scholarly journals Novel Insights for PI3KC3 in Mediating Lipid Accumulation in Yellow Catfish Pelteobagrus Fulvidraco

2021 ◽  
Author(s):  
Mei-Qin Zhuo ◽  
Jun Chen ◽  
Mei-Li Wu ◽  
Wen-biao Wang
Keyword(s):  
Transcriptional Regulation ◽  
Protein Level ◽  
Lipid Accumulation ◽  
Mrna Level ◽  
Pelteobagrus Fulvidraco ◽  
Yellow Catfish ◽  
Site Mutation ◽  
Mobility Shift ◽  
Mobility Shift Assay ◽  
Mutation Assay

Abstract In this study, the transcriptional regulation of PI3KC3 by three transcript factors (PPARγ, PPARα and STAT3) and the potential role of PI3KC3 in mediating lipid accumulation were determined in yellow catfish Pelteobagrus fulvidraco. The 5’-deletion assay, overexpression assay, site-mutation assay and electrophoretic mobility shift assay suggested that PPARα, PPARγ and STAT3 negatively regulated the promoter activity of pi3kc3. Moreover, the transcriptional inactivation of pi3kc3 was directly mediated by PPARα and PPARγ under fatty acid (FA) treatment. Using primary hepatocytes from yellow catfish, FA incubation significantly increased triacylglyceride (TG), NEFA content, the mRNA level of pparα, pparγ, stat3 and dnmt3b, the protein level of PPARα, PPARγ and STAT3, and the methylation level of pi3kc3, but significantly reduced the mRNA and protein level of PI3KC3. Our findings offer new insights into the mechanisms for transcriptional regulation of PI3KC3 and for PI3KC3-mediated lipid accumulation in fish.

scholarly journals Functional Analysis of Steroidogenic Factor 1 (sf-1) and 17α-Hydroxylase/Lyase (cyp17α) Promoters in Yellow Catfish Pelteobagrus fulvidraco

2020 ◽  
Vol 22 (1) ◽  
pp. 195
Author(s):  
Wu-Hong Lv ◽  
Guang-Hui Chen ◽  
Mei-Qin Zhuo ◽  
Yi-Huan Xu ◽  
Yi-Chuang Xu ◽  
...  
Keyword(s):  
Binding Sites ◽  
Promoter Activity ◽  
Pelteobagrus Fulvidraco ◽  
Peroxisome Proliferator ◽  
Yellow Catfish ◽  
Site Mutation ◽  
Promoter Regions ◽  
Mobility Shift ◽  
Peroxisome Proliferator Activated Receptor ◽  
Steroidogenic Factor 1

The present study was performed to clone and characterize the structures and functions of steroidogenic factor 1 (sf-1) and 17α-hydroxylase/lyase (cyp17α) promoters in yellow catfish Pelteobagrus fulvidraco, a widely distributed freshwater teleost. We successfully obtained 1981 and 2034 bp sequences of sf-1 and cyp17α promoters, and predicted the putative binding sites of several transcription factors, such as Peroxisome proliferator-activated receptor alpha (PPARα), Peroxisome proliferator-activated receptor gamma (PPARγ) and Signal transducer and activator of transcription 3 (STAT3), on sf-1 and cyp17α promoter regions, respectively. Overexpression of PPARγ significantly increased the activities of sf-1 and cyp17α promoters, but overexpression of PPARα significantly decreased the promoter activities of sf-1 and cyp17α. Overexpression of STAT3 reduced the activity of the sf-1 promoter but increased the activity of the cyp17α promoter. The analysis of site-mutation and electrophoretic mobility shift assay suggested that the sf-1 promoter possessed the STAT3 binding site, but did not the PPARα or PPARγ binding sites. In contrast, only the PPARγ site, not PPARα or STAT3 sites, was functional with the cyp17α promoter. Leptin significantly increased sf-1 promoter activity, but the mutation of STAT3 and PPARγ sites decreased leptin-induced activation of sf-1 promoter. Our findings offered the novel insights into the transcriptional regulation of sf-1 and cyp17α and suggested leptin regulated sf-1 promoter activity through STAT3 site in yellow catfish.

scholarly journals Transcriptional regulation of human and murine 17β-hydroxysteroid dehydrogenase type-7 confers its participation in cholesterol biosynthesis

2006 ◽  
Vol 37 (1) ◽  
pp. 185-197 ◽  
Author(s):  
Thomas Ohnesorg ◽  
Brigitte Keller ◽  
Martin Hrabé de Angelis ◽  
Jerzy Adamski
Keyword(s):  
Transcriptional Regulation ◽  
Binding Sites ◽  
Sequence Similarity ◽  
Regulatory Element ◽  
Cholesterol Biosynthesis ◽  
Hydroxysteroid Dehydrogenase ◽  
Site Directed Mutagenesis ◽  
Mobility Shift ◽  
Mobility Shift Assay

In both humans and mice, 17β-hydroxysteroid dehydrogenase type-7 (HSD17B7) was described as possessing dual enzymatic functionality. The enzyme was first shown to be able to convert estrone to estradiol in vitro. Later involvement of this enzyme in postsqualene cholesterol biosynthesis was postulated (conversion of zymosterone to zymosterol) and could be proven in vitro. In this work, we performed a detailed analysis of the transcriptional regulation of both the human and murine genes. Despite relatively low sequence similarity, both promoters contain similar contexts of transcription factor-binding sites. The participation of these sites in transcriptional regulation of HSD17B7 was proven by electro-mobility shift assay and site-directed mutagenesis of the corresponding binding sites. We describe novel involvement of vitamin D receptor/retinoid X receptor and provide new information on the regulation of HSD17B7 expression by sterol regulatory element-binding protein and hepatocyte nuclear factor 4, the latter known from other genes of cholesterogenic enzymes. The results of our study provide unequivocal evidence for a role of HSD17B7 in cholesterol biosynthesis.

scholarly journals Downregulation of PU.1 Leads to Decreased Expression of Dectin-1 in Alveolar Macrophages during Pneumocystis Pneumonia

2010 ◽  
Vol 78 (3) ◽  
pp. 1058-1065 ◽  
Author(s):  
Chen Zhang ◽  
Shao-Hung Wang ◽  
Chung-Ping Liao ◽  
Shoujin Shao ◽  
Mark E. Lasbury ◽  
...  
Keyword(s):  
Alveolar Macrophages ◽  
Mrna Level ◽  
Gene Promoter ◽  
Pneumocystis Pneumonia ◽  
Luciferase Reporter ◽  
Mrna Levels ◽  
Dependent Manner ◽  
Luciferase Reporter Gene ◽  
Mobility Shift ◽  
Mobility Shift Assay

ABSTRACT Dectin-1 is an important macrophage phagocytic receptor recognizing fungal β-glucans. In this study, the mRNA levels of the Dectin-1 gene were found to be decreased by 61% in alveolar macrophages (AMs) from Pneumocystis-infected mice. The expression of Dectin-1 protein on the surface of these cells was also significantly decreased. By fluorescence in situ hybridization, mRNA expression levels of the transcription factor PU.1 were also found to be significantly reduced in AMs from Pneumocystis-infected mice. Electrophoretic mobility shift assay showed that PU.1 protein bound Dectin-1 gene promoter. With a luciferase reporter gene driven by the Dectin-1 gene promoter, the expression of the PU.1 gene in NIH 3T3 cells was found to enhance the luciferase activity in a dose-dependent manner. PU.1 expression knockdown by small interfering RNA (siRNA) caused a 63% decrease in Dectin-1 mRNA level and 40% decrease in protein level in AMs. Results of this study indicate that downregulation of PU.1 during Pneumocystis pneumonia leads to decreased expression of Dectin-1 in AMs.

scholarly journals Role of MexZ and PA5471 in transcriptional regulation of mexXY in Pseudomonas aeruginosa

Microbiology ◽  
2009 ◽  
Vol 155 (10) ◽  
pp. 3312-3321 ◽  
Author(s):  
Masaki Yamamoto ◽  
Atsuhisa Ueda ◽  
Makoto Kudo ◽  
Yasuhiro Matsuo ◽  
Jun Fukushima ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Transcriptional Regulation ◽  
Molecular Mechanisms ◽  
Efflux Pump ◽  
Mobility Shift ◽  
Drug Induced ◽  
Drug Efflux Pump ◽  
Mobility Shift Assay

MexXY, a drug efflux pump in Pseudomonas aeruginosa, confers resistance to aminoglycoside antibiotics. We recently reported that MexZ binds to the promoter region of the mexXY operon. Electrophoretic mobility shift assay (EMSA) using recombinant MexZ and oligonucleotide probes prepared from the intergenic region between mexZ and mexX revealed that MexZ binds to a 20 bp palindromic sequence. Culture of P. aeruginosa in the presence of tetracycline induced higher levels of MexX and MexZ, as measured by immunoblotting and EMSA, than in the absence of antibiotics. When MexZ was expressed by a mexZ expression plasmid, the plasmid-borne MexZ repressed drug-induced MexX production, further confirming that MexZ acts as a repressor of the mexXY operon. PA5471 protein has been reported to be essential for drug-induced MexXY production. Similarly to that report, we observed that plasmid-borne PA5471 induced both MexX and MexZ production in PAO1 cells. Interestingly, interaction between MexZ and PA5471 was observed in a yeast two-hybrid assay. Furthermore, EMSA and in vitro transcription assays revealed that interaction between PA5471 and MexZ reduced MexZ DNA-binding ability, leading to mexXY transcription. These findings contribute to the understanding of the molecular mechanisms underlying the transcriptional regulation of mexZ and mexXY by drug-induced PA5471 expression.

scholarly journals Runx3 negatively regulates Osterix expression in dental pulp cells

2007 ◽  
Vol 405 (1) ◽  
pp. 69-75 ◽  
Author(s):  
Li Zheng ◽  
Koichiro Iohara ◽  
Masaki Ishikawa ◽  
Takeshi Into ◽  
Teruko Takano-Yamamoto ◽  
...  
Keyword(s):  
Transcriptional Regulation ◽  
Dental Pulp ◽  
Tooth Development ◽  
Tooth Germ ◽  
Dental Pulp Cells ◽  
Mobility Shift ◽  
Pulp Cells ◽  
Mobility Shift Assay ◽  
Responsive Element

Osterix, a zinc-finger-containing transcription factor, is required for osteoblast differentiation and bone formation. Osterix is also expressed in dental mesenchymal cells of the tooth germ. However, transcriptional regulation by Osterix in tooth development is not clear. Genetic studies in osteogenesis place Osterix downstream of Runx2 (Runt-related 2). The expression of Osterix in odontoblasts overlaps with Runx3 during terminal differentiation in vivo. Runx3 down-regulates Osterix expression in mouse DPCs (dental pulp cells). Therefore the regulatory role of Runx3 on Osterix expression in tooth development was investigated. Enforced expression of Runx3 down-regulated the activity of the Osterix promoter in the human embryonic kidney 293 cell line. When the Runx3 responsive element on the Osterix promoter, located at −713 to −707 bp (site 3, AGTGGTT) relative to the cap site, was mutated, this down-regulation was abrogated. Furthermore, electrophoretic mobility-shift assay and chromatin immunoprecipitation assays in mouse DPCs demonstrated direct functional binding of Runx3 to the Osterix promoter. These results demonstrate the transcriptional regulation of Osterix expression by Runx3 during differentiation of dental pulp cells into odontoblasts during tooth development.

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