scholarly journals Stimulation of ribonucleic acid polymerase activity in vitro by prostatic steroid–protein receptor complexes

1973 ◽  
Vol 136 (3) ◽  
pp. 611-622 ◽  
Author(s):  
P. Davies ◽  
K. Griffiths
Keyword(s):  
Ionic Strength ◽  
Rna Polymerase ◽  
Polymerase Activity ◽  
Supernatant Fraction ◽  
Nuclear Fraction ◽  
Receptor Complexes ◽  
Protein Receptor ◽  
Ammonium Sulphate Fractionation ◽  
Stimulation Of

A system has been developed which allows the stimulation in vitro of prostatic RNA polymerase by prostatic 5α-dihydrotestosterone–protein receptor complexes prepared from the tissues of castrated rats. The reconstitution in vitro of such a system necessitates the purification of several subcellular components. Two 5α-dihydrotestosterone–receptor complexes are located in the prostatic soluble supernatant fraction, separable by selective ammonium sulphate fractionation, and one complex can be isolated from the nuclear fraction. In the presence of all these complexes, stimulation of RNA polymerase in intact nuclei and nucleoli was observed. The complexes also increased the activity of the enzyme solubilized from whole nuclei. Greater stimulation of this system was noted in the presence of prostatic chromatin as template, as compared with that observed with calf thymus DNA or liver chromatin as template. The effects of the complexes on subnuclear forms of RNA polymerase, of nucleolar and extranucleolar origin, are also described. RNA polymerase solubilized from nucleoli is more susceptible to stimulation by the 5α-dihydrotestosterone–receptor complexes than is the ‘nucleoplasmic’ enzyme. Stimulation occurs less readily in the presence of Mn2+and at high ionic strength than in the presence of Mg2+and at low ionic strength. Preliminary experiments show that prostatic nucleolar RNA polymerase transcribes prostatic chromatin poorly as compared with the nucleoplasmic enzyme. The observations reported indicate an involvement of non-histone proteins associated with DNA in the process by which stimulation of enzyme activity by the 5α-dihydrotestosterone–receptor complexes is achieved. The implications of these findings in the mechanism of steroid hormone action is considered.

scholarly journals Effects of α-amanitin on the stimulation of prostatic ribonucleic acid polymerase by prostatic steroid–protein receptor complexes

1974 ◽  
Vol 140 (3) ◽  
pp. 565-567 ◽  
Author(s):  
P. Davies ◽  
K. Griffiths
Keyword(s):  
Ionic Strength ◽  
Rna Polymerase ◽  
Ribonucleic Acid ◽  
Selective Inhibitor ◽  
High Ionic Strength ◽  
Receptor Complexes ◽  
Protein Receptor ◽  
Stimulation Of

Stimulation of prostatic RNA polymerase in vitro by prostatic 17β-hydroxy-5α-androstan-3-one (5α-dihydrotestosterone)–receptor complexes has been previously reported. By use of the selective inhibitor, α-amanitin, we have shown that both nucleolar and extranucleolar RNA polymerase activities may be stimulated, but stimulation is abolished at high ionic strength.

FURTHER STUDIES ON THE STIMULATION OF PROSTATIC RIBONUCLEIC ACID POLYMERASE BY 5α-DIHYDROTESTOSTERONE—RECEPTOR COMPLEXES

1974 ◽  
Vol 62 (2) ◽  
pp. 385-400 ◽  
Author(s):  
PETER DAVIES ◽  
KEITH GRIFFITHS
Keyword(s):  
Rna Polymerase ◽  
Active Form ◽  
Polymerase Activity ◽  
Selective Inhibitor ◽  
High Ionic Strength ◽  
Receptor Complexes ◽  
Associated Proteins ◽  
Rna Polymerase Activity ◽  
Stimulation Of

SUMMARY The stimulation in vitro of prostatic RNA polymerase activity by prostatic 5α-dihydrotestosterone—receptor complexes has been previously reported. Further investigations into the nature of the stimulation have now been carried out. By use of the selective inhibitor, α-amanitin, and by varying the concentration of ammonium sulphate in the assay media, both the nucleolar and extranucleolar forms of RNA polymerase could be stimulated, depending upon the ionic conditions employed. High ionic strength inhibited stimulation, either by interference with the association between steroid—receptor complexes and chromatin components, or by blocking the conversion of cytoplasmic complexes to a more 'active' form of the complex. 5α-Dihydrotestosterone—receptor complexes appeared to affect the template availability of prostatic chromatin, possibly in a way similar to that of the chromatin-associated proteins.

RNA polymerase activity in virions from Ustilago maydis

1984 ◽  
Vol 4 (1) ◽  
pp. 188-194
Author(s):  
B S Ben-Tzvi ◽  
Y Koltin ◽  
M Mevarech ◽  
A Tamarkin
Keyword(s):  
Rna Polymerase ◽  
Viral Genome ◽  
Ustilago Maydis ◽  
Polymerase Activity ◽  
Reaction Products ◽  
Double Stranded Rna ◽  
Rna Molecules ◽  
Rna Transcripts ◽  
Rna Polymerase Activity

RNA polymerase activity is associated with the double-stranded RNA virions of Ustilago maydis. The reaction products of the polymerase activity are single-stranded RNA molecules. The RNA molecules synthesized are homologous to the three classes of double-stranded RNA molecules that typify the viral genome. The single-stranded RNA synthesized is released from the virions. The molecular weight of the single-stranded RNA transcripts is about half the size of the double-stranded RNA segments, and thus, it appears that in the in vitro reaction, full-length transcripts can be obtained.

scholarly journals Thermolabile L-A virus-like particles from pet18 mutants of Saccharomyces cerevisiae.

1986 ◽  
Vol 6 (2) ◽  
pp. 404-410 ◽  
Author(s):  
T Fujimura ◽  
R B Wickner
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Rna Polymerase ◽  
Polymerase Activity ◽  
Nonpermissive Temperature ◽  
Wild Type ◽  
Rna Dependent Rna Polymerase ◽  
Virus Like Particles ◽  
Rna Polymerase Activity ◽  
Lines Of Evidence

pet18 mutations in Saccharomyces cerevisiae confer on the cell the inability to maintain either L-A or M double-stranded RNAs (dsRNAs) at the nonpermissive temperature. In in vitro experiments, we examined the effects of pet18 mutations on the RNA-dependent RNA polymerase activity associated with virus-like particles (VLPs). pet18 mutations caused thermolabile RNA polymerase activity of L-A VLPs, and this thermolability was found to be due to the instability of the L-A VLP structure. The pet18 mutations did not affect RNA polymerase activity of M VLPs. Furthermore, the temperature sensitivity of wild-type L-A RNA polymerase differed substantially from that of M RNA polymerase. From these results, and from other genetic and biochemical lines of evidence which suggest that replication of M dsRNA requires the presence of L-A dsRNA, we propose that the primary effect of the pet18 mutation is on the L-A VLP structure and that the inability of pet18 mutants to maintain M dsRNA comes from the loss of L-A dsRNA.

scholarly journals RNA polymerase activity in virions from Ustilago maydis.

1984 ◽  
Vol 4 (1) ◽  
pp. 188-194 ◽  
Author(s):  
B S Ben-Tzvi ◽  
Y Koltin ◽  
M Mevarech ◽  
A Tamarkin
Keyword(s):  
Rna Polymerase ◽  
Viral Genome ◽  
Ustilago Maydis ◽  
Polymerase Activity ◽  
Reaction Products ◽  
Double Stranded Rna ◽  
Rna Molecules ◽  
Rna Transcripts ◽  
Rna Polymerase Activity

RNA polymerase activity is associated with the double-stranded RNA virions of Ustilago maydis. The reaction products of the polymerase activity are single-stranded RNA molecules. The RNA molecules synthesized are homologous to the three classes of double-stranded RNA molecules that typify the viral genome. The single-stranded RNA synthesized is released from the virions. The molecular weight of the single-stranded RNA transcripts is about half the size of the double-stranded RNA segments, and thus, it appears that in the in vitro reaction, full-length transcripts can be obtained.

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