A Transcription Factor Regulates Gene Expression in Chloroplasts

The chloroplast is a semi-autonomous organelle with its own genome. The expression of chloroplast genes depends on both chloroplasts and the nucleus. Although many nucleus-encoded proteins have been shown to localize in chloroplasts and are essential for chloroplast gene expression, it is not clear whether transcription factors can regulate gene expression in chloroplasts. Here we report that the transcription factor NAC102 localizes in both chloroplasts and nucleus in Arabidopsis. Specifically, NAC102 localizes in chloroplast nucleoids. Yeast two-hybrid assay and co-immunoprecipitation assay suggested that NAC102 interacts with chloroplast RNA polymerases. Furthermore, overexpression of NAC102 in chloroplasts leads to reduced chloroplast gene expression and chlorophyll content, indicating that NAC102 functions as a repressor in chloroplasts. Our study not only revealed that transcription factors are new regulators of chloroplast gene expression, but also discovered that transcription factors can function in chloroplasts in addition to the canonical organelle nucleus.

Download Full-text

Gene Expression and Yeast Two-Hybrid Studies of 1R-MYB Transcription Factor Mediating Drought Stress Response in Chickpea (Cicer arietinum L.)

Frontiers in Plant Science ◽

10.3389/fpls.2015.01117 ◽

2015 ◽

Vol 6 ◽

Cited By ~ 10

Author(s):

Abirami Ramalingam ◽

Himabindu Kudapa ◽

Lekha T. Pazhamala ◽

Vanika Garg ◽

Rajeev K. Varshney

Keyword(s):

Gene Expression ◽

Transcription Factor ◽

Drought Stress ◽

Stress Response ◽

Cicer Arietinum ◽

Myb Transcription Factor ◽

Yeast Two Hybrid ◽

Cicer Arietinum L ◽

Two Hybrid

Download Full-text

Challenges of Decoding Transcription Factor Dynamics in Terms of Gene Regulation

Cells ◽

10.3390/cells7090132 ◽

2018 ◽

Vol 7 (9) ◽

pp. 132 ◽

Cited By ~ 1

Author(s):

Erik Martin ◽

Myong-Hee Sung

Keyword(s):

Gene Expression ◽

Transcription Factor ◽

Transcription Factors ◽

Cell Biology ◽

Extrinsic Factors ◽

Regulate Gene Expression ◽

Technological Advances ◽

Experimental Approaches ◽

Intrinsic And Extrinsic Factors ◽

Regulate Gene

Technological advances are continually improving our ability to obtain more accurate views about the inner workings of biological systems. One such rapidly evolving area is single cell biology, and in particular gene expression and its regulation by transcription factors in response to intrinsic and extrinsic factors. Regarding the study of transcription factors, we discuss some of the promises and pitfalls associated with investigating how individual cells regulate gene expression through modulation of transcription factor activities. Specifically, we discuss four leading experimental approaches, the data that can be obtained from each, and important considerations that investigators should be aware of when drawing conclusions from such data.

Download Full-text

Transcription Factor ANAC074 Binds to NRS1, NRS2, or MybSt1 Element in Addition to the NACRS to Regulate Gene Expression

International Journal of Molecular Sciences ◽

10.3390/ijms19103271 ◽

2018 ◽

Vol 19 (10) ◽

pp. 3271

Author(s):

Lin He ◽

Jingyu Xu ◽

Yucheng Wang ◽

Kejun Yang

Keyword(s):

Gene Expression ◽

Arabidopsis Thaliana ◽

Transcription Factor ◽

Transcription Factors ◽

Biological Processes ◽

Regulate Gene Expression ◽

Cis Element ◽

Stress Responsive Genes ◽

Regulate Gene ◽

Gus Assays

NAC (NAM, ATAF1/2, and CUC2) transcription factors play important roles in many biological processes, and mainly bind to the NACRS with core sequences “CACG” or “CATGTG” to regulate gene expression. However, whether NAC proteins can bind to other motifs without these core sequences remains unknown. In this study, we employed a Transcription Factor-Centered Yeast one Hybrid (TF-Centered Y1H) screen to study the motifs recognized by ANAC074. In addition to the NACRS core cis-element, we identified that ANAC074 could bind to MybSt1, NRS1, and NRS2. Y1H and GUS assays showed that ANAC074 could bind the promoters of ethylene responsive genes and stress responsive genes via the NRS1, NRS2, or MybSt1 element. ChIP study further confirmed that the bindings of ANAC074 to MybSt1, NRS1, and NRS2 actually occurred in Arabidopsis. Furthermore, ten NAC proteins from different NAC subfamilies in Arabidopsis thaliana were selected and confirmed to bind to the MybSt1, NRS1, and NRS2 motifs, indicating that they are recognized commonly by NACs. These findings will help us to further reveal the functions of NAC proteins.

Download Full-text

Arabidopsis heat shock transcription factor HSFA7b positively mediates salt stress tolerance by binding to an E-box-like motif to regulate gene expression

Journal of Experimental Botany ◽

10.1093/jxb/erz261 ◽

2019 ◽

Vol 70 (19) ◽

pp. 5355-5374 ◽

Cited By ~ 11

Author(s):

Dandan Zang ◽

Jingxin Wang ◽

Xin Zhang ◽

Zhujun Liu ◽

Yucheng Wang

Keyword(s):

Gene Expression ◽

Transcription Factors ◽

Heat Shock ◽

Salt Tolerance ◽

Stress Responses ◽

Ion Homeostasis ◽

Cellulose Synthase ◽

Regulate Gene Expression ◽

E Box ◽

Regulate Gene

Abstract Plant heat shock transcription factors (HSFs) are involved in heat and other abiotic stress responses. However, their functions in salt tolerance are little known. In this study, we characterized the function of a HSF from Arabidopsis, AtHSFA7b, in salt tolerance. AtHSFA7b is a nuclear protein with transactivation activity. ChIP-seq combined with an RNA-seq assay indicated that AtHSFA7b preferentially binds to a novel cis-acting element, termed the E-box-like motif, to regulate gene expression; it also binds to the heat shock element motif. Under salt conditions, AtHSFA7b regulates its target genes to mediate serial physiological changes, including maintaining cellular ion homeostasis, reducing water loss rate, decreasing reactive oxygen species accumulation, and adjusting osmotic potential, which ultimately leads to improved salt tolerance. Additionally, most cellulose synthase-like (CSL) and cellulose synthase (CESA) family genes were inhibited by AtHSFA7b; some of them were randomly selected for salt tolerance characterization, and they were mainly found to negatively modulate salt tolerance. By contrast, some transcription factors (TFs) were induced by AtHSFA7b; among them, we randomly identified six TFs that positively regulate salt tolerance. Thus, AtHSFA7b serves as a transactivator that positively mediates salinity tolerance mainly through binding to the E-box-like motif to regulate gene expression.

Download Full-text

Subnuclear compartmentalization of sequence-specific transcription factors and regulation of eukaryotic gene expression

Biochemistry and Cell Biology ◽

10.1139/o05-062 ◽

2005 ◽

Vol 83 (4) ◽

pp. 535-547 ◽

Cited By ~ 7

Author(s):

Gareth N Corry ◽

D Alan Underhill

Keyword(s):

Gene Expression ◽

Transcription Factor ◽

Transcription Factors ◽

Transcriptional Activation ◽

Current Knowledge ◽

Nuclear Architecture ◽

Subnuclear Localization ◽

Modular Structures

To date, the majority of the research regarding eukaryotic transcription factors has focused on characterizing their function primarily through in vitro methods. These studies have revealed that transcription factors are essentially modular structures, containing separate regions that participate in such activities as DNA binding, protein–protein interaction, and transcriptional activation or repression. To fully comprehend the behavior of a given transcription factor, however, these domains must be analyzed in the context of the entire protein, and in certain cases the context of a multiprotein complex. Furthermore, it must be appreciated that transcription factors function in the nucleus, where they must contend with a variety of factors, including the nuclear architecture, chromatin domains, chromosome territories, and cell-cycle-associated processes. Recent examinations of transcription factors in the nucleus have clarified the behavior of these proteins in vivo and have increased our understanding of how gene expression is regulated in eukaryotes. Here, we review the current knowledge regarding sequence-specific transcription factor compartmentalization within the nucleus and discuss its impact on the regulation of such processes as activation or repression of gene expression and interaction with coregulatory factors.Key words: transcription, subnuclear localization, chromatin, gene expression, nuclear architecture.

Download Full-text

The AML-associated K313 mutation enhances C/EBPα activity by leading to C/EBPα overexpression

Cell Death and Disease ◽

10.1038/s41419-021-03948-6 ◽

2021 ◽

Vol 12 (7) ◽

Author(s):

Ian Edward Gentle ◽

Isabel Moelter ◽

Mohamed Tarek Badr ◽

Konstanze Döhner ◽

Michael Lübbert ◽

...

Keyword(s):

Gene Expression ◽

Cell Culture ◽

Transcription Factor ◽

Transcription Factors ◽

Transcriptional Activity ◽

Target Gene ◽

Wild Type ◽

Elevated Expression ◽

Factor C ◽

Acute Myeloid

AbstractMutations in the transcription factor C/EBPα are found in ~10% of all acute myeloid leukaemia (AML) cases but the contribution of these mutations to leukemogenesis is incompletely understood. We here use a mouse model of granulocyte progenitors expressing conditionally active HoxB8 to assess the cell biological and molecular activity of C/EBPα-mutations associated with human AML. Both N-terminal truncation and C-terminal AML-associated mutations of C/EBPα substantially altered differentiation of progenitors into mature neutrophils in cell culture. Closer analysis of the C/EBPα-K313-duplication showed expansion and prolonged survival of mutant C/EBPα-expressing granulocytes following adoptive transfer into mice. C/EBPα-protein containing the K313-mutation further showed strongly enhanced transcriptional activity compared with the wild-type protein at certain promoters. Analysis of differentially regulated genes in cells overexpressing C/EBPα-K313 indicates a strong correlation with genes regulated by C/EBPα. Analysis of transcription factor enrichment in the differentially regulated genes indicated a strong reliance of SPI1/PU.1, suggesting that despite reduced DNA binding, C/EBPα-K313 is active in regulating target gene expression and acts largely through a network of other transcription factors. Strikingly, the K313 mutation caused strongly elevated expression of C/EBPα-protein, which could also be seen in primary K313 mutated AML blasts, explaining the enhanced C/EBPα activity in K313-expressing cells.

Download Full-text