Fig. 9.

DNA–RNA hybrid traps RNA Polymerase II on chromatin. a Depletion of SFPQ and SF3B3 causes retention of RNA Pol II on chromatin that is released by treatment with RNAseH1. Western blot of soluble (cytoplasmic) and insoluble (pellet) fractions of nuclear extracts prepared from HeLa cells that were knocked down with siRNAs against the indicated genes. Blots were also probed for GAPDH and LaminA to validate cytoplasmic and chromatin pellet fractions, respectively. b As in a showing that knockdown of DHX9 in cells depleted of SFPQ reverses the retention of RNA Pol II S2P on chromatin. c RNA Pol II (S2P) is not retained in the insoluble chromatin pellet from cells knocked down for XRN2