A role for Yin Yang-1 (YY1) in the assembly of snRNA transcription complexes.
The RNA polymerase (pol) II and III human small nuclear RNA (snRNA) genes have very similar promoters and recruit a number of common factors. In particular, both types of promoters utilize the small nuclear RNA activating protein complex (SNAP(c)) and the TATA box binding protein (TBP) for basal transcription, and are activated by Oct-1. We find that SNAP(c) purified from cell lines expressing tagged SNAP(c) subunits is associated with Yin Yang-1 (YY1), a factor implicated in both activation and repression of transcription. Recombinant YY1 accelerates the binding of SNAP(c) to the proximal sequence element, its target within snRNA promoters. Moreover, it enhances the formation of a complex on the pol III U6 snRNA promoter containing all the factors (SNAP(c), TBP, TFIIB-related factor 2 (Brf2), and B double prime 1 (Bdp1)) that are sufficient to direct in vitro U6 transcription when complemented with purified pol III, as well as that of a subcomplex containing TBP, Brf2, and Bdp1. YY1 is found on both the RNA polymerase II U1 and the RNA polymerase III U6 promoters as determined by chromatin immunoprecipitations. Thus, YY1 represents a new factor that participates in transcription complexes formed on both pol II and III promoters.
Emran
Farida
F
Stony Brook University, Graduate Program in Molecular and Cellular Pharmacology, Stony Brook, NY 11794, USA.
Florens
Laurence
L
Ma
Beicong
B
Swanson
Selene K
SK
Washburn
Michael P
MP
Hernandez
Nouria
N
D000818:Animals; D001665:Binding Sites / Q000235:genetics; D004247:DNA / Q000235:genetics / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D051379:Mice; D046912:Multiprotein Complexes; D011401:Promoter Regions, Genetic; D012342:RNA, Small Nuclear / Q000235:genetics* / Q000378:metabolism*; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism*; D014158:Transcription, Genetic; D050986:YY1 Transcription Factor / Q000235:genetics / Q000378:metabolism*
D046912:Multiprotein Complexes; D012342:RNA, Small Nuclear; D011994:Recombinant Proteins; C106703:SNAPC protein complex, human; C099437:SNAPC2 protein, human; D014157:Transcription Factors; C405483:U1 small nuclear RNA; C405486:U6 small nuclear RNA; D050986:YY1 Transcription Factor; C494698:YY1 protein, human; D004247:DNA