Scientists at National Institute on Alcohol Abuse and Alcoholism describe research in life sciences
2007 MAY 1 -- Research findings, "Transcriptional bypass of bulky DNA lesions causes new mutant RNA transcripts in human cells," are discussed in a new report. "Here, we characterize the mutant transcripts resulting from bypass of an 8,5'-cyclo-2'-deoxyadenosine (cyclo-dA) or cyclobutane pyrimidine dimer (CPD) by human RNA polymerase II (Pol II) in vivo. With the cyclo-dA lesion, we observed two new types of mutant transcripts," scientists in the United States report. "In the first type, the polymerase inserted uridine opposite the lesion and then misincorporated adenosine opposite the template deoxyadenosine downstream (5') of the lesion. The second type contained deletions of 7, 13 or 21 nucleotides (nt) after uridine incorporation opposite the lesion. The frequency of the different types of transcript from the cyclo-dA lesion in mutant human cell lines suggests that the Cockayne syndrome B protein affects the probability of deletion transcript formation. With the CPD-containing construct, we also detected rare transcripts containing 12 nt deletions," wrote C. Marietta and colleagues, National Institute on Alcohol Abuse and Alcoholism. The researchers concluded: "These results indicate that RNA pol II in living human cells can bypass helix-distorting DNA lesions that are substrates for nucleotide excision repair, resulting in transcriptional mutagenesis." Marietta and colleagues published their study in Embo Reports (Transcriptional bypass of bulky DNA lesions causes new mutant RNA transcripts in human cells. Embo Reports, 2007;8(4):388-93). For additional information, contact C. Marietta, National Institute on Alcohol Abuse and Alcoholism, Section on Molecular Neurobiology, Laboratory of Neurogenetics, 5625 Fishers Lane, Room 3S-32, MSC 9412, Bethesda, Maryland 20892 USA. The publisher's contact information for the journal Embo Reports is: Nature Publishing Group, Macmillan Building, 4 Crinan St., London N1 9XW, England. Keywords: United States, Bethesda, Life Sciences. This article was prepared by Science Letter editors from staff and other reports. Copyright 2007, Science Letter via NewsRx.com.
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