کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
10823586 | 1061910 | 2005 | 13 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Comparative TFIIS-mediated transcript cleavage by mammalian RNA polymerase II arrested at a lesion in different transcription systems
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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
Upon prolonged arrest at a cyclobutane pyrimidine dimer (CPD), RNAPII can reverse-translocate, misaligning the 3â²-end of the RNA from its active site. Transcription factor SII (TFIIS) is required for cleavage of the disengaged 3â²-end and restoration of its correct positioning. We have previously shown in vitro that when RNAPII is arrested at a CPD, TFIIS-induced cleavage results in shortened transcripts. Here, we hypothesized that the pattern of transcript cleavage does not depend solely upon TFIIS itself, but also on some other general transcription factors (GTFs) and/or their effects on RNAPII. To test this hypothesis we compared three in vitro transcription systems which differ with respect to the mode of initiation and the requirement for GTFs. The first consisted of RNAPII and GTFs from rat liver, and required a eukaryotic promoter for initiation. The other two supported transcription in the absence of any GTFs or promoter sequences. In each case, a CPD on the transcribed strand was a complete block for RNAPII translocation. However, the effect of TFIIS on transcript cleavage varied. In the promoter-initiated system, distinct transcripts up to about 20 nucleotides shorter than the uncleaved original one were produced. In the other two systems, the transcripts were degraded nearly completely. Introduction of GTFs partially interfered with cleavage, but failed to reproduce the pattern of transcript lengths observed with the promoter-initiated system. Our results suggest that the extent of TFIIS-mediated transcript cleavage is a well-orchestrated process, depending upon other factors (or their effects on RNAPII), in addition to TFIIS itself.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: DNA Repair - Volume 4, Issue 10, 28 September 2005, Pages 1075-1087
Journal: DNA Repair - Volume 4, Issue 10, 28 September 2005, Pages 1075-1087
نویسندگان
Virginia S. Kalogeraki, Silvia Tornaletti, Priscilla K. Cooper, Philip C. Hanawalt,