[IIa/IIo conversion of RNA polymerase II during heat shock].
Heat-shock treatment of cells activates a protein kinase which phosphorylates a heptapeptide analogous to the repeated motif of the C-terminal domain (CTD) of the large subunit of RNA polymerase II from mammalian cells. This is corroborated with a modification of the large subunit of this enzyme during thermal stress in HeLa cells. We have observed a shift from the IIa form (unphosphorylated) to the IIo form (phosphorylated) with a higher apparent molecular weight, during a heat-shock at 44, 45 or 46 degrees C and by a chemical stress induced by sodium arsenite. RNA polymerase II hyperphosphorylation, together with the activation of the heat-shock transcription factor, might contribute to the onset of the preferential transcription of heat-shock genes.
Dubois
M F
MF
Groupe de Biologie moléculaire du Stress, Ecole normale supérieure, Paris.
Bensaude
O
O
Morange
M
M
D001149:Arsenates / Q000494:pharmacology; D006367:HeLa Cells; D006358:Hot Temperature / Q000009:adverse effects*; D006801:Humans; D010766:Phosphorylation / Q000187:drug effects; D012319:RNA Polymerase II / Q000378:metabolism* / Q000493:pharmacokinetics
D001149:Arsenates; D012319:RNA Polymerase II
Conversion IIa/IIo de l'ARN polymérase II pendant le choc thermique.