EcbZIP60, a basic leucine zipper transcription factor from Eleusine coracana L. improves abiotic stress tolerance in tobacco by activating unfolded protein response pathway

2015 ◽  
Vol 35 (9) ◽  
Author(s):  
K. C. Babitha ◽  
S. V. Ramu ◽  
Karaba N. Nataraja ◽  
M. S. Sheshshayee ◽  
M. Udayakumar
Keyword(s):  
Transcription Factor ◽  
Abiotic Stress ◽  
Unfolded Protein Response ◽  
Stress Tolerance ◽  
Leucine Zipper ◽  
Abiotic Stress Tolerance ◽  
Eleusine Coracana ◽  
Basic Leucine Zipper ◽  
Unfolded Protein ◽  
Protein Response

scholarly journals SCFCdc4-mediated Degradation of the Hac1p Transcription Factor Regulates the Unfolded Protein Response inSaccharomyces cerevisiae

2007 ◽  
Vol 18 (2) ◽  
pp. 426-440 ◽  
Author(s):  
Bhupinder Pal ◽  
Nickie C. Chan ◽  
Leon Helfenbaum ◽  
Kaeling Tan ◽  
William P. Tansey ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Unfolded Protein Response ◽  
Rna Polymerase Ii ◽  
Nuclear Localization ◽  
Leucine Zipper ◽  
Nuclear Localization Sequence ◽  
Basic Leucine Zipper ◽  
Unfolded Protein ◽  
Yeast Genes ◽  
Protein Response

The Saccharomyces cerevisiae basic leucine zipper transcription factor Hac1p is synthesized in response to the accumulation of unfolded polypeptides in the lumen of the endoplasmic reticulum (ER), and it is responsible for up-regulation of ∼5% of all yeast genes, including ER-resident chaperones and protein-folding catalysts. Hac1p is one of the most short-lived yeast proteins, having a half-life of ∼1.5 min. Here, we have shown that Hac1p harbors a functional PEST degron and that degradation of Hac1p by the proteasome involves the E2 ubiquitin-conjugating enzyme Ubc3/Cdc34p and the SCFCdc4E3 complex. Consistent with the known nuclear localization of Cdc4p, rapid degradation of Hac1p requires the presence of a functional nuclear localization sequence, which we demonstrated to involve basic residues in the sequence29RKRAKTK35. Two-hybrid analysis demonstrated that the PEST-dependent interaction of Hac1p with Cdc4p requires Ser146 and Ser149. Turnover of Hac1p may be dependent on transcription because it is inhibited in cell mutants lacking Srb10 kinase, a component of the SRB/mediator module of the RNA polymerase II holoenzyme. Stabilization of Hac1p by point mutation or deletion, or as the consequence of defects in components of the degradation pathway, results in increased unfolded protein response element-dependent transcription and improved cell viability under ER stress conditions.

Heterologous Overexpression of ZmHDZIV13 Enhanced Drought and Salt Tolerance in Arabidopsis and Tobacco

2021 ◽  
Author(s):  
Fang Wang ◽  
Peng Fang ◽  
Huiping Yan ◽  
Xiangzhuo Ji ◽  
Yunling Peng
Keyword(s):  
Transcription Factor ◽  
Abiotic Stress ◽  
Salt Tolerance ◽  
Leucine Zipper ◽  
Abiotic Stress Tolerance ◽  
Heterologous Overexpression ◽  
Malondialdehyde Content ◽  
Drought And Salt Tolerance ◽  
Relative Water ◽  
Dependent Signaling Pathway

Abstract The homeodomain leucine zipper (HD-Zip) IV transcription factor is indispensable in the response of plants to abiotic stress. Systematic studies have been carried out in Arabidopsis, rice and other species from which a series of stress resistance-related genes have been isolated. However, the function of the HD-Zip-IV protein in maize is not clear. In this study, we cloned the HD-Zip-IV gene ZmHDZIV13 and identified its function in the stress response. Our phylogenetic analysis showed that ZmHDZIV13 and AtHDG11 had high homology and might have similar functions. The heterologous overexpression of ZmHDZIV13 in Arabidopsis resulted in sensitivity to abscisic acid (ABA), salt tolerance during germination and drought tolerance in seedlings. Under drought stress, the transgenic Arabidopsis showed stronger drought resistance than the wild-type showed (control). The malondialdehyde content of ZmHDZIV13 transgenic plants was lower than that of the control, and the relative water content and proline content were significantly higher than those of the control. After the drought was relieved, the expression of P5CS1, RD22, RD29B, RD29A, NCED3 and ERD1 were upregulated in transgenic Arabidopsis. Also, modified tobacco plants (35S::ZmHDZIV13) exhibited proper stomatal changes in response to drought conditions. These results show that ZmHDZIV13, as a stress-responsive transcription factor, plays a role in the positive regulation of abiotic stress tolerance and can regulate an ABA-dependent signaling pathway to regulate drought response in plants.

scholarly journals Inhibition of IRE1α-mediated XBP1 mRNA cleavage by XBP1 reveals a novel regulatory process during the unfolded protein response

2017 ◽  
Vol 2 ◽  
pp. 36 ◽  
Author(s):  
Fiona Chalmers ◽  
Bernadette Sweeney ◽  
Katharine Cain ◽  
Neil J. Bulleid
Keyword(s):  
Transcription Factor ◽  
Unfolded Protein Response ◽  
Target Genes ◽  
Feedback Mechanism ◽  
Ribonuclease Activity ◽  
Stable Cell Line ◽  
Factor X ◽  
Unfolded Protein ◽  
Xbp1 Mrna ◽  
Protein Response

Background: The mammalian endoplasmic reticulum (ER) continuously adapts to the cellular secretory load by the activation of an unfolded protein response (UPR).  This stress response results in expansion of the ER, upregulation of proteins involved in protein folding and degradation, and attenuation of protein synthesis.  The response is orchestrated by three signalling pathways each activated by a specific signal transducer, either inositol requiring enzyme α (IRE1α), double-stranded RNA-activated protein kinase-like ER kinase (PERK) or activating transcription factor 6 (ATF6).  Activation of IRE1α results in its oligomerisation, autophosphorylation and stimulation of its ribonuclease activity.  The ribonuclease initiates the splicing of an intron from mRNA encoding the transcription factor, X-box binding protein 1 (XBP1), as well as degradation of specific mRNAs and microRNAs. Methods: To investigate the consequence of expression of exogenous XBP1, we generated a stable cell-line expressing spliced XBP1 mRNA under the control of an inducible promotor.  Results: Following induction of expression, high levels of XBP1 protein were detected, which allowed upregulation of target genes in the absence of induction of the UPR.  Remarkably under stress conditions, the expression of exogenous XBP1 repressed splicing of endogenous XBP1 mRNA without repressing the activation of PERK.  Conclusions: These results illustrate that a feedback mechanism exists to attenuate activation of the Ire1α ribonuclease activity in the presence of XBP1.

Overexpression of VaPAT1, a GRAS transcription factor from Vitis amurensis, confers abiotic stress tolerance in Arabidopsis

2015 ◽  
Vol 35 (3) ◽  
pp. 655-666 ◽  
Author(s):  
Yangyang Yuan ◽  
Linchuan Fang ◽  
Sospeter Karanja Karungo ◽  
Langlang Zhang ◽  
Yingying Gao ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Abiotic Stress ◽  
Stress Tolerance ◽  
Abiotic Stress Tolerance ◽  
Vitis Amurensis ◽  
Gras Transcription Factor

scholarly journals The Saccharomycescerevisiae Isw2p-Itc1p Complex RepressesINO1 Expression and Maintains Cell Morphology

2001 ◽  
Vol 183 (17) ◽  
pp. 4985-4993 ◽  
Author(s):  
Minetaka Sugiyama ◽  
Jun-Ichi Nikawa
Keyword(s):  
Leucine Zipper ◽  
Suppressor Gene ◽  
Dominant Negative ◽  
Gene Products ◽  
Truncated Form ◽  
Basic Leucine Zipper ◽  
Multicopy Suppressor ◽  
Unfolded Protein ◽  
The Unfolded Protein Response ◽  
Protein Response

ABSTRACT In the yeast Saccharomyces cerevisiae, IRE1 encodes a bifunctional protein with transmembrane kinase and endoribonuclease activities. HAC1 encodes a transcription factor which has a basic leucine zipper domain. Both gene products play a crucial role in the unfolded protein response. Mutants in which one of these genes is defective also show the inositol-auxotrophic (Ino−) phenotype, but the reason for this has not been clear. To investigate the mechanism underlying the Ino−phenotype, we screened a multicopy suppressor gene which can suppress the Ino− phenotype of the Δhac1 strain. We obtained a truncated form of the ITC1 gene that has a defect in its 3′ region. Although the truncated form ofITC1 clearly suppressed the Ino− phenotype of the Δhac1 strain, the full-lengthITC1 had a moderate effect. The gene products ofITC1 and ISW2 are known to constitute a chromatin-remodeling complex (T. Tsukiyama, J. Palmer, C. C. Landel, J. Shiloach, and C. Wu, Genes Dev. 13:686–697, 1999). Surprisingly, the deletion of either ITC1 orISW2 in the Δhac1 strain circumvented the inositol requirement and caused derepression of INO1even under repression conditions, i.e., in inositol-containing medium. These data indicate that the Isw2p-Itc1p complex usually repressesINO1 expression and that overexpression of the truncated form of ITC1 functions in a dominant negative manner inINO1 repression. It is conceivable that the repressor function of this complex is regulated by the C-terminal region of Itc1p.

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