Identification of a decay in transcription potential that results in elongation factor dependence of RNA polymerase II.
The rate of RNA elongation by RNA polymerase II (pol II) is affected by DNA sequences called intrinsic arrest sites. Efficient transcription through these sites requires elongation factor SII. In addition to the sequence-specific features of the DNA, we show that the acquisition of SII-dependence is a function of its "dwell-time" at an arrest site. This temperature-dependent decay in elongation potential appears irreversible, implying that factor-dependent and factor-independent elongation complexes are not mutually interconvertible at this position. TFIIF and NH4Cl are known to increase the elongation rate of pol II. Both agents preempt arrest, consistent with the idea that elongation dwell time influences the process. TFIIF and SII act upon different steps in a complementary way to prevent or resolve arrest, respectively. They are probably instrumental in facilitating the efficient transcription of large eukaryotic genes in vivo.
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Graduate Program in Biochemistry & Molecular Biology, Emory University School of Medicine, Atlanta, Georgia 30322, USA.
Reines
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D000643:Ammonium Chloride / Q000494:pharmacology; D000818:Animals; D001483:Base Sequence; D003570:Cytidine Triphosphate / Q000378:metabolism; D004247:DNA / Q000737:chemistry / Q000378:metabolism*; D047908:Intracellular Signaling Peptides and Proteins; D007700:Kinetics; D008099:Liver / Q000378:metabolism; D008969:Molecular Sequence Data; D015514:Oncogene Proteins, Fusion; D011506:Proteins / Q000378:metabolism*; D012319:RNA Polymerase II / Q000378:metabolism*; D051381:Rats; D011994:Recombinant Proteins / Q000378:metabolism; D012265:Ribonucleotides / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism*; D019473:Transcription Factors, TFII; D014158:Transcription, Genetic / Q000187:drug effects
D047908:Intracellular Signaling Peptides and Proteins; D015514:Oncogene Proteins, Fusion; D011506:Proteins; D011994:Recombinant Proteins; D012265:Ribonucleotides; C071236:STIL protein, human; D014157:Transcription Factors; D019473:Transcription Factors, TFII; D000643:Ammonium Chloride; D003570:Cytidine Triphosphate; D004247:DNA; D012319:RNA Polymerase II; C056604:transcription factor TFIIF