Isolation of transcription factors that discriminate between different promoters recognized by RNA polymerase II

摘要: A new fractionation procedure separates a whole-cell HeLa extract into three components required for accurate in vitro transcription. One component (Sp1) is promoter-specific factor transcription of the SV40 early and late promoters, but not other promoters we have tested. The second (Sp2) general series others, including adeno-virus 2 major promoter, human beta-globin promoter avian sarcoma virus promoter. third fraction containing endogenous RNA polymerase II. When adenovirus templates were present simultaneously an reaction, addition Sp1 stimulated 40-fold, inhibited by 40%. This finding suggests that involved selection, merely stimulatory factor.