Polymerase I And Transcript Release Factor (PTRF)

PTRF encodes a protein that enables the dissociation of paused ternary polymerase I transcription complexes from the 3""" end of pre-rRNA transcripts. This protein regulates rRNA transcription by promoting the dissociation of transcription complexes and the reinitiation of polymerase I on nascent rRNA transcripts.This protein also localizes to caveolae at the plasma membrane and is thought to play a critical role in the formation of caveolae and the stabilization of caveolins. This protein translocates from caveolae to the cytoplasm after insulin stimulation. Caveolae contain truncated forms of this protein and may be the site of phosphorylation-dependent proteolysis. This protein is also thought to modify lipid metabolism and insulin-regulated gene expression.