scholarly journals TIP49b, a Regulator of Activating Transcription Factor 2 Response to Stress and DNA Damage

2001 ◽  
Vol 21 (24) ◽  
pp. 8398-8413 ◽  
Author(s):  
Ssang-Goo Cho ◽  
Anindita Bhoumik ◽  
Limor Broday ◽  
Vladimir Ivanov ◽  
Barry Rosenstein ◽  
...  
Keyword(s):  
Dna Damage ◽  
Transcription Factor ◽  
Transcriptional Control ◽  
Constitutive Expression ◽  
Normal Growth ◽  
Growth Conditions ◽  
Interacting Protein ◽  
Response To Stress ◽  
Activating Transcription Factor

ABSTRACT Activating transcription factor 2 (ATF2/CRE-BP1) is implicated in transcriptional control of stress-responsive genes. A yeast two-hybrid screen identified TBP-interacting protein 49b (TIP49b), a component of the INO80 chromatin-remodeling complex, as a novel ATF2-interacting protein. TIP49b's association with ATF2 is phosphorylation dependent and requires amino acids 150 to 248 of ATF2 (ATF2150–248), which are implicated in intramolecular inhibition of ATF2 transcriptional activities. Forced expression of TIP49b efficiently attenuated ATF2 transcriptional activities under normal growth conditions as well as after UV treatment, ionizing irradiation, or activation of p38 kinase, all of which induced ATF2 phosphorylation and increased TIP49b-ATF2 association. Constitutive expression of ATF2150–248 peptide outcompeted TIP49b interaction with ATF2 and alleviated the suppression of ATF2 transcriptional activities. Expression of ATF2150–248 in fibroblasts or melanoma but not in ATF2-null cells caused a profound G2M arrest and increased degree of apoptosis following irradiation. The interaction between ATF2 and TIP49b constitutes a novel mechanism that serves to limit ATF2 transcriptional activities and highlights the central role of ATF2 in the control of the cell cycle and apoptosis in response to stress and DNA damage.

scholarly journals Filamentation in Candida albicans is modulated by adaptive translation of farnesol signalling genes

2021 ◽  
Author(s):  
Carla Oliveira ◽  
Ana Rita Guimarães ◽  
Inês Correia ◽  
Inês Sousa ◽  
Ana Poim ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Molecular Mechanisms ◽  
Phenotypic Diversity ◽  
Critical Role ◽  
Normal Growth ◽  
Morphological Diversity ◽  
Growth Conditions ◽  
Response To Stress ◽  
Variable Morphology

AbstractThe complex biology of the human pathogen Candida albicans is reflected in its remarkable ability to proliferate in numerous body sites, adapt to drastic changes in the environment, form various types of colonies and grow in yeast, pseudo-hyphal and hyphal forms. Much has been learnt in recent years about the relevance of this phenotypic plasticity, but the mechanisms that support it are still not fully understood. We have demonstrated that atypical translation of the CUG codon is a source of unexpected morphological diversity. The CUG codon is translated as both leucine (Leu) (~3%) and serine (Ser) (~97%) in normal growth conditions, but Ser/Leu levels change in response to stress. Remarkably, recombinant C. albicans strains incorporating between 20% and 99% of Leu at CUG sites display a diverse array of phenotypes and produce colonies of variable morphology containing a mixture of yeast, pseudohyphal and hyphal cells. In this work we investigate the role of the CUG codon in the yeast-hypha transition. Our data show that increasing incorporation levels of Leu at CUG sites trigger hyphal initiation under non-inducing conditions by reducing farnesol production, and increasing the degradation of the Nrg1 hyphal repressor. We propose that dual CUG Ser/Leu translation triggers filamentation via the Nrg1 pathway.ImportanceThe unique translation of the CUG codon as both Ser (~97%) and Leu (~3%) plays a key role in the production of high genomic and phenotypic diversity in C. albicans. The molecular mechanisms that support such diversity are poorly understood. Here, we show that increased Leu incorporation at CUG sites induce hyphae formation in media where C. albicans normally grows in the yeast form. The data show that increasing Leu at CUG sites triggers the degradation of the hyphal repressor Nrg1, allowing for full expression of hyphal genes. Since filamentation is important for invasion of host tissues, this work shows how the atypical translation of a single codon may play a critical role in the virulence of all fungi of the CTG clade.

scholarly journals Role of activating transcription factor 3 protein ATF3 in necrosis and apoptosis induced by 5-fluoro-2′-deoxyuridine

FEBS Journal ◽  
2014 ◽  
Vol 281 (7) ◽  
pp. 1892-1900 ◽  
Author(s):  
Akira Sato ◽  
Kentaro Nakama ◽  
Hiroki Watanabe ◽  
Akito Satake ◽  
Akihiro Yamamoto ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Activating Transcription Factor 3 ◽  
Activating Transcription Factor ◽  
Transcription Factor 3

Transcriptional control of human papillomavirus type 18 oncogene expression in different cell lines: Role of transcription factor YY1

Virus Genes ◽  
1995 ◽  
Vol 11 (1) ◽  
pp. 53-58 ◽  
Author(s):  
Franziska Jundt ◽  
Ingrid Herr ◽  
Peter Angel ◽  
Harald Zur Hausen ◽  
Tobias Bauknecht
Keyword(s):  
Transcription Factor ◽  
Human Papillomavirus ◽  
Cell Lines ◽  
Transcriptional Control ◽  
Oncogene Expression ◽  
Transcription Factor Yy1

scholarly journals MtBZR1 Plays an Important Role in Nodule Development in Medicago truncatula

2019 ◽  
Vol 20 (12) ◽  
pp. 2941
Author(s):  
Can Cui ◽  
Hongfeng Wang ◽  
Limei Hong ◽  
Yiteng Xu ◽  
Yang Zhao ◽  
...  
Keyword(s):  
Medicago Truncatula ◽  
Sinorhizobium Meliloti ◽  
Normal Growth ◽  
Dry Mass ◽  
Growth Conditions ◽  
Nodule Development ◽  
Functional Study ◽  
Loss Of Function ◽  
Wild Type

Brassinosteroid (BR) is an essential hormone in plant growth and development. The BR signaling pathway was extensively studied, in which BRASSINAZOLE RESISTANT 1 (BZR1) functions as a key regulator. Here, we carried out a functional study of the homolog of BZR1 in Medicago truncatula R108, whose expression was induced in nodules upon Sinorhizobium meliloti 1021 inoculation. We identified a loss-of-function mutant mtbzr1-1 and generated 35S:MtBZR1 transgenic lines for further analysis at the genetic level. Both the mutant and the overexpression lines of MtBZR1 showed no obvious phenotypic changes under normal growth conditions. After S. meliloti 1021 inoculation, however, the shoot and root dry mass was reduced in mtbzr1-1 compared with the wild type, caused by partially impaired nodule development. The transcriptomic analysis identified 1319 differentially expressed genes in mtbzr1-1 compared with wild type, many of which are involved in nodule development and secondary metabolite biosynthesis. Our results demonstrate the role of MtBZR1 in nodule development in M. truncatula, shedding light on the potential role of BR in legume–rhizobium symbiosis.

scholarly journals Budding Yeast CTDK-I Is Required for DNA Damage-Induced Transcription

2003 ◽  
Vol 2 (2) ◽  
pp. 274-283 ◽  
Author(s):  
Denis Ostapenko ◽  
Mark J. Solomon
Keyword(s):  
Dna Damage ◽  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Large Scale ◽  
Large Subunit ◽  
Growth Conditions ◽  
Dna Damaging Agents ◽  
Irradiation Treatment ◽  
Mutant Cells

ABSTRACT CTDK-I phosphorylates the C-terminal domain (CTD) of the large subunit of yeast RNA polymerase II in a reaction that stimulates transcription elongation. Mutations in CTDK-I subunits—Ctk1p, Ctk2p, and Ctk3p—confer conditional phenotypes. In this study, we examined the role of CTDK-I in the DNA damage response. We found that mutation of individual CTDK-I subunits rendered yeast sensitive to hydroxyurea (HU) and UV irradiation. Treatment with DNA-damaging agents increased phosphorylation of Ser2 within the CTD repeats in wild-type but not in ctk1Δ mutant cells. Using microarray hybridization, we identified genes whose transcription following DNA damage is Ctk1p dependent, including several DNA repair and stress response genes. Following HU treatment, the level of Ser2-phosphorylated RNA polymerase II increased both globally and on the CTDK-I-regulated genes. The pleiotropic phenotypes of ctk mutants suggest that CTDK-I activity is essential during large-scale transcriptional repatterning under stress and unfavorable growth conditions.

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