CTDP1 and RPB7 stabilize and license Pol II termination to reinitiation [Micro-C]
The regulations of RNA Pol II initiation, elongation, and termination have been extensively investigated in mammalian cells, but how RNA Pol II terminates and then reinitiates a new round of transcription remains elusive. Here, we found that RPB7 loss triggers the degradation of RNA Pol II. Strikingly, RPB7 degradation combines knock out of E3 ligase Cullin 3 led to the accumulation of phosphorylated Pol II in the soluble fractions and Pol II reinitiation failure. The stability of recycled Pol II is dependent on the loop domain of RPB7 and the dephosphorylation of Pol II CTD. Termination-reinitiation recycling requires RPB7, CTD phosphatase subunit 1 (CTDP1), and stabilization of Pol II. Our study demonstrates that RPB7/CTDP1 controls the dephosphorylation and stabilization of RNA Pol II to permit RNA Pol II termination to reinitiation recycle in mammalian cells. Overall design: Micro-C in CTDP1 degron cells.