker
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Chan
D000595:Amino Acid Sequence; D000818:Animals; D000906:Antibodies; D001816:Bloom Syndrome / Q000235:genetics*; D001921:Brain / Q000502:physiology; D016466:CHO Cells; D002294:Carcinoma, Squamous Cell / Q000235:genetics*; D002460:Cell Line; D006224:Cricetinae; D004260:DNA Repair / Q000235:genetics*; D005260:Female; D015870:Gene Expression; D006801:Humans; D015151:Immunoblotting; D008297:Male; D008969:Molecular Sequence Data; D009928:Organ Specificity; D010053:Ovary / Q000502:physiology; D010455:Peptides / Q000138:chemical synthesis / Q000276:immunology; D012150:Polymorphism, Restriction Fragment Length; D012333:RNA, Messenger / Q000032:analysis / Q000235:genetics / Q000378:metabolism; D051381:Rats; D012854:Sister Chromatid Exchange; D013737:Testis / Q000502:physiology; D014965:X-Rays
D000906:Antibodies; D010455:Peptides; D012333:RNA, Messenger