Heat-Shock-Specific Phosphorylation and Transcriptional Activity of RNA Polymerase II

1998 ◽  
Vol 242 (1) ◽  
pp. 211-221 ◽  
Author(s):  
E. Egyházi ◽  
A. Ossoinak ◽  
J.M. Lee ◽  
A.L. Greenleaf ◽  
T.P. Mäkelä ◽  
...  
1999 ◽  
Vol 77 (4) ◽  
pp. 367-374 ◽  
Author(s):  
Sébastien B Lavoie ◽  
Alexandra L Albert ◽  
Alain Thibodeau ◽  
Michel Vincent

The phosphorylation of the carboxy-terminal domain of the largest subunit of RNA polymerase II plays an important role in the regulation of transcriptional activity and is also implicated in pre-mRNA processing. Different stresses, such as a heat shock, induce a marked alteration in the phosphorylation of this domain. The expression of stress genes by RNA polymerase II, to the detriment of other genes, could be attributable to such modifications of the phosphorylation sites. Using two phosphodependent antibodies recognizing distinct hyperphosphorylated forms of RNA polymerase II largest subunit, we studied the phosphorylation state of the subunit in different species after heat shocks of varying intensities. One of these antibodies, CC-3, preferentially recognizes the carboxy-terminal domain of the largest subunit under normal conditions, but its reactivity is diminished during stress. In contrast, the other antibody used, MPM-2, demonstrated a strong reactivity after a heat shock in most species studied. Therefore, CC-3 and MPM-2 antibodies discriminate between phosphoisomers that may be functionally different. Our results further indicate that the pattern of phosphorylation of RNA polymerase II in most species varies in response to environmental stress.Key words: RNA polymerase II, heat shock, phosphorylation, CC-3, MPM-2.


2014 ◽  
Vol 25 (14) ◽  
pp. 2190-2198 ◽  
Author(s):  
Tim Patrick Kaminski ◽  
Jan Peter Siebrasse ◽  
Ulrich Kubitscheck

Regulation of RNA polymerase II (RNAPII) during transcription is essential for controlling gene expression. Here we report that the transcriptional activity of RNAPII at the Balbiani ring 2.1 gene could be halted during stable elongation in salivary gland cells of Chironomus tentans larvae for extended time periods in a regulated manner. The transcription halt was triggered by heat shock and affected all RNAPII independently of their position in the gene. During the halt, incomplete transcripts and RNAPII remained at the transcription site, the phosphorylation state of RNAPII was unaltered, and the transcription bubbles remained open. The transcription of halted transcripts was resumed upon relief of the heat shock. The observed mechanism allows cells to interrupt transcription for extended time periods and rapidly reactivate it without the need to reinitiate transcription of the complete gene. Our results suggest a so-far-unknown level of transcriptional control in eukaryotic cells.


1995 ◽  
Vol 129 (2) ◽  
pp. 287-298 ◽  
Author(s):  
D B Bregman ◽  
L Du ◽  
S van der Zee ◽  
S L Warren

A subpopulation of the largest subunit of RNA polymerase II (Pol II LS) is located in 20-50 discrete subnuclear domains that are closely linked to speckle domains, which store splicing proteins. The speckle-associated fraction of Pol II LS is hyperphosphorylated on the COOH-terminal domain (CTD), and it is highly resistant to extraction by detergents. A diffuse nucleoplasmic fraction of Pol II LS is relatively hypophosphorylated on the CTD, and it is easily extracted by detergents. In transcriptionally active nuclei, speckle bound hyperphosphorylated Pol II LS molecules are distributed in irregularly shaped speckle domains, which appear to be interconnected via a reticular network. When transcription is inhibited, hyperphosphorylated Pol II LS and splicing protein SC35 accumulate in speckle domains, which are transformed into enlarged, dot-like structures lacking interconnections. When cells are released from transcriptional inhibition, Pol IIO and SC35 redistribute back to the interconnected speckle pattern of transcriptionally active cells. The redistribution of Pol II and SC35 is synchronous, reversible, and temperature dependent. It is concluded that: (a) hyperphosphorylation of Pol II LS's CTD is a better indicator of its tight association to discrete subnuclear domains than its transcriptional activity; (b) during states of transcriptional inhibition, hyperphosphorylated Pol II LS can be stored in enlarged speckle domains, which under the light microscope appear to coincide with the storage sites for splicing proteins; and (c) Pol II and splicing proteins redistribute simultaneously according to the overall transcriptional activity of the nucleus.


1997 ◽  
Vol 25 (4) ◽  
pp. 694-700 ◽  
Author(s):  
M.-F. Dubois ◽  
M. Vincent ◽  
M. Vigneron ◽  
J. Adamczewski ◽  
J.-M. Egly ◽  
...  

2012 ◽  
Vol 32 (17) ◽  
pp. 3428-3437 ◽  
Author(s):  
N. J. Fuda ◽  
M. S. Buckley ◽  
W. Wei ◽  
L. J. Core ◽  
C. T. Waters ◽  
...  

1993 ◽  
Vol 13 (6) ◽  
pp. 3456-3463 ◽  
Author(s):  
T O'Brien ◽  
J T Lis

Heat shock rapidly activates expression of some genes and represses others. The kinetics of changes in RNA polymerase distribution on heat shock-modulated genes provides a framework for evaluating the mechanisms of activation and repression of transcription. Here, using two methods, we examined the changes in RNA polymerase II association on a set of Drosophila genes at 30-s intervals following an instantaneous heat shock. In the first method, Drosophila Schneider line 2 cells were quickly frozen to halt transcription, and polymerase distribution was analyzed by a nuclear run-on assay. RNA polymerase transcription at the 5' end of the hsp70 gene could be detected within 30 to 60 s of induction, and by 120 s the first wave of polymerase could already be detected near the 3' end of the gene. A similar rapid induction was found for the small heat shock genes (hsp22, hsp23, hsp26, and hsp27). In contrast to this rapid activation, transcription of the histone H1 gene was found to be rapidly repressed, with transcription reduced by approximately 90% within 300 s of heat shock. Similar results were obtained by an in vivo UV cross-linking assay. In this second method, cell samples removed at 30-s intervals were irradiated with 40-microseconds bursts of UV light from a Xenon flash lamp, and the distribution of polymerase was examined by precipitating UV cross-linked protein-DNA complexes with an antibody to RNA polymerase II. Both approaches also showed the in vivo rate of movement of the first wave of RNA polymerase through the hsp70 gene to be approximately 1.2 kb/min.


1988 ◽  
Vol 66 (11) ◽  
pp. 1177-1185 ◽  
Author(s):  
D. Barettino ◽  
G. Morcillo ◽  
J. L. Díez ◽  
M. T. Carretero ◽  
M. J. Carmona

The induction of puff III-A3b, a major heat-shock puff in Chironomus thummi salivary cells, was insensitive to the transcription inhibitor 5,6-dichloro-1-β-D-ribofuranosylbenzimidazole (DRB), whereas no transcriptional activity could be detected at the other heat-shock puffs in the presence of this drug. In these conditions, a polypeptide with the same Mr and isoform pattern as those of the major heat-shock polypeptide, hsp70, was synthesized. These results suggest that hsp70 is encoded by locus III-A3b. In addition to DRB insensitivity, incorporation of [3H]UTP on puff III-A3b took place in an in vitro transcription assay under low-salt conditions (100 mM NaCl); no labelling could be detected at the other heat-shock puffs under these conditions. Although DRB has been reported as a specific inhibitor of RNA polymerase II-directed transcription, and although the low-salt conditions were not propitious for the activity of this enzyme, RNA polymerase II was detected on puff III-A3b and on the other heat-shock puffs by immunofluorescence with anti-RNA polymerase II antibodies.


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