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Inhibition of eukaryotic DNA-dependent RNA polymerase release from isolated nuclei and nucleoli by phenylmethylsulfonylfluoride

1975; Elsevier BV; Volume: 171; Issue: 1 Linguagem: Inglês

10.1016/0003-9861(75)90032-6

1096-0384

Thomas J. Lindell,

Synthesis and Biological Evaluation

Eukaryotic RNA polymerases are spontaneously released from nuclei and nucleoli after addition of a low concentration of ammonium sulfate. This release occurs even in the presence of hypertonic sucrose buffers that are known to prevent the loss of RNA polymerases from nuclei. Release of RNA polymerases is inhibited by the addition of a serine esterase inhibitor, phenylmethylsulfonylfluoride (PhMeSF), to suspensions of nuclei or nucleoli even in the presence of ammonium sulfate. GTP but not ATP is partially effective in preventing the release of RNA polymerase I from nucleoli isolated in the absence of PhMeSF. Studies of nuclear and nucleolar transcription indicate that there is a higher level of endogenous RNA polymerase activity in these organelles isolated in the presence of PhMeSF. When RNA polymerases are solubilized from paired nuclear and nucleolar samples isolated in the presence and absence of PhMeSF, the specific activity of RNA polymerases is higher when these enzymes are solubilized from these organelles isolated in the presence of this agent.