Compensatory responses of protein import and transcription factor expression in mitochondrial DNA defects

2004 ◽  
Vol 286 (4) ◽  
pp. C867-C875 ◽  
Author(s):  
Anna-Maria Joseph ◽  
Arne A. Rungi ◽  
Brian H. Robinson ◽  
David A. Hood
Keyword(s):  
Transcription Factor ◽  
Mitochondrial Dna ◽  
Transcription Factors ◽  
Mitochondrial Biogenesis ◽  
Protein Import ◽  
Fluorescent Protein ◽  
Expression Patterns ◽  
Yellow Fluorescent Protein ◽  
Nuclear Gene ◽  
Protein Levels

Defects in mitochondrial DNA (mtDNA) evoke distinctive responses in the nuclear genome, leading to altered mitochondrial biogenesis. We used C2C12 cells depleted of mtDNA (rho– cells) and fibroblasts from a mitochondrial encephalopathy, lactic acidosis, and strokelike episodes (MELAS) patient to examine adaptations of the protein import machinery and transcription factors involved in mitochondrial biogenesis. In rho– cells, Tom20 and Tim23 protein levels were reduced by 25% and 59%, whereas mtHSP70 was induced by twofold relative to control cells. These changes were accompanied by a 21% increase in enhanced yellow fluorescent protein (EYFP) import into mitochondria in rho– cells ( P < 0.05). In contrast, in MELAS cells mtHSP70 was elevated by 70%, whereas Tom20 and Tom34 protein levels were increased by 45% and 112% relative to control values. EYFP import was not altered in MELAS cells. In rho– cells, protein levels of the transcription factors nuclear respiratory factor-1 (NRF-1) and transcription factor A (Tfam) declined by 33% and 54%, whereas no change was observed for the coactivator peroxisome proliferator receptor-γ coactivator-1α (PGC-1α). In contrast, Tfam was increased by 40% in MELAS cells. Rho– cells displayed reduced oxygen consumption (V̇o2) and ATP levels, along with a twofold increase in lactate levels ( P < 0.05). In electrically stimulated C2C12 cells, 109%, 78%, 60%, and 67% increases were observed in mtDNA, V̇o2, cytochrome- c oxidase (COX) activity, and Tom34 levels, respectively ( P < 0.05). Our findings suggest that compensatory adaptations occurred to maintain normal rates of protein import in response to mtDNA defects and support a role for contractile activity in reducing pathophysiology associated with mtDNA depletion. Because the expression of nuclear-encoded transcription factors and protein import machinery components was dependent on the type of mtDNA defect, these findings suggest involvement of distinct signaling cascades, each dependent on the type of mitochondrial defect, resulting in divergent changes in nuclear gene expression patterns.

scholarly journals Diethylstilbestrol, a Novel ANO1 Inhibitor, Exerts an Anticancer Effect on Non-Small Cell Lung Cancer via Inhibition of ANO1

2021 ◽  
Vol 22 (13) ◽  
pp. 7100
Author(s):  
Yohan Seo ◽  
Sung Baek Jeong ◽  
Joo Han Woo ◽  
Oh-Bin Kwon ◽  
Sion Lee ◽  
...  
Keyword(s):  
Lung Cancer ◽  
Small Cell Lung Cancer ◽  
Cell Lung Cancer ◽  
High Throughput Screening ◽  
Fluorescent Protein ◽  
Yellow Fluorescent Protein ◽  
Small Cell ◽  
Channel Activity ◽  
Small Cell Lung ◽  
Protein Levels

Non-small cell lung cancer (NSCLC) is one of the leading causes of cancer-related mortality; thus, therapeutic targets continue to be developed. Anoctamin1 (ANO1), a novel drug target considered for the treatment of NSCLC, is a Ca2+-activated chloride channel (CaCC) overexpressed in various carcinomas. It plays an important role in the development of cancer; however, the role of ANO1 in NSCLC is unclear. In this study, diethylstilbestrol (DES) was identified as a selective ANO1 inhibitor using high-throughput screening. We found that DES inhibited yellow fluorescent protein (YFP) fluorescence reduction caused by ANO1 activation but did not inhibit cystic fibrosis transmembrane conductance regulator channel activity or P2Y activation-related cytosolic Ca2+ levels. Additionally, electrophysiological analyses showed that DES significantly reduced ANO1 channel activity, but it more potently reduced ANO1 protein levels. DES also inhibited the viability and migration of PC9 cells via the reduction in ANO1, phospho-ERK1/2, and phospho-EGFR levels. Moreover, DES induced apoptosis by increasing caspase-3 activity and PARP-1 cleavage in PC9 cells, but it did not affect the viability of hepatocytes. These results suggest that ANO1 is a crucial target in the treatment of NSCLC, and DES may be developed as a potential anti-NSCLC therapeutic agent.

scholarly journals STAT3 Is an Upstream Regulator of Granzyme G in the Maternal-To-Zygotic Transition of Mouse Embryos

2021 ◽  
Vol 22 (1) ◽  
pp. 460
Author(s):  
Huan Ou-Yang ◽  
Shinn-Chih Wu ◽  
Li-Ying Sung ◽  
Shiao-Hsuan Yang ◽  
Shang-Hsun Yang ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Transcription Factors ◽  
Fluorescent Protein ◽  
Mouse Embryos ◽  
Cell Nuclei ◽  
Cell Stage ◽  
Promoter Assay ◽  
Maternal To Zygotic Transition ◽  
Mouse Zygotes ◽  
Time Specific

The maternal-to-zygotic transition (MZT), which controls maternal signaling to synthesize zygotic gene products, promotes the preimplantation development of mouse zygotes to the two-cell stage. Our previous study reported that mouse granzyme g (Gzmg), a serine-type protease, is required for the MZT. In this study, we further identified the maternal factors that regulate the Gzmg promoter activity in the zygote to the two-cell stage of mouse embryos. A full-length Gzmg promoter from mouse genomic DNA, FL-pGzmg (−1696~+28 nt), was cloned, and four deletion constructs of this Gzmg promoter, Δ1-pGzmg (−1369~+28 nt), Δ2-pGzmg (−939~+28 nt), Δ3-pGzmg (−711~+28 nt) and Δ4-pGzmg (−417~+28 nt), were subsequently generated. Different-sized Gzmg promoters were used to perform promoter assays of mouse zygotes and two-cell stage embryos. The results showed that Δ4-pGzmg promoted the highest expression level of the enhanced green fluorescent protein (EGFP) reporter in the zygotes and two-cell embryos. The data suggested that time-specific transcription factors upregulated Gzmg by binding cis-elements in the −417~+28-nt Gzmg promoter region. According to the results of the promoter assay, the transcription factor binding sites were predicted and analyzed with the JASPAR database, and two transcription factors, signal transducer and activator of transcription 3 (STAT3) and GA-binding protein alpha (GABPα), were identified. Furthermore, STAT3 and GABPα are expressed and located in zygote pronuclei and two-cell nuclei were confirmed by immunofluorescence staining; however, only STAT3 was recruited to the mouse zygote pronuclei and two-cell nuclei injected with the Δ4-pGzmg reporter construct. These data indicated that STAT3 is a maternal transcription factor and may upregulate Gzmg to promote the MZT. Furthermore, treatment with a STAT3 inhibitor, S3I-201, caused mouse embryonic arrest at the zygote and two-cell stages. These results suggest that STAT3, a maternal protein, is a critical transcription factor and regulates Gzmg transcription activity in preimplantation mouse embryos. It plays an important role in the maternal-to-zygotic transition during early embryonic development.

A human mitochondrial transcriptional activator can functionally replace a yeast mitochondrial HMG-box protein both in vivo and in vitro

1993 ◽  
Vol 13 (3) ◽  
pp. 1951-1961
Author(s):  
M A Parisi ◽  
B Xu ◽  
D A Clayton
Keyword(s):  
Transcription Factor ◽  
Mitochondrial Dna ◽  
Nuclear Gene ◽  
Transcriptional Activator ◽  
Yeast Mitochondria ◽  
Yeast Protein ◽  
Mitochondrial Transcription ◽  
Mitochondrial Transcription Factor ◽  
Mitochondrial Transcription Factor A

Human mitochondrial transcription factor A is a 25-kDa protein that binds immediately upstream of the two major mitochondrial promoters, thereby leading to correct and efficient initiation of transcription. Although the nature of yeast mitochondrial promoters is significantly different from that of human promoters, a potential functional homolog of the human transcriptional activator protein has been previously identified in yeast mitochondria. The importance of the yeast protein in yeast mitochondrial DNA function has been shown by inactivation of its nuclear gene (ABF2) in Saccharomyces cerevisiae cells resulting in loss of mitochondrial DNA. We report here that the nuclear gene for human mitochondrial transcription factor A can be stably expressed in yeast cells devoid of the yeast homolog protein. The human protein is imported efficiently into yeast mitochondria, is processed correctly, and rescues the loss-of-mitochondrial DNA phenotype in a yeast abf2 strain, thus functionally substituting for the yeast protein. Both human and yeast proteins affect yeast mitochondrial transcription initiation in vitro, suggesting that the two proteins may have a common role in this fundamental process.

scholarly journals Evolutionarily conserved transcription factors drive the oxidative stress response in Drosophila

2020 ◽  
Vol 223 (14) ◽  
pp. jeb221622
Author(s):  
Sarah M. Ryan ◽  
Kaitie Wildman ◽  
Briseida Oceguera-Perez ◽  
Scott Barbee ◽  
Nathan T. Mortimer ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Transcription Factor ◽  
Transcription Factors ◽  
Stress Responses ◽  
Binding Sites ◽  
Regulatory Elements ◽  
Genomic Locus ◽  
Biologically Relevant ◽  
Protein Levels ◽  
Putative Transcription Factor

ABSTRACTAs organisms are constantly exposed to the damaging effects of oxidative stress through both environmental exposure and internal metabolic processes, they have evolved a variety of mechanisms to cope with this stress. One such mechanism is the highly conserved p38 MAPK (p38K) pathway, which is known to be post-translationally activated in response to oxidative stress, resulting in the activation of downstream antioxidant targets. However, little is known about the role of p38K transcriptional regulation in response to oxidative stress. Therefore, we analyzed the p38K gene family across the genus Drosophila to identify conserved regulatory elements. We found that oxidative stress exposure results in increased p38K protein levels in multiple Drosophila species and is associated with increased oxidative stress resistance. We also found that the p38Kb genomic locus includes conserved AP-1 and lola-PT transcription factor consensus binding sites. Accordingly, over-expression of these transcription factors in D. melanogaster is sufficient to induce transcription of p38Kb and enhances resistance to oxidative stress. We further found that the presence of a putative lola-PT binding site in the p38Kb locus of a given species is predictive of the species' survival in response to oxidative stress. Through our comparative genomics approach, we have identified biologically relevant putative transcription factor binding sites that regulate the expression of p38Kb and are associated with resistance to oxidative stress. These findings reveal a novel mode of regulation for p38K genes and suggest that transcription may play as important a role in p38K-mediated stress responses as post-translational modifications.

scholarly journals The transcription factor TAL1 and miR-17-92 create a regulatory loop in hematopoiesis

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Annekarin Meyer ◽  
Stefanie Herkt ◽  
Heike Kunze-Schumacher ◽  
Nicole Kohrs ◽  
Julia Ringleb ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Transcription Factors ◽  
Malignant Disease ◽  
Expression Patterns ◽  
Gene Activation ◽  
Erythroid Differentiation ◽  
Mature Micrornas ◽  
Gene Regulatory ◽  
Regulatory Loop ◽  
Transcriptional Complex

AbstractA network of gene regulatory factors such as transcription factors and microRNAs establish and maintain gene expression patterns during hematopoiesis. In this network, transcription factors regulate each other and are involved in regulatory loops with microRNAs. The microRNA cluster miR-17-92 is located within the MIR17HG gene and encodes six mature microRNAs. It is important for hematopoietic differentiation and plays a central role in malignant disease. However, the transcription factors downstream of miR-17-92 are largely elusive and the transcriptional regulation of miR-17-92 is not fully understood. Here we show that miR-17-92 forms a regulatory loop with the transcription factor TAL1. The miR-17-92 cluster inhibits expression of TAL1 and indirectly leads to decreased stability of the TAL1 transcriptional complex. We found that TAL1 and its heterodimerization partner E47 regulate miR-17-92 transcriptionally. Furthermore, miR-17-92 negatively influences erythroid differentiation, a process that depends on gene activation by the TAL1 complex. Our data give example of how transcription factor activity is fine-tuned during normal hematopoiesis. We postulate that disturbance of the regulatory loop between TAL1 and the miR-17-92 cluster could be an important step in cancer development and progression.

scholarly journals Cytokine-mediated increases in fetal hemoglobin are associated with globin gene histone modification and transcription factor reprogramming

Blood ◽  
2009 ◽  
Vol 114 (11) ◽  
pp. 2299-2306 ◽  
Author(s):  
Orapan Sripichai ◽  
Christine M. Kiefer ◽  
Natarajan V. Bhanu ◽  
Toshihiko Tanno ◽  
Seung-Jae Noh ◽  
...  
Keyword(s):  
Signal Transduction ◽  
Transcription Factor ◽  
Transcription Factors ◽  
Protein Expression ◽  
Histone Modification ◽  
Globin Gene ◽  
Expression Patterns ◽  
Fetal Hemoglobin ◽  
Transcriptome Profiling ◽  
Globin Genes

Abstract Therapeutic regulation of globin genes is a primary goal of translational research aimed toward hemoglobinopathies. Signal transduction was used to identify chromatin modifications and transcription factor expression patterns that are associated with globin gene regulation. Histone modification and transcriptome profiling were performed using adult primary CD34+ cells cultured with cytokine combinations that produced low versus high levels of gamma-globin mRNA and fetal hemoglobin (HbF). Embryonic, fetal, and adult globin transcript and protein expression patterns were determined for comparison. Chromatin immunoprecipitation assays revealed RNA polymerase II occupancy and histone tail modifications consistent with transcriptional activation only in the high-HbF culture condition. Transcriptome profiling studies demonstrated reproducible changes in expression of nuclear transcription factors associated with high HbF. Among the 13 genes that demonstrated differential transcript levels, 8 demonstrated nuclear protein expression levels that were significantly changed by cytokine signal transduction. Five of the 8 genes are recognized regulators of erythropoiesis or globin genes (MAFF, ID2, HHEX, SOX6, and EGR1). Thus, cytokine-mediated signal transduction in adult erythroid cells causes significant changes in the pattern of globin gene and protein expression that are associated with distinct histone modifications as well as nuclear reprogramming of erythroid transcription factors.

scholarly journals Use of Degradation Tags To Control Protein Levels in the Cyanobacterium Synechocystis sp. Strain PCC 6803

2013 ◽  
Vol 79 (8) ◽  
pp. 2833-2835 ◽  
Author(s):  
Brian P. Landry ◽  
Jana Stöckel ◽  
Himadri B. Pakrasi
Keyword(s):  
Fluorescent Protein ◽  
Yellow Fluorescent Protein ◽  
Terminal Protein ◽  
Enhanced Yellow Fluorescent Protein ◽  
Content Type ◽  
Protein Levels ◽  
Steady State Fluorescence ◽  
Tunable Range ◽  
Control Protein ◽  
Synechocystis Sp

ABSTRACTWe generated a collection ofssrA-based C-terminal protein degradation tags with different degradation strengths. The steady-state fluorescence levels of different enhanced yellow fluorescent protein (eYFP) tag variants in aSynechocystissp. indicated a tunable range from 1% to 50% of untagged eYFP.

scholarly journals Transcriptome profilings reveal the candidate genes, pathways and transcription factors related to nitrogen utilization and excessive nitrogen stress in perennial ryegrass.

2020 ◽  
Author(s):  
Yinruizhi Li ◽  
Mengdi Wang ◽  
Ke Teng ◽  
Di Dong ◽  
Zhuocheng Liu ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Transcription Factors ◽  
Perennial Ryegrass ◽  
Expression Patterns ◽  
Enrichment Analysis ◽  
Nitrogen Utilization ◽  
Utilization Rate ◽  
Nitrogen Stress ◽  
Molecular Response ◽  
Stress Effect

Abstract Background：Lolium perenne L. is a kind of high quality forage grass, which can provide a good nutritional basis for herbivorous livestock. However, how to improve the nitrogen utilization rate of ryegrass and avoid the nitrate toxicity caused by excessive nitrogen has been troubling people for a long time. Up to now, the molecular response mechanism of ryegrass to nitrogen is not clear, especially under the condition of excessive nitrogen. Based on this, we tried to obtain a new insight into molecular response of ryegrass in nitrogen utilization and excessive nitrogen stress, providing the molecular theoretical basis for solving this problem.Results: In this study, the transcription of perennial ryegrass at different nitrogen levels was identified by high-throughput next-generation DNA sequencing. Phenotypic characterizations investigated that ryegrass in treatment N0.5 has a better growth state than the other three groups. The treatment N1 and N10 contained excessive nitrogen, which had a stress effect on plant growth. Analysis of differentially expressed genes indicated that 345, 105 genes are considered to involve in the regulation of nitrogen utilization and excessive nitrogen stress, respectively. GO enrichment analysis revealed that plant response to nitrogen mainly enrich in two categories, including “biological process” and “molecular function”. KEGG enrichment analysis suggested that “Photosynthesis-antenna proteins” may respond positively to nitrogen under appropriate nitrogen conditions, whereas “steroid biosynthesis”, “carotenoid biosynthesis” and “C5-branched dibasic acid metabolism” had been identified as top significant enrichment pathways response to excessive nitrogen. Transcription factors analysis showed that 21 TFs related to nitrogen utilization were classified into 10 transcription factor families, especially AP2-EREBP and MYB TF families. 4 TFs related to excessive nitrogen stress were identified, which belonged to 4 transcription factor families including LOB, NAC, AP2-EREBP and HB. The expression patterns of these selected genes above were also analyzed. Conclusions: These results made a contribution to comprehend the molecular mechanism of perennial ryegrass response to nitrogen. It provides new ideas for guiding the production practice and variety improvement of forage and even food crops from the perspective of molecular biology.

scholarly journals CmMYB#7, an R3 MYB transcription factor, acts as a negative regulator of anthocyanin biosynthesis in chrysanthemum

2019 ◽  
Vol 70 (12) ◽  
pp. 3111-3123 ◽  
Author(s):  
Lili Xiang ◽  
Xiaofen Liu ◽  
Heng Li ◽  
Xueren Yin ◽  
Donald Grierson ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Transcription Factors ◽  
Binding Site ◽  
Transient Expression ◽  
Regulatory Mechanism ◽  
Anthocyanin Biosynthesis ◽  
Expression Patterns ◽  
Negative Regulator ◽  
Myb Transcription Factor ◽  
Anthocyanin Content

Abstract ‘Jimba’, a well-known white flowered chrysanthemum cultivar, occasionally and spontaneously produces red colored petals under natural cultivation, but there is little information about the molecular regulatory mechanism underlying this process. We analysed the expression patterns of 91 MYB transcription factors in ‘Jimba’ and ‘Turning red Jimba’ and identified an R3 MYB, CmMYB#7, whose expression was significantly decreased in ‘Turning red Jimba’ compared with ‘Jimba’, and confirmed it is a passive repressor of anthocyanin biosynthesis. CmMYB#7 competed with CmMYB6, which together with CmbHLH2 is an essential component of the anthocyanin activation complex, for interaction with CmbHLH2 through the bHLH binding site in the R3 MYB domain. This reduced binding of the CmMYB6–CmbHLH2 complex and inhibited its ability to activate CmDFR and CmUFGT promoters. Moreover, using transient expression assays we demonstrated that changes in the expression of CmMYB#7 accounted for alterations in anthocyanin content. Taken together, our findings illustrate that CmMYB#7 is a negative regulator of anthocyanin biosynthesis in chrysanthemum.

Granulocytes do not express but acquire monocyte-derived tissue factor in whole blood: evidence for a direct transfer

Blood ◽  
2008 ◽  
Vol 111 (3) ◽  
pp. 1208-1216 ◽  
Author(s):  
Elena M. Egorina ◽  
Mikhail A. Sovershaev ◽  
Jan O. Olsen ◽  
Bjarne Østerud
Keyword(s):  
Tissue Factor ◽  
Whole Blood ◽  
Small Interfering Rna ◽  
Fluorescent Protein ◽  
No Reduction ◽  
Yellow Fluorescent Protein ◽  
Direct Transfer ◽  
Unanimous Opinion ◽  
Protein Levels ◽  
Interfering Rna

AbstractUnlike unanimous opinion on tissue factor (TF) expression in monocytes, the quest for TF presence in granulocytes has been going on for decades. To study the cell origin and track the blood-borne TF, we assessed TF activity and protein levels, knocked-down endogenous TF expression with small interfering RNA (siRNA), and overexpressed TF–yellow fluorescent protein (TF-YFP) fusion in immunologically isolated human monocytes and granulocytes. Monocytes and, to a much lesser extent, granulocytes isolated from lipopolysaccharide (LPS)/phorbol 12-myristate-13-acetate (PMA)–stimulated whole blood contained active TF antigen. However, only monocytes possessed significant TF activity and protein levels when stimulated with LPS/PMA in suspension. Reintroduction of TF-silenced monocytes to whole blood led to a profound reduction of LPS/PMA-stimulated TF activity in both mononuclear cell (MNC) and granulocyte fractions. No reduction in TF activity in MNC and granulocyte fractions was observed when TF-silenced granulocytes were reintroduced to whole blood. As shown by immunoblotting, flow cytometry, and confocal microscopy, granulocytes became positive for TF-YFP when isolated from whole blood reconstituted with TF-YFP–expressing monocytes. Together, we pinpoint monocytes as a major source of TF and provide solid experimental evidence for a direct transfer of TF protein from the monocytes to granulocytes in the blood.

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