Premature termination of transcription by RNAP II

Abstract

T ranscription elongation is now rec-ognized as an important mechanism of gene regulation in eukaryotes. A large number of genes undergo an early step in transcription that is rate limiting for expression. Genome-wide studies show-ing that RNA polymerase II accumulates to high densities near the promoters of many genes has led to the idea that pro-moter-proximal pausing of transcription is a widespread, rate-limiting step in early elongation. Recent evidence sug-gests that much of this paused RNA polymerase II is competent for transcrip-tion elongation. Here, we discuss recent studies suggesting that RNA polymerase II that accumulates nearby the promoter of a subset of genes is undergoing prema-ture termination of transcription.