DNA-dependent RNA polymerase II (EC 2.7.7.6), a complex multisubunit enzyme, is responsible for the transcription of protein-coding genes. It is composed of 10 to 14 subunits ranging in size from 220 to 10 kD.
This complex interacts with the promoter regions of genes as well as with a variety of elements and transcription factors to determine essentially all of the parameters that govern transcription, e.g., tissue and development specificity, stress response, etc.
A fraction of the large subunit of Pol II (Pol II LS) is ubiquitinated after exposing cells to UV radiation or cisplatin