Regulation of RNA polymerase activity in liver and brain cell nuclei by a cytoplasmic thyroxine modulator in rats of various ages

1993 ◽  
Vol 116 (1) ◽  
pp. 820-822
Author(s):  
Ya. Kh. Turakulov ◽  
S. N. Dalimova ◽  
I. R. Kamalieva ◽  
G. D. Umarova ◽  
B. A. Atakhanova
1986 ◽  
Vol 41 (2) ◽  
pp. 372-377 ◽  
Author(s):  
Hanna Wiszkowska ◽  
Irena Kulamowicz ◽  
Alicja Malinowska ◽  
Zofia Walter

1985 ◽  
Vol 249 (2) ◽  
pp. H344-H350
Author(s):  
P. B. Taylor ◽  
Q. Tang

Myocardial and nonmyocardial cell nuclei were isolated from ventricles of adult male Wistar rats by means of sucrose density centrifugation. RNA polymerase activity in myocyte nuclei was approximately 80-90% higher than in nonmyocytes. Total myocyte chromatin template activity using Escherichia coli RNA polymerase was linear and about onefold greater than the nonmyocyte fraction over a fivefold range of chromatin concentrations. Preincubation time required for RNA polymerase to form a stable binding complex with chromatin was at least 40 min for myocyte and 30 min for nonmyocyte nuclear subsets. Titration of chromatin against a fixed amount of RNA polymerase (5 micrograms) showed that 5 micrograms of myocyte chromatin (as DNA) and 8 micrograms of nonmyocyte chromatin (as DNA), respectively, were required to saturate the enzyme. These results indicate that myocyte chromatin can support greater enzyme binding than can nonmyocyte chromatin. The distribution of DNA fragments from isolated myocyte and nonmyocyte nuclei were similar when alkaline sucrose density centrifugation was used. Chromatin prepared from these nuclear subsets showed no difference in degree of DNA fragmentation. These observations indicate that compared with nonmuscle cells, myocytes from adult rat hearts have higher RNA polymerase activity, greater overall chromatin template function, and higher binding capacity for RNA polymerase. Collectively, these data suggest that adult cardiac muscle cells should have a larger potential for RNA synthesis than nonmuscle cells.


1970 ◽  
Vol 48 (5) ◽  
pp. 559-565 ◽  
Author(s):  
R. S. D. Read ◽  
C. M. Mauritzen

The suitability of saponin for the isolation and of glycerol for the preservation of mammalian cell nuclei has been investigated. The nonionic detergent saponin was found to be a useful cell lytic agent in a procedure for the isolation of nuclei from several mammalian cell types. The RNA polymerase activity of rat liver nuclei was not affected by treatment with saponin or with some other nonionic detergents that were tested. Low concentrations of ionic agents also did not affect the activity of the enzyme though higher concentrations caused lysis of the nuclei. The preservation of structure and enzyme activity in the isolated nuclei was achieved by storage at low temperature in a medium containing 70% glycerol together with a suitable concentration of a divalent metal and phosphate buffer.


2021 ◽  
pp. molcanther.MCT-20-0489-A.2020
Author(s):  
Daniel A. R. Heisey ◽  
Sheeba Jacob ◽  
Timonthy L Lochmann ◽  
Richard Kurupi ◽  
Maninderjit S. Ghotra ◽  
...  

1984 ◽  
Vol 4 (1) ◽  
pp. 188-194
Author(s):  
B S Ben-Tzvi ◽  
Y Koltin ◽  
M Mevarech ◽  
A Tamarkin

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.


2018 ◽  
Vol 93 (4) ◽  
Author(s):  
Huan Chen ◽  
Yingjuan Qian ◽  
Xin Chen ◽  
Zhiyang Ruan ◽  
Yuetian Ye ◽  
...  

ABSTRACT The life cycle of influenza A virus (IAV) is modulated by various cellular host factors. Although previous studies indicated that IAV infection is controlled by HDAC6, the deacetylase involved in the regulation of PA remained unknown. Here, we demonstrate that HDAC6 acts as a negative regulator of IAV infection by destabilizing PA. HDAC6 binds to and deacetylates PA, thereby promoting the proteasomal degradation of PA. Based on mass spectrometric analysis, Lys(664) of PA can be deacetylated by HDAC6, and the residue is crucial for PA protein stability. The deacetylase activity of HDAC6 is required for anti-IAV activity, because IAV infection was enhanced due to elevated IAV RNA polymerase activity upon HDAC6 depletion and an HDAC6 deacetylase dead mutant (HDAC6-DM; H216A, H611A). Finally, we also demonstrate that overexpression of HDAC6 suppresses IAV RNA polymerase activity, but HDAC6-DM does not. Taken together, our findings provide initial evidence that HDAC6 plays a negative role in IAV RNA polymerase activity by deacetylating PA and thus restricts IAV RNA transcription and replication. IMPORTANCE Influenza A virus (IAV) continues to threaten global public health due to drug resistance and the emergence of frequently mutated strains. Thus, it is critical to find new strategies to control IAV infection. Here, we discover one host protein, HDAC6, that can inhibit viral RNA polymerase activity by deacetylating PA and thus suppresses virus RNA replication and transcription. Previously, it was reported that IAV can utilize the HDAC6-dependent aggresome formation mechanism to promote virus uncoating, but HDAC6-mediated deacetylation of α-tubulin inhibits viral protein trafficking at late stages of the virus life cycle. These findings together will contribute to a better understanding of the role of HDAC6 in regulating IAV infection. Understanding the molecular mechanisms of HDAC6 at various periods of viral infection may illuminate novel strategies for developing antiviral drugs.


1972 ◽  
Vol 11 (11) ◽  
pp. 3105-3110 ◽  
Author(s):  
J.F. Payne ◽  
Arya K. Bal

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