Faculty Opinions recommendation of Interplay of two transcription factors for recruitment of the chromatin remodeling complex modulates fungal nitrosative stress response.

2021 ◽  
Author(s):  
David Cánovas
Keyword(s):  
Transcription Factors ◽  
Stress Response ◽  
Chromatin Remodeling ◽  
Nitrosative Stress ◽  
Chromatin Remodeling Complex

scholarly journals SWI/SNF Displaces SAGA-Acetylated Nucleosomes

2006 ◽  
Vol 5 (10) ◽  
pp. 1738-1747 ◽  
Author(s):  
Mark Chandy ◽  
José L. Gutiérrez ◽  
Philippe Prochasson ◽  
Jerry L. Workman
Keyword(s):  
Transcription Factors ◽  
Rna Polymerase ◽  
Histone Acetylation ◽  
Chromatin Remodeling ◽  
Binding Sites ◽  
Saga Complex ◽  
Chromatin Remodeling Complex ◽  
Nucleosome Array ◽  
Transcription Activators

ABSTRACT SWI/SNF is a well-characterized chromatin remodeling complex that remodels chromatin by sliding nucleosomes in cis and/or displacing nucleosomes in trans. The latter mechanism has the potential to remove promoter nucleosomes, allowing access to transcription factors and RNA polymerase. In vivo, histone acetylation often precedes apparent nucleosome loss; therefore, we sought to determine whether nucleosomes containing acetylated histones could be displaced by the SWI/SNF chromatin remodeling complex. We found that SAGA-acetylated histones were lost from an immobilized nucleosome array when treated with the SWI/SNF complex. When the nucleosome array was acetylated by SAGA in the presence of bound transcription activators, it generated a peak of acetylation surrounding the activator binding sites. Subsequent SWI/SNF treatment suppressed this acetylation peak. Immunoblots indicated that SWI/SNF preferentially displaced acetylated histones from the array relative to total histones. Moreover, the Swi2/Snf2 bromodomain, an acetyl-lysine binding domain, played a role in the displacement of acetylated histones. These data indicate that targeted histone acetylation by the SAGA complex predisposes promoter nucleosomes for displacement by the SWI/SNF complex.

scholarly journals Cdx2 Regulates Gene Expression through Recruitment of Brg1-associated Switch-Sucrose Non-fermentable (SWI-SNF) Chromatin Remodeling Activity

2017 ◽  
Vol 292 (8) ◽  
pp. 3389-3399 ◽  
Author(s):  
Thinh T. Nguyen ◽  
Joanne G. A. Savory ◽  
Travis Brooke-Bisschop ◽  
Randy Ringuette ◽  
Tanya Foley ◽  
...  
Keyword(s):  
Gene Expression ◽  
Transcriptional Regulation ◽  
Transcription Factors ◽  
Chromatin Remodeling ◽  
Genomic Dna ◽  
Direct Contact ◽  
Target Gene ◽  
Target Genes ◽  
Limited Ability ◽  
Chromatin Remodeling Complex

The packaging of genomic DNA into nucleosomes creates a barrier to transcription that can be relieved through ATP-dependent chromatin remodeling via complexes such as the switch-sucrose non-fermentable (SWI-SNF) chromatin remodeling complex. The SWI-SNF complex remodels chromatin via conformational or positional changes of nucleosomes, thereby altering the access of transcriptional machinery to target genes. The SWI-SNF complex has limited ability to bind to sequence-specific elements, and, therefore, its recruitment to target loci is believed to require interaction with DNA-associated transcription factors. The Cdx family of homeodomain transcript ion factors (Cdx1, Cdx2, and Cdx4) are essential for a number of developmental programs in the mouse. Cdx1 and Cdx2 also regulate intestinal homeostasis throughout life. Although a number of Cdx target genes have been identified, the basis by which Cdx members impact their transcription is poorly understood. We have found that Cdx members interact with the SWI-SNF complex and make direct contact with Brg1, a catalytic member of SWI-SNF. Both Cdx2 and Brg1 co-occupy a number of Cdx target genes, and both factors are necessary for transcriptional regulation of such targets. Finally, Cdx2 and Brg1 occupancy occurs coincident with chromatin remodeling at some of these loci. Taken together, our findings suggest that Cdx transcription factors regulate target gene expression, in part, through recruitment of Brg1-associated SWI-SNF chromatin remodeling activity.

scholarly journals Actin-Related Protein 4 Interacts with PIE1 and Regulates Gene Expression in Arabidopsis

Genes ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 520
Author(s):  
Wenfeng Nie ◽  
Jinyu Wang
Keyword(s):  
Gene Expression ◽  
Plant Growth ◽  
Chromatin Remodeling ◽  
Leaf Size ◽  
Early Flowering ◽  
Physical Interaction ◽  
Loss Of Function ◽  
Single Nucleotide Change ◽  
Chromatin Remodeling Complex ◽  
Related Proteins

As essential structural components of ATP-dependent chromatin-remodeling complex, the nucleolus-localized actin-related proteins (ARPs) play critical roles in many biological processes. Among them, ARP4 is identified as an integral subunit of chromatin remodeling complex SWR1, which is conserved in yeast, humans and plants. It was shown that RNAi mediated knock-down of Arabidopsis thaliana ARP4 (AtARP4) could affect plant development, specifically, leading to early flowering. However, so far, little is known about how ARP4 functions in the SWR1 complex in plant. Here, we identified a loss-of-function mutant of AtARP4 with a single nucleotide change from glycine to arginine, which had significantly smaller leaf size. The results from the split luciferase complementation imaging (LCI) and yeast two hybrid (Y2H) assays confirmed its physical interaction with the scaffold and catalytic subunit of SWR1 complex, photoperiod-independent early flowering 1 (PIE1). Furthermore, mutation of AtARP4 caused altered transcription response of hundreds of genes, in which the number of up-regulated differentially expressed genes (DEGs) was much larger than those down-regulated. Although most DEGs in atarp4 are related to plant defense and response to hormones such as salicylic acid, overall, it has less overlapping with other swr1 mutants and the hta9 hta11 double-mutant. In conclusion, our results reveal that AtARP4 is important for plant growth and such an effect is likely attributed to its repression on gene expression, typically at defense-related loci, thus providing some evidence for the coordination of plant growth and defense, while the regulatory patterns and mechanisms are distinctive from other SWR1 complex components.

scholarly journals The impact of bZIP Atf1ortholog global regulators in fungi

2021 ◽  
Author(s):  
Éva Leiter ◽  
Tamás Emri ◽  
Klaudia Pákozdi ◽  
László Hornok ◽  
István Pócsi
Keyword(s):  
Transcription Factors ◽  
Stress Response ◽  
Secondary Metabolite ◽  
Plant Pathogens ◽  
Leucine Zipper ◽  
Secondary Metabolite Production ◽  
Special Focus ◽  
Human Pathogens ◽  
Metabolite Production ◽  
The Impact

Abstract Regulation of signal transduction pathways is crucial for the maintenance of cellular homeostasis and organismal development in fungi. Transcription factors are key elements of this regulatory network. The basic-region leucine zipper (bZIP) domain of the bZIP-type transcription factors is responsible for DNA binding while their leucine zipper structural motifs are suitable for dimerization with each other facilitiating the formation of homodimeric or heterodimeric bZIP proteins. This review highlights recent knowledge on the function of fungal orthologs of the Schizosaccharomyces pombe Atf1, Aspergillus nidulans AtfA, and Fusarium verticillioides FvAtfA, bZIP-type transcription factors with a special focus on pathogenic species. We demonstrate that fungal Atf1-AtfA-FvAtfA orthologs play an important role in vegetative growth, sexual and asexual development, stress response, secondary metabolite production, and virulence both in human pathogens, including Aspergillus fumigatus, Mucor circinelloides, Penicillium marneffei, and Cryptococcus neoformans and plant pathogens, like Fusarium ssp., Magnaporthe oryzae, Claviceps purpurea, Botrytis cinerea, and Verticillium dahliae. Key points • Atf1 orthologs play crucial role in the growth and development of fungi. • Atf1 orthologs orchestrate environmental stress response of fungi. • Secondary metabolite production and virulence are coordinated by Atf1 orthologs.

scholarly journals Interplay of BAF and MLL4 promotes cell type-specific enhancer activation

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Young-Kwon Park ◽  
Ji-Eun Lee ◽  
Zhijiang Yan ◽  
Kaitlin McKernan ◽  
Tommy O’Haren ◽  
...  
Keyword(s):  
Cell Differentiation ◽  
Chromatin Remodeling ◽  
Direct Evidence ◽  
Cell Type ◽  
Chromatin Regulators ◽  
Chromatin Remodeling Complex ◽  
Histone H3k4 ◽  
Cell Type Specific ◽  
Pioneer Transcription Factor ◽  
Factor C

AbstractCell type-specific enhancers are activated by coordinated actions of lineage-determining transcription factors (LDTFs) and chromatin regulators. The SWI/SNF chromatin remodeling complex BAF and the histone H3K4 methyltransferase MLL4 (KMT2D) are both implicated in enhancer activation. However, the interplay between BAF and MLL4 in enhancer activation remains unclear. Using adipogenesis as a model system, we identify BAF as the major SWI/SNF complex that colocalizes with MLL4 and LDTFs on active enhancers and is required for cell differentiation. In contrast, the promoter enriched SWI/SNF complex PBAF is dispensable for adipogenesis. By depleting BAF subunits SMARCA4 (BRG1) and SMARCB1 (SNF5) as well as MLL4 in cells, we show that BAF and MLL4 reciprocally regulate each other’s binding on active enhancers before and during adipogenesis. By focusing on enhancer activation by the adipogenic pioneer transcription factor C/EBPβ without inducing cell differentiation, we provide direct evidence for an interdependent relationship between BAF and MLL4 in activating cell type-specific enhancers. Together, these findings reveal a positive feedback between BAF and MLL4 in promoting LDTF-dependent activation of cell type-specific enhancers.

Clade III cytokinin response factors share common roles in response to oxidative stress responses linked to cytokinin synthesis

2021 ◽  
Vol 72 (8) ◽  
pp. 3294-3306
Author(s):  
Ariel M Hughes ◽  
H Tucker Hallmark ◽  
Lenka Plačková ◽  
Ondrej Novák ◽  
Aaron M Rashotte
Keyword(s):  
Oxidative Stress ◽  
Transcription Factors ◽  
Stress Response ◽  
Stress Responses ◽  
Oxidative Stress Response ◽  
Response Factors ◽  
Ontology Term ◽  
Regulated Expression ◽  
Cytokinin Response ◽  
Oxidative Stress Responses

Abstract Cytokinin response factors (CRFs) are transcription factors that are involved in cytokinin (CK) response, as well as being linked to abiotic stress tolerance. In particular, oxidative stress responses are activated by Clade III CRF members, such as AtCRF6. Here we explored the relationships between Clade III CRFs and oxidative stress. Transcriptomic responses to oxidative stress were determined in two Clade III transcription factors, Arabidopsis AtCRF5 and tomato SlCRF5. AtCRF5 was required for regulated expression of >240 genes that are involved in oxidative stress response. Similarly, SlCRF5 was involved in the regulated expression of nearly 420 oxidative stress response genes. Similarities in gene regulation by these Clade III members in response to oxidative stress were observed between Arabidopsis and tomato, as indicated by Gene Ontology term enrichment. CK levels were also changed in response to oxidative stress in both species. These changes were regulated by Clade III CRFs. Taken together, these findings suggest that Clade III CRFs play a role in oxidative stress response as well as having roles in CK signaling.

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