The objectives of this research are: (a)\to determine whether the protein kinase closely associated with RNA polymerase I is structurally related to the NII protein kinase; (b)\to investigate whether the protein kinase from the tumor is distinct from the corresponding liver enzyme; (c)\to examine the probable role of the NII kinase and of RNA polymerase\I phosphorylation on ribosomal gene transcription; (d)\to investigate whether the augmented protein kinase activity is due to increased amount of the enzyme and to elevated level of translatable mRNA for the kinase; and (e)\to explore the possibility that the NII protein kinase is involved in cell growth. During the coming year we will complete studies on the peptide mapping of RNA polymerase I polypeptides (42 and 25 kilodaltons) and of NII protein kinase of similar molecular weights. This will establish the structural relationship of the two polymerase I polypeptides and the kinase and demonstrate that the protein kinase activity associated with highly purified RNA polymerase I from rapidly growing tissues such as a rat hepatoma is an integral part of the core RNA polymerase I. We will also investigate the effect of purified NII protein kinase on cloned rDNA (truncated template containing the correct initiation site) on transcription in vitro using cell lysates. The cell lysate will then be fractionated to identify the factor(s) involved in regulating the transcription of rDNA. The effect of NII kinase and phosphorylated RNA polymerase in this reaction will be investigated using a fractionated cell extract which is devoid of NII kinase and RNA polymerase I.