کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1980897 | 1061887 | 2008 | 8 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
hRev7, putative subunit of hPolζ, plays a critical role in survival, induction of mutations, and progression through S-phase, of UV(254 nm)-irradiated human fibroblasts
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کلمات کلیدی
موضوعات مرتبط
علوم زیستی و بیوفناوری
بیوشیمی، ژنتیک و زیست شناسی مولکولی
زیست شیمی
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چکیده انگلیسی
Translesion synthesis (TLS) refers to mechanisms by which specialized DNA polymerases incorporate nucleotides opposite fork-blocking lesions and extend replication until standard replicative polymerases take over. The first eukaryotic TLS polymerase discovered, S. cerevisiae Polζ, consists of catalytic subunit Rev3 and non-catalytic subunit Rev7. Human homologs of these two proteins have been identified. Studies by Lawrence, Maher, and colleagues comparing UV(254 nm)-irradiated human fibroblast cell strains expressing high levels of hRev3 antisense to their normal parental strains demonstrated that there was no difference in cell survival, but that the frequency of UV-induced mutations in the derivative strains was 10-fold lower than that of the parental strains, indicating that hRev3 plays a critical role in such mutagenesis. To examine the role of hRev7 in TLS, we generated human fibroblasts expressing hRev7 siRNA, identified two derivative cell strains with significantly reduced levels of hRev7, and compared them to their parental strain and a vector control for cell survival, induction of mutations, and ability to traverse the cell cycle following exposure to UV radiation. Cells with reduced hRev7 were â¼2-times more sensitive to UV-induced cytotoxicity than the controls, indicating that unlike hRev3, hRev7 plays a protective role for cells exposed to UV radiation. When these cell strains were assayed for the frequency of mutations induced by UV in their HPRT gene, cell stains with reduced hRev7 were 5-times less sensitive to UV-induced mutagenesis than control strains. In addition, when these four strains were synchronized at the G1/S border, released from the block, UV-irradiated, and allowed to traverse the cell cycle, the rate of progression through S-phase of the cell strains with reduced hRev7 was significantly slower than that of the control strains. These data strongly support the hypothesis that hRev7 is required for TLS past UV-photoproducts, and together with hRev3, comprise hPolζ.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: DNA Repair - Volume 7, Issue 4, 2 April 2008, Pages 597-604
Journal: DNA Repair - Volume 7, Issue 4, 2 April 2008, Pages 597-604
نویسندگان
Kristin McNally, Jessica A. Neal, Terrence P. McManus, J. Justin McCormick, Veronica M. Maher,