scholarly journals Ca2+-Dependent Regulation of Calcitonin Gene Expression by the Transcriptional Repressor DREAM

Endocrinology ◽  
2006 ◽  
Vol 147 (10) ◽  
pp. 4608-4617 ◽  
Author(s):  
Miho Matsuda ◽  
Tada-aki Yamamoto ◽  
Masato Hirata
Keyword(s):  
Gene Expression ◽  
Molecular Mechanisms ◽  
Regulatory Element ◽  
Transcriptional Repressor ◽  
Calcium Ionophore ◽  
Luciferase Assay ◽  
Dependent Manner ◽  
Wild Type ◽  
Stable Transfectants ◽  
Tt Cells

Calcitonin (CT), whose secretion from thyroid glands is regulated by increases in the concentration of extracellular Ca2+, is a well-known hormone that regulates calcium homeostasis. However, the molecular mechanisms underlying the gene expression dependent on Ca2+ have not been clarified. The downstream regulatory element (DRE) antagonist modulator (DREAM) was recently identified as a Ca2+-dependent transcriptional repressor. In the present study, we investigated the possible involvement of DREAM in the regulation of CT gene expression and secretion. A luciferase assay using TT cells, a thyroid carcinoma cell line, showed that a particular region in the CT gene promoter repressed the promoter activity under basal conditions but induced the activity when the Ca2+ concentration was increased. We found two DRE sequences in a region located upstream from the transcription start site. Gel retardation assay confirmed that DREAM bound to the CT-DRE and also indicated that DREAM bound to the DRE in a Ca2+-dependent manner. We generated stable transfectants of TT cells with wild-type or mutant DREAM, which lacked the responsiveness to Ca2+ changes. In contrast to the wild type, overexpression of the mutant DREAM inhibited the increase in CT secretion induced by a calcium ionophore. The addition of forskolin to increase cAMP activated the CT promoter, probably by the interaction of DREAM with cAMP-responsive element binding proteins, independent on the activation by Ca2+. Together, these results suggest that DREAM plays an important role in human CT gene expression in a Ca2+- and cAMP-dependent manner.

scholarly journals FNDC4 Inhibits RANKL-Induced Osteoclast Formation by Suppressing NF-κB Activation and CXCL10 Expression

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Zheng-tao Lv ◽  
Shuang Liang ◽  
Kun Chen ◽  
Jia-ming Zhang ◽  
Peng Cheng ◽  
...  
Keyword(s):  
Gene Expression ◽  
Bone Resorption ◽  
Molecular Mechanisms ◽  
Osteoclast Differentiation ◽  
Differentially Expressed Gene ◽  
Osteoclast Formation ◽  
Luciferase Assay ◽  
Raw 264.7 Cells ◽  
Inflammatory Factor ◽  
Dependent Manner

FNDC4 acts as an anti-inflammatory factor on macrophages and improves mouse model of induced colitis. Considering osteoclast formation is characterized by the activation of inflammation-related pathways, we thus speculated that FNDC4 may play a pivotal role in this process. RT-qPCR analysis was performed to confirm the expression of osteoclast formation related genes in primary murine bone marrow macrophages (BMMs). RANKL-treated BMMs were cultured with FNDC4 to evaluate the effect of FNDC4 on osteoclast differentiation. TRAP staining and bone resorption pits assay were used to assess osteoclast formation and bone resorption, respectively. Luciferase assay and western blotting analysis were conducted to determine whether FNDC4 inhibited osteoclast formation via NF-κB signaling in RAW 264.7 cells. Furthermore, to identify gene signatures in FNDC4-treated BMMs and to use these to elucidate the underlying molecular mechanisms during osteoclast formation, we adopted a bioinformatics approach by downloading the GSE76172 gene expression profiling dataset from the Gene Expression Omnibus (GEO) database. FNDC4 inhibited RANKL-induced osteoclastogenesis and mature osteoclast resorptive function in a dose-dependent manner. Results of NF-κB luciferase assay suggested that FNDC4 could significantly suppress the RANKL-induced NF-κB transcriptional activity. Based on the protein-protein interaction network, CXCL10 was identified as the differentially expressed gene with the highest connectivity degree (degree = 23); it was drastically downregulated in the presence of FNDC4, but supplementation of CXCL10 (10 ng/mL) partially ameliorated the FNDC4-induced inhibition of osteoclast formation. Taken together, we speculated that FNDC4 could suppress osteoclast formation via NF-κB pathway and downregulation of CXCL10.

scholarly journals Tomato wall-associated kinase SlWak1 acts in an Fls2- and Fls3-dependent manner to promote apoplastic immune responses to Pseudomonas syringae

2020 ◽  
Author(s):  
Ning Zhang ◽  
Marina A Pombo ◽  
Hernan G Rosli ◽  
Gregory B Martin
Keyword(s):  
Gene Expression ◽  
Immune Responses ◽  
Pseudomonas Syringae ◽  
Molecular Mechanisms ◽  
Plant Immunity ◽  
Transcript Abundance ◽  
Dependent Manner ◽  
Wild Type ◽  
Disease Symptoms

Wall-associated kinases (Waks) are known to be important components of plant immunity against various pathogens including Pseudomonas syringae pv. tomato (Pst) although their molecular mechanisms are largely unknown. In tomato, SlWak1 has been implicated in immunity because its transcript abundance increases significantly in leaves after treatment with the flagellin-derived peptides flg22 and flgII-28, which activate the receptors Fls2 and Fls3, respectively. We generated two SlWak1 tomato mutants (Δwak1) using CRISPR/Cas9 and investigated the role of SlWak1 in tomato-Pst interactions. PTI activated in the apoplast by flg22 or flgII-28 was compromised in Δwak1 plants but PTI at the leaf surface was unaffected. The Δwak1 plants developed fewer callose deposits than wild-type plants but retained the ability to generate reactive oxygen species and activate MAPKs in response to flg22 and flgII-28. The induction of Wak1 gene expression by flg22 and flgII-28 was greatly reduced in a tomato mutant lacking Fls2 and Fls3 but induction of Fls3 gene expression by flgII-28 was unaffected in Δwak1 plants. After Pst inoculation, Δwak1 plants developed disease symptoms more slowly than Δfls2.1/fls2.2/fls3 mutant plants, although both plants ultimately were similarly susceptible. SlWak1 co-immunoprecipitated with both Fls2 and Fls3 independently of flg22/flgII-28 or Bak1. These observations suggest that SlWak1 acts in a complex with Fls2/Fls3 and plays an important role at later stages of the PTI in the apoplast.

scholarly journals An unusual genomic position effect on Drosophila white gene expression: pairing dependence, interactions with zeste, and molecular analysis of revertants.

Genetics ◽  
1992 ◽  
Vol 130 (1) ◽  
pp. 125-138 ◽  
Author(s):  
T Hazelrigg ◽  
S Petersen
Keyword(s):  
Gene Expression ◽  
Regulatory Element ◽  
Position Effect ◽  
Insertion Site ◽  
White Gene ◽  
Chromosome 2 ◽  
Wild Type ◽  
Gene Copies ◽  
In Trans ◽  
In Cis

Abstract The white gene in the AR4-24 P[white,rosy] insertion on chromosome 2 has a novel expression pattern, in which it is repressed in the dorsal half of the eye. X-ray mutagenesis led to the isolation of six revertants mapping to chromosome 2, which are wild type in a zeste+ background, and three extreme derivatives, in which white gene expression is repressed in ventral regions of the eye as well. By Southern blot analyses the breakpoints of five of the revertants and one of the extreme derivatives were mapped in the flanking DNA bordering each side of the AR4-24 insertion. The revertants show some dorsal repression of white in the presence of z1, and by this criterion each is only a partial revertant. The extreme derivatives act not only in cis, but also in trans to repress expression of AR4-24 and its various derivatives. We provide evidence that these trans effects are proximity-dependent effects, possibly mediated by pairing of gene copies, as they do not extend to copies of the white gene located elsewhere in the genome. We show that one extreme derivative, E1, is a small deletion spanning the insertion site at the 5' end of the white gene, and propose that the distance between a negative regulatory element in the 5' flanking DNA and the white promoter influences the degree of the repression.

Methanol Extract of Mongolian Iris bungei Maxim. Stimulates 3T3-L1 Adipocyte Differentiation

2021 ◽  
Vol 21 (7) ◽  
pp. 3943-3949
Author(s):  
Jaegoo Yeon ◽  
Sung-Suk Suh ◽  
Ui-Joung Youn ◽  
Badamtsetseg Bazarragchaa ◽  
Ganbold Enebish ◽  
...  
Keyword(s):  
Bacterial Infections ◽  
Fatty Acid Synthase ◽  
Molecular Mechanisms ◽  
Adipocyte Differentiation ◽  
Methanol Extract ◽  
Regulatory Element ◽  
Peroxisome Proliferator ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Peroxisome Proliferator Activated Receptor

Iris bungei Maxim. (IB), which is native to China and Mongolia, is used as a traditional medicine for conditions such as inflammation, cancer, and bacterial infections. However, the effects of Iris bungei Maxim. on adipocyte differentiation have not been studied. In the present study, we first demonstrated the molecular mechanisms underlying the adipogenic activity of the methanol extract of Mongolian I. bungei Maxim. (IB). IB significantly enhanced intracellular lipid accumulation and adipocyte differentiation in 3T3-L1 preadipocytes in a concentration-dependent manner. Moreover, IB markedly stimulated the expression of genes related to adipogenesis such as peroxisome proliferator-activated receptor γ, adiponectin, and aP2. In addition, we also observed that IB induces lipogenic genes such as fatty acid synthase, sterol regulatory element binding protein 1c, stearoyl-CoA desaturase, and acetyl-CoA carboxylase. Interestingly IB regulated adipocyte differentiation in both the early and middle stages. Taken together, these adipogenic and lipogenic effects of IB suggest its efficacy for the prevention and/or treatment of type 2 diabetes.

A calcineurin- and NFAT-dependent pathway regulates Myf5 gene expression in skeletal muscle reserve cells

2001 ◽  
Vol 114 (2) ◽  
pp. 303-310 ◽  
Author(s):  
B.B. Friday ◽  
G.K. Pavlath
Keyword(s):  
Gene Expression ◽  
Skeletal Muscle ◽  
Satellite Cell ◽  
Cell Activation ◽  
Molecular Mechanisms ◽  
Fiber Type ◽  
Calcium Ionophore ◽  
Cell Populations ◽  
Mrna Levels ◽  
Dependent Pathway

Myf5 is a member of the muscle regulatory factor family of transcription factors and plays an important role in the determination, development, and differentiation of skeletal muscle. However, factors that regulate the expression and activity of Myf5 itself are not well understood. Recently, a role for the calcium-dependent phosphatase calcineurin was suggested in three distinct pathways in skeletal muscle: differentiation, hypertrophy, and fiber-type determination. We propose that one downstream target of calcineurin and the calcineurin substrate NFAT in skeletal muscle is regulation of Myf5 gene expression. For these studies, we used myotube cultures that contain both multinucleated myotubes and quiescent, mononucleated cells termed ‘reserve’ cells, which share many characteristics with satellite cells. Treatment of such myotube cultures with the calcium ionophore ionomycin results in an approximately 4-fold increase in Myf5 mRNA levels, but similar effects are not observed in proliferating myoblast cultures indicating that Myf5 is regulated by different pathways in different cell populations. The increase in Myf5 mRNA levels in myotube cultures requires the activity of calcineurin and NFAT, and can be specifically enhanced by overexpressing the NFATc isoform. We used immunohistochemical analyses and fractionation of the cell populations to demonstrate that the calcium regulated expression of Myf5 occurs in the mononucleated reserve cells. We conclude that Myf5 gene expression is regulated by a calcineurin- and NFAT-dependent pathway in the reserve cell population of myotube cultures. These results may provide important insights into the molecular mechanisms responsible for satellite cell activation and/or the renewal of the satellite cell pool following activation and proliferation.

CircRNA circ-0110102 Function as Anti-oncogenic Gene in Hepatocellular Carcinoma through Modulating miR-580-5p/CCL2 Pathway

2020 ◽  
Author(s):  
Xinxing Wang ◽  
Wei Sheng ◽  
Tao Xu ◽  
Jiawen Xu ◽  
Juntao Chen ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Molecular Mechanisms ◽  
Tumor Biology ◽  
Luciferase Assay ◽  
Migration And Invasion ◽  
Circular Rnas ◽  
Dependent Manner ◽  
Activation Effect ◽  
Cox 2 ◽  
No Activation

Abstract Background Circular RNAs (circRNAs) have been shown to have critical regulatory roles in tumor biology, whereas their contributions in hepatocellular carcinoma (HCC) still remains enigmatic. The purpose of this study was to investigate the molecular mechanisms involved in hsa_circ_0110102 in the occurrence and development of HCC. Results hsa_circ_0110102 was significantly down-regulated in HCC cell lines and tissues, low hsa_circ_0110102 expression levels were associated with poor prognosis. Knockdown hsa_circ_0110102 significantly inhibited cell proliferation, migration and invasion. In addition, the interaction between hsa_circ_0110102 and miR-580-5p was predicted and verified by luciferase assay and RNA pull-down, indicating that hsa_circ_0110102 function as sponge of miR-580-5p. Moreover, miR-580-5p which could directly bind to the 3’-UTR of CCL2 and induce its expression, then active the COX-2/PGE2 pathway in macrophage via FoxO1 in p38 MAPK dependent manner. Furthermore, the Δ256 mutant of FoxO1 showed no activation effect. These results concluded that hsa_circ_0110102 act as a sponge for miR-580-5p and decreased CCL2 secretion in HCC cells, then inhibits pro-inflammatory cytokine release from activated macrophage by regulating the COX-2/PGE2 pathway. Conclusions These results indicating that hsa_circ_0110102 serves as a potential prognostic predictor or therapeutic target for HCC.

The rmc locus does not affect plant interactions or defence-related gene expression when tomato (Solanum lycopersicum) is infected with the root fungal parasite, Rhizoctonia

2006 ◽  
Vol 33 (3) ◽  
pp. 289 ◽  
Author(s):  
Ling-Ling Gao ◽  
F. Andrew Smith ◽  
Sally E. Smith
Keyword(s):  
Gene Expression ◽  
Molecular Mechanisms ◽  
Arbuscular Mycorrhizal ◽  
Am Fungi ◽  
Fungal Species ◽  
Plant Interactions ◽  
Related Gene ◽  
Wild Type ◽  
Cell Layers ◽  
Almost All

A tomato mutant with reduced mycorrhizal colonisation, rmc, confers resistance to almost all arbuscular mycorrhizal (AM) fungal species tested, although there is variation in colonisation of different root cell layers by different fungi and one species of AM fungus can colonise this mutant relatively normally. These variations indicate a high degree of specificity in relation to AM colonisation. We explored the possibility of specificity or otherwise in interactions between rmc and three non-AM root-infecting fungi, Rhizoctonia solani anastomosis groups (AG) 4 and AG8, and binucleate Rhizoctonia (BNR). There were no differences between the wild type tomato 76R and rmc in the speed or extent to which these fungi infected roots or caused disease. Infection by R. solani induced high levels of defence-related gene expression in both tomato genotypes relative to non-infected plants. In contrast, with BNR the expression of these genes was not induced or induced to a much lower extent than with R. solani. The expression of defence-related genes with these two non-AM fungi was very similar in the two plant genotypes. It was different from effects observed during colonisation by AM fungi, which enhanced expression of defence-related genes in rmc compared with the wild type tomato. The specificity and molecular mechanisms of rmc in control of AM colonisation are discussed.

scholarly journals Effects on Liver Lipid Metabolism of the Naturally Occurring Dietary Flavone Luteolin-7-glucoside

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Carla Sá ◽  
Ana Rita Oliveira ◽  
Cátia Machado ◽  
Marisa Azevedo ◽  
Cristina Pereira-Wilson
Keyword(s):  
Lipid Metabolism ◽  
Fatty Acid Synthase ◽  
Molecular Mechanisms ◽  
Metabolic Diseases ◽  
Regulatory Element ◽  
Lipid Lowering ◽  
Whole Body ◽  
Mrna Levels ◽  
Dependent Manner ◽  
Hepatic Expression

Disruptions in whole-body lipid metabolism can lead to the onset of several pathologies such as nonalcoholic fatty liver disease (NAFLD) and cardiovascular diseases (CVDs). The present study aimed at elucidating the molecular mechanisms behind the lipid-lowering effects of the flavone luteolin-7-glucoside (L7G) which we previously showed to improve plasma lipid profile in rats. L7G is abundant in plant foods of Mediterranean diet such as aromatic plants used as herbs. Results show that dietary supplementation with L7G for one week induced the expression of peroxisome proliferator-activated receptor-alpha (PPAR-α) and of its target gene carnitine palmitoyl transferase 1 (CPT-1) in rat liver. L7G showed a tendency to decrease the hepatic expression of sterol regulatory element-binding protein-1 (SREBP-1), without affecting fatty acid synthase (FAS) protein levels. Although SREBP-2 and LDLr mRNA levels did not change, the expression of HMG CoA reductase (HMGCR) was significantly repressed by L7G. L7G also inhibited this enzyme’sin vitroactivity in a dose dependent manner, but only at high and not physiologically relevant concentrations. These results add new evidence that the flavone luteolin-7-glucoside may help in preventing metabolic diseases and clarify the mechanisms underlying the beneficial health effects of diets rich in fruits and vegetables.

scholarly journals The Ubiquitin Carboxyl Hydrolase BAP1 Forms a Ternary Complex with YY1 and HCF-1 and Is a Critical Regulator of Gene Expression

2010 ◽  
Vol 30 (21) ◽  
pp. 5071-5085 ◽  
Author(s):  
Helen Yu ◽  
Nazar Mashtalir ◽  
Salima Daou ◽  
Ian Hammond-Martel ◽  
Julie Ross ◽  
...  
Keyword(s):  
Gene Expression ◽  
Ternary Complex ◽  
Transcriptional Control ◽  
Molecular Mechanisms ◽  
Mitochondrial Protein ◽  
Coiled Coil ◽  
Dependent Manner ◽  
Cellular Processes ◽  
Rich Domain

ABSTRACT The candidate tumor suppressor BAP1 is a deubiquitinating enzyme (DUB) involved in the regulation of cell proliferation, although the molecular mechanisms governing its function remain poorly defined. BAP1 was recently shown to interact with and deubiquitinate the transcriptional regulator host cell factor 1 (HCF-1). Here we show that BAP1 assembles multiprotein complexes containing numerous transcription factors and cofactors, including HCF-1 and the transcription factor Yin Yang 1 (YY1). Through its coiled-coil motif, BAP1 directly interacts with the zinc fingers of YY1. Moreover, HCF-1 interacts with the middle region of YY1 encompassing the glycine-lysine-rich domain and is essential for the formation of a ternary complex with YY1 and BAP1 in vivo. BAP1 activates transcription in an enzymatic-activity-dependent manner and regulates the expression of a variety of genes involved in numerous cellular processes. We further show that BAP1 and HCF-1 are recruited by YY1 to the promoter of the cox7c gene, which encodes a mitochondrial protein used here as a model of BAP1-activated gene expression. Our findings (i) establish a direct link between BAP1 and the transcriptional control of genes regulating cell growth and proliferation and (ii) shed light on a novel mechanism of transcription regulation involving ubiquitin signaling.

scholarly journals Nrg1 Is a Transcriptional Repressor for Glucose Repression of STA1 Gene Expression inSaccharomyces cerevisiae

1999 ◽  
Vol 19 (3) ◽  
pp. 2044-2050 ◽  
Author(s):  
Seok Hee Park ◽  
Sang Seok Koh ◽  
Jae Hwan Chun ◽  
Hye Jin Hwang ◽  
Hyen Sam Kang
Keyword(s):  
Gene Expression ◽  
Zinc Finger Protein ◽  
Glucose Repression ◽  
Transcriptional Repressor ◽  
Dependent Manner ◽  
Expression Of Genes ◽  
Dnase I Footprinting ◽  
Genes Encoding

ABSTRACT Expression of genes encoding starch-degrading enzymes is regulated by glucose repression in the yeast Saccharomyces cerevisiae. We have identified a transcriptional repressor, Nrg1, in a genetic screen designed to reveal negative factors involved in the expression of STA1, which encodes a glucoamylase. TheNRG1 gene encodes a 25-kDa C2H2zinc finger protein which specifically binds to two regions in the upstream activation sequence of the STA1 gene, as judged by gel retardation and DNase I footprinting analyses. Disruption of theNRG1 gene causes a fivefold increase in the level of theSTA1 transcript in the presence of glucose. The expression of NRG1 itself is inhibited in the absence of glucose. DNA-bound LexA-Nrg1 represses transcription of a target gene 10.7-fold in a glucose-dependent manner, and this repression is abolished in bothssn6 and tup1 mutants. Two-hybrid and glutathione S-transferase pull-down experiments show an interaction of Nrg1 with Ssn6 both in vivo and in vitro. These findings indicate that Nrg1 acts as a DNA-binding repressor and mediates glucose repression of the STA1 gene expression by recruiting the Ssn6-Tup1 complex.

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