Activation of Nuclear RNA Polymerase by Sarkosyl

Abstract

Treatment of mouse nuclei with the anionic detergent, sarkosyl, causes a several‐fold enhancement of endogenous RNA polymerase activity. The stimulatory effect of sarkosyl is due to two factors: a two‐fold increase in the initial activity of RNA polymerase II, and a prolongation of the total RNA polymerase reaction. Inhibition of RNase by sarkosyl could not account for either of these effects. Whereas sarkosyl and ammonium sulfate both stimulate RNA polymerase II, the effects are non‐additive, The RNA synthesized in the presence of sarkosyl sedimented primarily at 16‐23 S. whereas in the absence of detergent the RNA sedimented at 4–5 S. Sarkosyl caused the release of nearly all of the protein from cellular DNA, but apparently did not release initiated RNA polymerase. The stimulatory effect of sarkosyl on the initial rate of RNA synthesis catalyzed by RNA polymerase II can be explained by either of two extreme alternatives, or some combination of them. Either 50% of the enzyme is present in a totally repressed state, or all of the enzyme is partially inhibited by protein or other sarkosyl‐sensitive material. Copyright © 1975, Wiley Blackwell. All rights reserved