Imaging transcription elongation dynamics by new technologies unveils the organization of initiation and elongation in transcription factories

In mammalian cells, RNA polymerase II (RNAP2)-mediated transcription occurs in numerous foci in the nucleus. Transcription foci detected by RNAP2 activity have often been called transcription factories. Recent super-resolution microscopy techniques have revealed clustering and focus formation of RNAP2 in living cells, depending on phosphorylation states of repeats in its C-terminal domain (CTD). The differentially phosphorylated initiation and processive elongation forms of RNAP2 have also been tracked using live-cell probes derived from phosphorylation-specific antibodies. Recent live cell observations have detected spatially separated initiation and elongating RNAP2 foci, suggesting the presence of transcription initiation and elongation factories.

Automated summary

Recent advances in microscopy techniques have revealed the formation of transcription foci by RNA polymerase II (RNAP2) in the nucleus, which depend on its phosphorylation states. Spatially separated initiation and elongation foci have also been observed, suggesting the presence of transcription initiation and elongation factories.