Genomic binding profiles of functionally distinct RNA polymerase III transcription complexes in human cells.
Genome-wide occupancy profiles of five components of the RNA polymerase III (Pol III) machinery in human cells identified the expected tRNA and noncoding RNA targets and revealed many additional Pol III-associated loci, mostly near short interspersed elements (SINEs). Several genes are targets of an alternative transcription factor IIIB (TFIIIB) containing Brf2 instead of Brf1 and have extremely low levels of TFIIIC. Strikingly, expressed Pol III genes, unlike nonexpressed Pol III genes, are situated in regions with a pattern of histone modifications associated with functional Pol II promoters. TFIIIC alone associates with numerous ETC loci, via the B box or a novel motif. ETCs are often near CTCF binding sites, suggesting a potential role in chromosome organization. Our results suggest that human Pol III complexes associate preferentially with regions near functional Pol II promoters and that TFIIIC-mediated recruitment of TFIIIB is regulated in a locus-specific manner.
Moqtaderi
Zarmik
Z
Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts, USA.
Wang
Jie
J
Raha
Debasish
D
White
Robert J
RJ
Snyder
Michael
M
Weng
Zhiping
Z
Struhl
Kevin
K
D001483:Base Sequence; D002460:Cell Line; D004257:DNA Polymerase II / Q000235:genetics; D056426:Genetic Loci; D015894:Genome, Human; D006801:Humans; D011401:Promoter Regions, Genetic; D012320:RNA Polymerase III / Q000235:genetics* / Q000378:metabolism*; D035381:TATA-Binding Protein Associated Factors / Q000235:genetics; D035361:Transcription Factor TFIIIB / Q000235:genetics; D014157:Transcription Factors / Q000235:genetics*; D019474:Transcription Factors, TFIII / Q000235:genetics; D000098832:Transcription Factor TFIIIC
C441028:BRF1 protein, human; C416185:BRF2 protein, human; D035381:TATA-Binding Protein Associated Factors; D035361:Transcription Factor TFIIIB; D014157:Transcription Factors; D019474:Transcription Factors, TFIII; D000098832:Transcription Factor TFIIIC; D012320:RNA Polymerase III; D004257:DNA Polymerase II