[Mechanism of transcription regulation by RNA polymerase II pausing]

For many years, the recruitment of Pol II to promoter region was considered to be the key step in the regulation of transcription. However, Pol II complex was then detected at the promoters of transcriptionally inactive genes. On that kind of genes, transcription regulation is realized by stimulation of promoter bound complex transition into the elongation phase. The available data concerning phenomenon of the transcription regulation by RNA polymerase II pausing mechanism are summarized in the current review. Here we discuss both the detailed mechanism of this process, which was studied in the model of heat shock genes in Drosophila, and some new data obtained from genome-wide studies. Hypotheses concerning functional role of the genes transcriptional regulation by RNA polymerase pausing mechanism are suggested.