Changes in the transcriptional activity of barley plastome genes under heat shock

2008 ◽  
Vol 55 (3) ◽  
pp. 293-300 ◽  
Author(s):  
Ya. O. Zubo ◽  
E. A. Lysenko ◽  
A. Yu. Aleinikova ◽  
V. V. Kusnetsov ◽  
N. L. Pshibytko
1998 ◽  
Vol 18 (11) ◽  
pp. 6624-6633 ◽  
Author(s):  
Bin He ◽  
Yong-Hong Meng ◽  
Nahid F. Mivechi

ABSTRACT Heat shock transcription factor 1 (HSF-1) activates the transcription of heat shock genes in eukaryotes. Under normal physiological growth conditions, HSF-1 is a monomer. Its transcriptional activity is repressed by constitutive phosphorylation. Upon activation, HSF-1 forms trimers, acquires DNA binding activity, increases transcriptional activity, and appears as punctate granules in the nucleus. In this study, using bromouridine incorporation and confocal laser microscopy, we demonstrated that newly synthesized pre-mRNAs colocalize to the HSF-1 punctate granules after heat shock, suggesting that these granules are sites of transcription. We further present evidence that glycogen synthase kinase 3β (GSK-3β) and extracellular signal-regulated kinase mitogen-activated protein kinase (ERK MAPK) participate in the down regulation of HSF-1 transcriptional activity. Transient increases in the expression of GSK-3β facilitate the disappearance of HSF-1 punctate granules and reduce hsp-70 transcription after heat shock. We have also shown that ERK is the priming kinase for GSK-3β. Taken together, these results indicate that GSK-3β and ERK MAPK facilitate the inactivation of activated HSF-1 after heat shock by dispersing HSF-1 from the sites of transcription.


2004 ◽  
Vol 101 (12) ◽  
pp. 4100-4105 ◽  
Author(s):  
F. Boellmann ◽  
T. Guettouche ◽  
Y. Guo ◽  
M. Fenna ◽  
L. Mnayer ◽  
...  

2020 ◽  
Author(s):  
Wen-Cheng Lu ◽  
Ramsey Omari ◽  
Haimanti Ray ◽  
Richard L. Carpenter

AbstractThe heat stress response activates the transcription factor heat shock factor 1 (HSF1), which subsequently upregulates heat shock proteins to maintain the integrity of the proteome. HSF1 activity requires nuclear localization, trimerization, DNA binding, phosphorylation, and gene transactivation. Phosphorylation at S326 is an important regulator of HSF1 transcriptional activity. Phosphorylation at S326 is mediated by AKT1, mTOR, p38, and MEK1. mTOR, p38, and MEK1 all phosphorylated S326 but AKT1 was the more potent activator. Mass spectrometry showed that AKT1 phosphorylated HSF1 at T142, S230, and T527 in addition to S326 whereas the other kinases did not. Subsequent investigation revealed that phosphorylation at T142 is necessary for HSF1 trimerization and that S230, S326, and T527 are required for HSF1 gene transactivation and recruitment of TFIIB and CDK9. This study suggests that HSF1 activity is regulated by phosphorylation at specific residues that promote different stages of HSF1 activation. Furthermore, this is the first study to identify the functional role of these phosphorylation events.


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.


2007 ◽  
Vol 67 (21) ◽  
pp. 10455-10465 ◽  
Author(s):  
Amina Zoubeidi ◽  
Anousheh Zardan ◽  
Eliana Beraldi ◽  
Ladan Fazli ◽  
Richard Sowery ◽  
...  

2006 ◽  
Vol 17 (3) ◽  
pp. 1322-1330 ◽  
Author(s):  
Anna Tsapara ◽  
Karl Matter ◽  
Maria S. Balda

The tight junction adaptor protein ZO-1 regulates intracellular signaling and cell proliferation. Its Src homology 3 (SH3) domain is required for the regulation of proliferation and binds to the Y-box transcription factor ZO-1-associated nucleic acid binding protein (ZONAB). Binding of ZO-1 to ZONAB results in cytoplasmic sequestration and hence inhibition of ZONAB's transcriptional activity. Here, we identify a new binding partner of the SH3 domain that modulates ZO-1–ZONAB signaling. Expression screening of a cDNA library with a fusion protein containing the SH3 domain yielded a cDNA coding for Apg-2, a member of the heat-shock protein 110 (Hsp 110) subfamily of Hsp70 heat-shock proteins, which is overexpressed in carcinomas. Regulated depletion of Apg-2 in Madin-Darby canine kidney cells inhibits G1/S phase progression. Apg-2 coimmunoprecipitates with ZO-1 and partially localizes to intercellular junctions. Junctional recruitment and coimmunoprecipitation with ZO-1 are stimulated by heat shock. Apg-2 competes with ZONAB for binding to the SH3 domain in vitro and regulates ZONAB's transcriptional activity in reporter gene assays. Our data hence support a model in which Apg-2 regulates ZONAB function by competing for binding to the SH3 domain of ZO-1 and suggest that Apg-2 functions as a regulator of ZO-1–ZONAB signaling in epithelial cells in response to cellular stress.


2003 ◽  
Vol 303 (2) ◽  
pp. 700-706 ◽  
Author(s):  
Fabrice Soncin ◽  
Xinfeng Zhang ◽  
Boyang Chu ◽  
Xiaozhe Wang ◽  
Alexzander Asea ◽  
...  

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