Inhibition of nuclear DNA-dependent RNA polymerases from mouse ascites tumors and liver by glycerol

1977 ◽  
Vol 55 (10) ◽  
pp. 1117-1120 ◽  
Author(s):  
D. G. R. Blair
Keyword(s):  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Mouse Liver ◽  
Nuclear Dna ◽  
Ehrlich Ascites Carcinoma ◽  
Rna Polymerases ◽  
Ehrlich Carcinoma ◽  
Ehrlich Ascites ◽  
Mouse Ascites ◽  
Ascites Tumors

Nuclear DNA-dependent RNA polymerases were isolated from Ehrlich ascites carcinoma, TA3 ascites adenocarcinoma, and mouse liver and tested for inhibition by glycerol. The results confirm the finding of Smith and Duerksen ((1975) Biochem. Biophys. Res. Commun. 67, 916–923) that glycerol may inhibit nuclear RNA polymerase II, but because different grades of glycerol inhibited mouse liver RNA polymerase IIa to different extents, it is suggested that an inhibitory contaminant is present. RNA polymerases IIa and IIb from the two tumors and mouse liver were proportionately inhibited by A.C.S. reagent-grade glycerol at concentrations above 10%. RNA polymerase Ia from liver and the TA3 tumor was not inhibited by any concentration of glycerol tested (2–32.3%), but RNA polymerase Ia from Ehrlich carcinoma was inhibited by glycerol concentrations above 16%.

scholarly journals Loss of the Rpb4/Rpb7 Subcomplex in a Mutant Form of the Rpb6 Subunit Shared by RNA Polymerases I, II, and III

2003 ◽  
Vol 23 (9) ◽  
pp. 3329-3338 ◽  
Author(s):  
Qian Tan ◽  
Meredith H. Prysak ◽  
Nancy A. Woychik
Keyword(s):  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Rna Polymerases ◽  
Mutant Form ◽  
Direct Association ◽  
Before And After ◽  
Polymerase I ◽  
Conserved Core ◽  
Mutant Cells ◽  
Regulation Of Enzyme Activity

ABSTRACT We have identified a conditional mutation in the shared Rpb6 subunit, assembled in RNA polymerases I, II, and III, that illuminated a new role that is independent of its assembly function. RNA polymerase II and III activities were significantly reduced in mutant cells before and after the shift to nonpermissive temperature. In contrast, RNA polymerase I was marginally affected. Although the Rpb6 mutant strain contained two mutations (P75S and Q100R), the majority of growth and transcription defects originated from substitution of an amino acid nearly identical in all eukaryotic counterparts as well as bacterial ω subunits (Q100R). Purification of mutant RNA polymerase II revealed that two subunits, Rpb4 and Rpb7, are selectively lost in mutant cells. Rpb4 and Rpb7 are present at substoichiometric levels, form a dissociable subcomplex, are required for RNA polymerase II activity at high temperatures, and have been implicated in the regulation of enzyme activity. Interaction experiments support a direct association between the Rpb6 and Rpb4 subunits, indicating that Rpb6 is one point of contact between the Rpb4/Rpb7 subcomplex and RNA polymerase II. The association of Rpb4/Rpb7 with Rpb6 suggests that analogous subunits of each RNA polymerase impart class-specific functions through a conserved core subunit.

scholarly journals The Perinucleolar Compartment and Transcription

1998 ◽  
Vol 143 (1) ◽  
pp. 35-47 ◽  
Author(s):  
Sui Huang ◽  
Thomas J. Deerinck ◽  
Mark H. Ellisman ◽  
David L. Spector
Keyword(s):  
Nucleic Acids ◽  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Rna Polymerase Iii ◽  
Selective Inhibition ◽  
Rna Polymerases ◽  
Double Labeling ◽  
Polypyrimidine Tract Binding Protein ◽  
Cell Biol ◽  
Perinucleolar Compartment

The perinucleolar compartment (PNC) is a unique nuclear structure localized at the periphery of the nucleolus. Several small RNAs transcribed by RNA polymerase III and two hnRNP proteins have been localized in the PNC (Ghetti, A., S. Piñol-Roma, W.M. Michael, C. Morandi, and G. Dreyfuss. 1992. Nucleic Acids Res. 20:3671–3678; Matera, A.G., M.R. Frey, K. Margelot, and S.L. Wolin. 1995. J. Cell Biol. 129:1181– 1193; Timchenko, L.T., J.W. Miller, N.A. Timchenko, D.R. DeVore, K.V. Datar, L. Lin, R. Roberts, C.T. Caskey, and M.S. Swanson. 1996. Nucleic Acids Res. 24: 4407–4414; Huang, S., T. Deerinck, M.H. Ellisman, and D.L. Spector. 1997. J. Cell Biol. 137:965–974). In this report, we show that the PNC incorporates Br-UTP and FITC-conjugated CTP within 5 min of pulse labeling. Selective inhibition of RNA polymerase I does not appreciably affect the nucleotide incorporation in the PNC. Inhibition of all RNA polymerases by actinomycin D blocks the incorporation completely, suggesting that Br-UTP incorporation in the PNC is due to transcription by RNA polymerases II and/or III. Treatment of cells with an RNA polymerase II and III inhibitor induces a significant reorganization of the PNC. In addition, double labeling experiments showed that poly(A) RNA and some of the factors required for pre-mRNA processing were localized in the PNC in addition to being distributed in their previously characterized nucleoplasmic domains. Fluorescence recovery after photobleaching (FRAP) analysis revealed a rapid turnover of polypyrimidine tract binding protein within the PNC, demonstrating the dynamic nature of the structure. Together, these findings suggest that the PNC is a functional compartment involved in RNA metabolism in the cell nucleus.

Purification and preparation of antibody to RNA polymerase II stimulatory factors from Ehrlich ascites tumor cells

Biochemistry ◽  
1979 ◽  
Vol 18 (8) ◽  
pp. 1582-1588 ◽  
Author(s):  
Kazuhisa Sekimizu ◽  
Yoshinobu Nakanishi ◽  
Den'ichi Mizuno ◽  
Shunji Natori
Keyword(s):  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Tumor Cells ◽  
Ehrlich Ascites Tumor ◽  
Ehrlich Ascites Tumor Cells ◽  
Ascites Tumor ◽  
Ehrlich Ascites

NTP-driven translocation and regulation of downstream template opening by multi-subunit RNA polymerases

2005 ◽  
Vol 83 (4) ◽  
pp. 486-496 ◽  
Author(s):  
Zachary F Burton ◽  
Michael Feig ◽  
Xue Q Gong ◽  
Chunfen Zhang ◽  
Yuri A Nedialkov ◽  
...  
Keyword(s):  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Active Site ◽  
Binding Sites ◽  
Rna Synthesis ◽  
Rna Polymerases ◽  
Phosphoryl Transfer ◽  
Elongation Complex ◽  
Detailed Model ◽  
Loop 2

Multi-subunit RNA polymerases bind nucleotide triphosphate (NTP) substrates in the pretranslocated state and carry the dNMP–NTP base pair into the active site for phosphoryl transfer. NTP-driven translocation requires that NTP substrates enter the main-enzyme channel before loading into the active site. Based on this model, a new view of fidelity and efficiency of RNA synthesis is proposed. The model predicts that, during processive elongation, NTP-driven translocation is coupled to a protein conformational change that allows pyrophosphate release: coupling the end of one bond-addition cycle to substrate loading and translocation for the next. We present a detailed model of the RNA polymerase II elongation complex based on 2 low-affinity NTP binding sites located in the main-enzyme channel. This model posits that NTP substrates, elongation factors, and the conserved Rpb2 subunit fork loop 2 cooperate to regulate opening of the downstream transcription bubble.Key words: RNA polymerase, NTP-driven translocation, transcriptional fidelity, transcriptional efficiency, α-amanitin.

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