Super Elongation Complex (SEC) and global genomic analyses in murine embryonic stem (ES) cells and in human cells in response to activation signals.

Transcriptional regulation of developmentally controlled genes is at the heart of differentiation and organogenesis. In this study, we have performed global genomic analyses in murine embryonic stem (ES) cells and in human cells in response to activation signals. We have identified an essential role for the ELL/P-TEFbcontaining Super Elongation Complex (SEC) in the regulation of gene expression including several genes bearing paused RNA polymerase II (Pol II). Paused Pol II has been proposed to be associated with loci that respond rapidly to environmental stimuli. However, our studies in ES cells have also identified a requirement for SEC at genes without preloaded Pol II, which also respond dynamically to differentiation signals. Our findings suggest that SEC is a major class of active P-TEFb-containing complexes required for transcriptional activation in response to environmental cues such as differentiation signals. Examination of ELL2, AFF4, and Pol II before and after activation signals in two cell types.