Differential phosphorylation and localization of the transcription factor UBF in vivo in response to serum deprivation. In vitro dephosphorylation of UBF reduces its transactivation properties.

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.

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Integrin α3β1 Promotes Invasive and Metastatic Properties of Breast Cancer Cells through Induction of the Brn-2 Transcription Factor

Cancers ◽

10.3390/cancers13030480 ◽

2021 ◽

Vol 13 (3) ◽

pp. 480

Author(s):

Rakshitha Pandulal Miskin ◽

Janine S. A. Warren ◽

Abibatou Ndoye ◽

Lei Wu ◽

John M. Lamar ◽

...

Keyword(s):

Breast Cancer ◽

Transcription Factor ◽

Cancer Cells ◽

Cell Invasion ◽

Breast Cancer Cells ◽

Gene Promoter ◽

Akt Inhibitor ◽

Integrin Α3β1

In the current study, we demonstrate that integrin α3β1 promotes invasive and metastatic traits of triple-negative breast cancer (TNBC) cells through induction of the transcription factor, Brain-2 (Brn-2). We show that RNAi-mediated suppression of α3β1 in MDA-MB-231 cells caused reduced expression of Brn-2 mRNA and protein and reduced activity of the BRN2 gene promoter. In addition, RNAi-targeting of Brn-2 in MDA-MB-231 cells decreased invasion in vitro and lung colonization in vivo, and exogenous Brn-2 expression partially restored invasion to cells in which α3β1 was suppressed. α3β1 promoted phosphorylation of Akt in MDA-MB-231 cells, and treatment of these cells with a pharmacological Akt inhibitor (MK-2206) reduced both Brn-2 expression and cell invasion, indicating that α3β1-Akt signaling contributes to Brn-2 induction. Analysis of RNAseq data from patients with invasive breast carcinoma revealed that high BRN2 expression correlates with poor survival. Moreover, high BRN2 expression positively correlates with high ITGA3 expression in basal-like breast cancer, which is consistent with our experimental findings that α3β1 induces Brn-2 in TNBC cells. Together, our study demonstrates a pro-invasive/pro-metastatic role for Brn-2 in breast cancer cells and identifies a role for integrin α3β1 in regulating Brn-2 expression, thereby revealing a novel mechanism of integrin-dependent breast cancer cell invasion.

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Thymoquinone, a Dietary Bioactive Compound, Exerts Anti-Inflammatory Effects in Colitis by Stimulating Expression of the Colonic Epithelial PPAR-γ Transcription Factor

Nutrients ◽

10.3390/nu13041343 ◽

2021 ◽

Vol 13 (4) ◽

pp. 1343

Author(s):

Balaji Venkataraman ◽

Saeeda Almarzooqi ◽

Vishnu Raj ◽

Abdullah T. Alhassani ◽

Ahmad S. Alhassani ◽

...

Keyword(s):

Transcription Factor ◽

Activity Index ◽

Nigella Sativa ◽

Mapk Signaling ◽

Mitogen Activated Protein Kinase ◽

Ppar Γ ◽

Anti Inflammatory ◽

Ht 29

Inflammatory bowel diseases (IBD) are chronic inflammatory disorders with increasing incidence and prevalence worldwide. Here, we investigated thymoquinone (TQ), a naturally occurring phytochemical present in Nigella sativa, for anti-inflammatory effects in colonic inflammation. To address this, we used in vivo (mice) and in vitro (HT-29 cells) models in this investigation. Our results showed that TQ treatment significantly reduced the disease activity index (DAI), myeloperoxidase (MPO) activity, and protected colon microscopic architecture. In addition, TQ also reduced the expression of proinflammatory cytokines and mediators at both the mRNA and protein levels. Further, TQ decreased phosphorylation of the activated mitogen-activated protein kinase (MAPK) signaling pathway and nuclear factor kappa B (NF-κB) proteins and enhanced colon epithelial PPAR-γ transcription factor expression. TQ significantly decreased proinflammatory chemokines (CXCL-1 and IL-8), and mediator (COX-2) mRNA expression in HT-29 cells treated with TNF-α. TQ also increased HT-29 PPAR-γ mRNA, PPAR-γ protein expression, and PPAR-γ promoter activity. These results indicate that TQ inhibits MAPK and NF-κB signaling pathways and transcriptionally regulates PPAR-γ expression to induce potent anti-inflammatory activity in vivo and in vitro models of colon inflammation.

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Progression and Differentiation of Alveolar Rhabdomyosarcoma Is Regulated by PAX7 Transcription Factor—Significance of Tumor Subclones

Cells ◽

10.3390/cells10081870 ◽

2021 ◽

Vol 10 (8) ◽

pp. 1870

Author(s):

Klaudia Skrzypek ◽

Grażyna Adamek ◽

Marta Kot ◽

Bogna Badyra ◽

Marcin Majka

Keyword(s):

Transcription Factor ◽

Cell Lines ◽

Migration Activity ◽

Id Proteins ◽

Rh30 Cell ◽

Str Profile ◽

And Migration

Rhabdomyosarcoma (RMS), is the most frequent soft tissue tumor in children that originates from disturbances in differentiation process. Mechanisms leading to the development of RMS are still poorly understood. Therefore, by analysis of two RMS RH30 cell line subclones, one subclone PAX7 negative, while the second one PAX7 positive, and comparison with other RMS cell lines we aimed at identifying new mechanisms crucial for RMS progression. RH30 subclones were characterized by the same STR profile, but different morphology, rate of proliferation, migration activity and chemotactic abilities in vitro, as well as differences in tumor morphology and growth in vivo. Our analysis indicated a different level of expression of adhesion molecules (e.g., from VLA and ICAM families), myogenic microRNAs, such as miR-206 and transcription factors, such as MYOD, MYOG, SIX1, and ID. Silencing of PAX7 transcription factor with siRNA confirmed the crucial role of PAX7 transcription factor in proliferation, differentiation and migration of RMS cells. To conclude, our results suggest that tumor cell lines with the same STR profile can produce subclones that differ in many features and indicate crucial roles of PAX7 and ID proteins in the development of RMS.

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RIP3 impedes transcription factor EB to suppress autophagic degradation in septic acute kidney injury

Cell Death and Disease ◽

10.1038/s41419-021-03865-8 ◽

2021 ◽

Vol 12 (6) ◽

Author(s):

Ruizhao Li ◽

Xingchen Zhao ◽

Shu Zhang ◽

Wei Dong ◽

Li Zhang ◽

...

Keyword(s):

Acute Kidney Injury ◽

Transcription Factor ◽

Nuclear Translocation ◽

Kidney Injury ◽

Septic Acute Kidney Injury ◽

Transcription Factor Eb ◽

Autophagic Degradation ◽

Lps Treatment

AbstractAutophagy is an important renal-protective mechanism in septic acute kidney injury (AKI). Receptor interacting protein kinase 3 (RIP3) has been implicated in the renal tubular injury and renal dysfunction during septic AKI. Here we investigated the role and mechanism of RIP3 on autophagy in septic AKI. We showed an activation of RIP3, accompanied by an accumulation of the autophagosome marker LC3II and the autophagic substrate p62, in the kidneys of lipopolysaccharide (LPS)-induced septic AKI mice and LPS-treated cultured renal proximal tubular epithelial cells (PTECs). The lysosome inhibitor did not further increase the levels of LCII or p62 in LPS-treated PTECs. Moreover, inhibition of RIP3 attenuated the aberrant accumulation of LC3II and p62 under LPS treatment in vivo and in vitro. By utilizing mCherry-GFP-LC3 autophagy reporter mice in vivo and PTECs overexpression mRFP-GFP-LC3 in vitro, we observed that inhibition of RIP3 restored the formation of autolysosomes and eliminated the accumulated autophagosomes under LPS treatment. These results indicated that RIP3 impaired autophagic degradation, contributing to the accumulation of autophagosomes. Mechanistically, the nuclear translocation of transcription factor EB (TFEB), a master regulator of the lysosome and autophagy pathway, was inhibited in LPS-induced mice and LPS-treated PTECs. Inhibition of RIP3 restored the nuclear translocation of TFEB in vivo and in vitro. Co-immunoprecipitation further showed an interaction of RIP3 and TFEB in LPS-treated PTECs. Also, the expression of LAMP1 and cathepsin B, two potential target genes of TFEB involved in lysosome function, were decreased under LPS treatment in vivo and in vitro, and this decrease was rescued by inhibiting RIP3. Finally, overexpression of TFEB restored the autophagic degradation in LPS-treated PTECs. Together, the present study has identified a pivotal role of RIP3 in suppressing autophagic degradation through impeding the TFEB-lysosome pathway in septic AKI, providing potential therapeutic targets for the prevention and treatment of septic AKI.

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Arsenic Directly Binds to and Activates the Yeast AP-1-Like Transcription Factor Yap8

Molecular and Cellular Biology ◽

10.1128/mcb.00842-15 ◽

2015 ◽

Vol 36 (6) ◽

pp. 913-922 ◽

Cited By ~ 17

Author(s):

Nallani Vijay Kumar ◽

Jianbo Yang ◽

Jitesh K. Pillai ◽

Swati Rawat ◽

Carlos Solano ◽

...

Keyword(s):

Transcription Factor ◽

Transcriptional Activation ◽

Transcriptional Response ◽

Transcriptional Regulator ◽

Yeast Protein ◽

Content Type ◽

Arsenic Tolerance ◽

Arsenic Sensing

The AP-1-like transcription factor Yap8 is critical for arsenic tolerance in the yeastSaccharomyces cerevisiae. However, the mechanism by which Yap8 senses the presence of arsenic and activates transcription of detoxification genes is unknown. Here we demonstrate that Yap8 directly binds to trivalent arsenite [As(III)]in vitroandin vivoand that approximately one As(III) molecule is bound per molecule of Yap8. As(III) is coordinated by three sulfur atoms in purified Yap8, and our genetic and biochemical data identify the cysteine residues that form the binding site as Cys132, Cys137, and Cys274. As(III) binding by Yap8 does not require an additional yeast protein, and Yap8 is regulated neither at the level of localization nor at the level of DNA binding. Instead, our data are consistent with a model in which a DNA-bound form of Yap8 acts directly as an As(III) sensor. Binding of As(III) to Yap8 triggers a conformational change that in turn brings about a transcriptional response. Thus, As(III) binding to Yap8 acts as a molecular switch that converts inactive Yap8 into an active transcriptional regulator. This is the first report to demonstrate how a eukaryotic protein couples arsenic sensing to transcriptional activation.

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Activation of the heat shock transcription factor by hypoxia in normal and tumor cell lines in vivo and in vitro

International Journal of Radiation Oncology*Biology*Physics ◽

10.1016/0360-3016(92)90667-7 ◽

1992 ◽

Vol 23 (4) ◽

pp. 891-897 ◽

Cited By ~ 19

Author(s):

Amato J. Giaccia ◽

Elizabeth A. Auger ◽

Albert Koong ◽

David J. Terris ◽

Andrew I. Minchinton ◽

...

Keyword(s):

Transcription Factor ◽

Heat Shock ◽

Tumor Cell ◽

Cell Lines ◽

Heat Shock Transcription Factor ◽

Tumor Cell Lines

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MicroRNA-17-92 Regulates the Transcription Factor E2F3b during Myogenesis In Vitro and In Vivo

International Journal of Molecular Sciences ◽

10.3390/ijms18040727 ◽

2017 ◽

Vol 18 (4) ◽

pp. 727 ◽

Cited By ~ 7

Author(s):

Zhixiong Tang ◽

Nian Liu ◽

Lan Luo ◽

Kang Kang ◽

Li Li ◽

...

Keyword(s):

Transcription Factor

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Role for the Ran Binding Protein, Mog1p, in Saccharomyces cerevisiae SLN1-SKN7 Signal Transduction

Eukaryotic Cell ◽

10.1128/ec.3.6.1544-1556.2004 ◽

2004 ◽

Vol 3 (6) ◽

pp. 1544-1556 ◽

Cited By ~ 17

Author(s):

Jade Mei-Yeh Lu ◽

Robert J. Deschenes ◽

Jan S. Fassler

Keyword(s):

Signal Transduction ◽

Transcription Factor ◽

Osmotic Stress ◽

Kinase Activity ◽

Mitogen Activated Protein Kinase ◽

Osmotic Response ◽

Mitogen Activated Protein ◽

Kinase Pathway

ABSTRACT Yeast Sln1p is an osmotic stress sensor with histidine kinase activity. Modulation of Sln1 kinase activity in response to changes in the osmotic environment regulates the activity of the osmotic response mitogen-activated protein kinase pathway and the activity of the Skn7p transcription factor, both important for adaptation to changing osmotic stress conditions. Many aspects of Sln1 function, such as how kinase activity is regulated to allow a rapid response to the continually changing osmotic environment, are not understood. To gain insight into Sln1p function, we conducted a two-hybrid screen to identify interactors. Mog1p, a protein that interacts with the yeast Ran1 homolog, Gsp1p, was identified in this screen. The interaction with Mog1p was characterized in vitro, and its importance was assessed in vivo. mog1 mutants exhibit defects in SLN1-SKN7 signal transduction and mislocalization of the Skn7p transcription factor. The requirement for Mog1p in normal localization of Skn7p to the nucleus does not fully account for the mog1-related defects in SLN1-SKN7 signal transduction, raising the possibility that Mog1p may play a role in Skn7 binding and activation of osmotic response genes.

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Transcription Factor STE12α Has Distinct Roles in Morphogenesis, Virulence, and Ecological Fitness of the Primary Pathogenic Yeast Cryptococcus gattii

Eukaryotic Cell ◽

10.1128/ec.00009-06 ◽

2006 ◽

Vol 5 (7) ◽

pp. 1065-1080 ◽

Cited By ~ 37

Author(s):

Ping Ren ◽

Deborah J. Springer ◽

Melissa J. Behr ◽

William A. Samsonoff ◽

Sudha Chaturvedi ◽

...

Keyword(s):

Transcription Factor ◽

Gene Knockout ◽

Natural Habitat ◽

Cryptococcus Gattii ◽

Human Neutrophils ◽

Knockout Mutant ◽

Pathogenic Yeast ◽

Ecological Fitness

ABSTRACT Cryptococcus gattii is a primary pathogenic yeast, increasingly important in public health, but factors responsible for its host predilection and geographical distribution remain largely unknown. We have characterized C. gattii STE12α to probe its role in biology and pathogenesis because this transcription factor has been linked to virulence in many human and plant pathogenic fungi. A full-length STE12α gene was cloned by colony hybridization and sequenced using primer walk and 3′ rapid amplification of cDNA ends strategies, and a ste12αΔ gene knockout mutant was created by URA5 insertion at the homologous site. A semiquantitative analysis revealed delayed and poor mating in ste12αΔ mutant; this defect was not reversed by exogenous cyclic AMP. C. gattii parent and mutant strains showed robust haploid fruiting. Among putative virulence factors tested, the laccase transcript and enzymatic activity were down regulated in the ste12αΔ mutant, with diminished production of melanin. However, capsule, superoxide dismutase, phospholipase, and urease were unaffected. Similarly, Ste12 deficiency did not cause any auxotrophy, assimilation defects, or sensitivity to a large panel of chemicals and antifungals. The ste12αΔ mutant was markedly attenuated in virulence in both BALB/c and A/Jcr mice models of meningoencephalitis, and it also exhibited significant in vivo growth reduction and was highly susceptible to in vitro killing by human neutrophils (polymorphonuclear leukocytes). In tests designed to simulate the C. gattii natural habitat, the ste12αΔ mutant was poorly pigmented on wood agar prepared from two tree species and showed poor survival and multiplication in wood blocks. Thus, STE12α plays distinct roles in C. gattii morphogenesis, virulence, and ecological fitness.

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