[Analysis of soluble nuclear fractions regulating RNA synthesis]

The influence of the rat liver nuclear extract on RNA synthesis in the system of isolated cell nuclei of the rat liver was investigated. Two factors were discovered with opposite influence on RNA synthesis: one stimulating, while the other inhibiting the synthesis. A fraction of high-polymeric RNA (7-9 S) and a fraction of the total protein were isolated from the extract. The influence of these fractions on the transcription process was studied both in isolated nuclei and in the system containing pure liver DNA in the presence of RNA polymerase of E. coli. In both the cases the total fraction of protein turned out to stimulate RNA synthesis, while the high-polymeric fraction of RNA inhibited it. The soluble fractions, detected in the cells and influencing RNA synthesis, interact with RNA polymerase either increasing or decreasing the activity of the enzyme.