1.Mutations in various functional domains of HPV2 E2 protein inhibit the transcriptional depression activities.
Chen GAO ; Yan-Jun LEI ; Hui-Ying JIANG ; Qi SHI ; Chan TIAN ; Jun HAN ; Xiao-Ping DONG
Chinese Journal of Experimental and Clinical Virology 2011;25(3):164-166
OBJECTIVETo study the potential transcriptional depression activities of HPV2 E2 proteins with mutations in different functional domains.
METHODSThe primers for constructing various E2 mutants were synthesized based on a HPV2 isolate containing several point mutations within E2 open reading frame. Different E2 mutations were generated by the method of extending PCR and inserted into plasmid pcDNA3. 1. Various recombinant mammalian expression plasmids pcDNA3. 1-E2 were co-transfected into HeLa cells together with a CAT-reporter plasmid pBLCAT-LCR containing HPV-2 prototype LCR, respectively. The transcriptional repression activities of the E2 mutants were evaluated by detection of CAT expression values.
RESULTSCompared with the full-length prototype E2, removals of both N- and C-terminal domains abolished E2 transcriptional repressive activities. The point mutations in the transactivation domain (nt 3037), the internal hinge region (nt 3387) and DNA binding domain (nt 3697) showed remarkable inhibition on its transcriptional depression function.
CONCLUSIONThe transcriptional regulation activity of HPV2 E2 is related with its DNA binding and transactivation domains. The exchanges of the single amino acid within E2, derived from a HPV2 isolate, abolish significantly the repressive effect on viral promoter in the context of full-length E2.
HeLa Cells ; Humans ; Oncogene Proteins, Viral ; genetics ; Papillomaviridae ; genetics ; Promoter Regions, Genetic ; genetics ; Transcriptional Activation ; genetics
2.Screening of the target genes transactivated by PS1TP1 protein with suppression subtractive hybridization technique.
Hui-Huang HUANG ; Dong JI ; Si-Yu WANG ; Wan-Zhen XU ; Zhi-Yuan JIA ; Ke LI
Chinese Journal of Experimental and Clinical Virology 2011;25(3):179-181
OBJECTIVETo construct a subtractive cDNA library of genes transactivated by PS1TP1 protein with suppression subtractive hybridization (SSH) technique.
METHODSSuppression subtractive hybridization technique and bioinformatics technique were used, the mRNA from HepG2 cells transfected with pcDNA3.1 (-) -PS1TP1 and pcDNA3. 1 (-) empty vector was isolated, respectively; cDNA underwent two times of nested PCR, amplified cDNA fragments were subcloned into pGEM-Teasy vectors to set up the subtractive library.
RESULTSThe subtractive library of genes transactivated by PS1TP1 was constructed successfully. Sequence analysis was performed in 43 clones randomly, and the full length sequences were obtained with bioinformatics method and searched for homologous DNA sequence from GenBank, altogether 12 coding sequences were gotten, which consisted of 10 known and 2 unknown ones.
CONCLUSIONThe obtained sequences may be target genes transactivated by PS1TP1 protein among which some genes coding proteins involved in cell cycle regulation, metabolism, immunity and cell apoptosis. This finding brought some clues for studying the biological functions of PS1T1.
Hepatitis B ; genetics ; Humans ; Nucleic Acid Hybridization ; methods ; Transcriptional Activation ; genetics ; Viral Proteins ; genetics
3.Expression of microRNA-107 in hepatocellular carcinoma and its clinical significance.
Lu-Shan XIAO ; Xue-Jing ZOU ; Wei HU ; Li LIU
Journal of Southern Medical University 2016;36(7):974-978
OBJECTIVETo investigate the expression of microRNA-107 (miR-107) and its functional role in hepatocellular carcinoma(HCC).
METHODSThe gene chip data of HCC obtained from the Gene Expression Omnibus (GEO) database and the Cancer Genome Atlas (TCGA) database were used to analyze the expression levels of miR-107 in liver cancer. Twenty-two pairs of fresh surgical specimens of HCC and adjacent tissues and 53 paraffin-embedded specimens of HCC were examined for miR-107 expression by qRT-PCR. The correlation of the expression levels of miR-107 with the clinicopathologic characteristics of the patients were analyzed. The role of miR-107 in regulating the proliferation of hepatocellular carcinoma cells were determined by MTT assay in Huh7 cells transfected with a miR-107 mimic or inhibitor.
RESULTSThe expression levels of miR-107 were significantly up-regulated in HCC tissues as compared to the adjacent tissues (P<0.05) in positive correlation with the tumor size (P<0.032). Transfection with miR-107 mimics significantly promoted the cell proliferation (P<0.0001) while miR-107 inhibitor inhibited the cell proliferation (P<0.0001).
CONCLUSIONThe expression of miR-107 is up- regulated in HCC tissues and its expression levels are correlated with HCC cell proliferation, suggesting its role as a potential oncogene in liver cancer.
Carcinoma, Hepatocellular ; genetics ; Cell Proliferation ; Humans ; Liver Neoplasms ; genetics ; MicroRNAs ; genetics ; Transcriptional Activation ; Up-Regulation
4.Study on the transcriptional activation of MTS1 gene beta promoter.
Wen-li FENG ; Xing LIU ; Zhi-guang TU ; Zong-gan HUANG
Chinese Journal of Hematology 2003;24(7):344-346
OBJECTIVETo investigate the effect of MTS1 gene beta promoter transcriptional activation in T-cell acute lymphoblastic leukemia (T-ALL) cell lines and identify the fragment with transcriptional activation.
METHODSSeven pGL3 recombinant plasmids with the same 3'-end transcriptional start site but the different 5'sequences were constructed by gene recombinant technique and transfected into Jurkat cell line which is biallelic deletion of MTS1 gene by transient transfection. Luciferase report gene was detected to observe beta promoter transcriptional activation.
RESULTSSeven pGL3 recombinant plasmids containing different fragments of beta promoter were obtained, all of them showed transcriptional activation in Jurkat cell line. Among them, the 0.38 kb fragment cut by SacII-SacI is fundamental in transcription.
CONCLUSIONMTS1 gene beta promoter can be activated in Jurkat cell line.
Genes, p16 ; Humans ; Jurkat Cells ; Plasmids ; genetics ; Promoter Regions, Genetic ; genetics ; Transcriptional Activation ; Transfection
5.Transcriptional activators and activation mechanisms.
Protein & Cell 2011;2(11):879-888
Transcriptional activators are required to turn on the expression of genes in a eukaryotic cell. Activators bound to the enhancer can facilitate either the recruitment of RNA polymerase II to the promoter or its elongation. This article examines a few selected issues in understanding activator functions and activation mechanisms.
Animals
;
Humans
;
Trans-Activators
;
genetics
;
metabolism
;
Transcription Factors
;
genetics
;
metabolism
;
Transcription, Genetic
;
Transcriptional Activation
6.Transcriptional repression by androgen receptor: roles in castration-resistant prostate cancer.
Galina GRITSINA ; Wei-Qiang GAO ; Jindan YU
Asian Journal of Andrology 2019;21(3):215-223
Androgen receptor (AR), a hormonal transcription factor, plays important roles during prostate cancer progression and is a key target for therapeutic interventions. While androgen-deprivation therapies are initially successful in regressing prostate tumors, the disease ultimately comes back as castration-resistant prostate cancer (CRPC) or at the late stage as neuroendocrine prostate cancer (NEPC). CRPC remains largely dependent on hyperactive AR signaling in the milieu of low androgen, while NEPC is negative of AR expression but positive of many AR-repressed genes. Recent technological advances in genome-wide analysis of transcription factor binding sites have revealed an unprecedented set of AR target genes. In addition to its well-known function in activating gene expression, AR is increasingly known to also act as a transcriptional repressor. Here, we review the molecular mechanisms by which AR represses gene expression. We also summarize AR-repressed genes that are aberrantly upregulated in CRPC and NEPC and represent promising targets for therapeutic intervention.
Epigenetic Repression
;
Humans
;
Male
;
Prostatic Neoplasms, Castration-Resistant/genetics*
;
Receptors, Androgen/genetics*
;
Transcriptional Activation
7.CRISPR-assisted transcription activation by phase-separation proteins.
Jiaqi LIU ; Yuxi CHEN ; Baoting NONG ; Xiao LUO ; Kaixin CUI ; Zhan LI ; Pengfei ZHANG ; Wenqiong TAN ; Yue YANG ; Wenbin MA ; Puping LIANG ; Zhou SONGYANG
Protein & Cell 2023;14(12):874-887
The clustered regularly interspaced short palindromic repeats (CRISPR)-Cas9 system has been widely used for genome engineering and transcriptional regulation in many different organisms. Current CRISPR-activation (CRISPRa) platforms often require multiple components because of inefficient transcriptional activation. Here, we fused different phase-separation proteins to dCas9-VPR (dCas9-VP64-P65-RTA) and observed robust increases in transcriptional activation efficiency. Notably, human NUP98 (nucleoporin 98) and FUS (fused in sarcoma) IDR domains were best at enhancing dCas9-VPR activity, with dCas9-VPR-FUS IDR (VPRF) outperforming the other CRISPRa systems tested in this study in both activation efficiency and system simplicity. dCas9-VPRF overcomes the target strand bias and widens gRNA designing windows without affecting the off-target effect of dCas9-VPR. These findings demonstrate the feasibility of using phase-separation proteins to assist in the regulation of gene expression and support the broad appeal of the dCas9-VPRF system in basic and clinical applications.
Humans
;
Transcriptional Activation
;
RNA, Guide, CRISPR-Cas Systems
;
Gene Expression Regulation
;
CRISPR-Cas Systems/genetics*
8.Screening and cloning target genes transactivated by hepatitis C virus F protein using suppression subtractive hybridization technique.
Jiang GUO ; Jun CHENG ; Dong JI ; Long-feng ZHAO ; Xue-song GAO ; Yan LIU ; Shun-hua WU
Chinese Journal of Hepatology 2005;13(9):660-663
OBJECTIVESTo identify and clone human genes transactivated by HCV F protein by constructing a cDNA subtractive library using the suppression subtractive hybridization technique.
METHODSSuppression subtractive hybridization (SSH) and bioinformatics techniques were used for screening and cloning of the target genes transactivated by HCV F protein. The mRNA was isolated from HepG2 cells transfected with pcDNA3.1 (-)-F or with pcDNA3.1(-) empty vector as a control, and SSH method was employed to analyze the differentially expressed DNA sequence between the two groups. After restriction enzyme Rsa I digestion, small sized cDNAs were obtained. Then tester cDNA was divided into two groups and ligated to the specific adaptor 1 or adaptor 2. After tester cDNA was hybridized with driver cDNA twice and underwent two times of nested PCR, it was then subcloned into T/A plasmid vectors to set up the subtractive library. Amplification of the library was carried out with E. coli strain DH5 alpha. The cDNA was sequenced and analyzed in GenBank with blast search after PCR.
RESULTSThe subtractive library of genes transactivated by HCV F protein was constructed successfully. The amplified library contains 71 positive clones. Colony PCR shows that 56 clones contain 200-1000 bp inserts. Sequence analysis was performed on 28 clones randomly, and the full length sequences were obtained with using the bioinformatics method. Altogether 19 coding sequences were obtained, consisting of 17 known and 2 unknown.
CONCLUSIONSThe obtained sequences may be target genes transactivated by HCV F protein, and some gene coding proteins are those involved in cell cycle regulation, metabolism, and cell apoptosis.
Cloning, Molecular ; Hepacivirus ; genetics ; Humans ; Nucleic Acid Hybridization ; methods ; RNA, Messenger ; biosynthesis ; genetics ; Transcriptional Activation ; Viral Core Proteins ; biosynthesis ; genetics
9.The assay of transcriptional activation effect of TR3 and deletion mutation in the yeast two hybrid system.
Xin-xing WANG ; Zhi-hua YANG ; Xiao-hua LIU ; Dong-sheng GUO ; Ling-jia QIAN
Chinese Journal of Applied Physiology 2008;24(4):504-507
AIMTo assay the transcriptional activation effect of TR3 and it's deletion mutation in yeast two hybrid system.
METHODSThe total length of TR3 and TR3/delta1-690 gene was amplified by PCR method and cloned into pGBKT7 vector. Bait vector of pGBKT7-TR3 and pGBKT7-TR3/delta1-690 was transformed into AH109 competence yeast. Then self activation of the recombination vector was tested by assay the activity of beta-galactosidae.
RESULTSThe pGBKT7-TR3 and pGBKT7-TR3/AM 690 vector was successfully constructed. The filter paper containing beta-galactosidae didn't changed to blue showed that the reporter gene wasn't activationed.
CONCLUSIONTR3 and TR3/delta1-690 hadn't the activity of transcriptional activation.
Nuclear Receptor Subfamily 4, Group A, Member 1 ; genetics ; physiology ; Sequence Deletion ; Transcriptional Activation ; genetics ; Two-Hybrid System Techniques
10.HIF
Wen TANG ; Tingting LONG ; Fangfang LI ; Cong PENG ; Shuang ZHAO ; Xiang CHEN ; Juan SU
Journal of Central South University(Medical Sciences) 2021;46(4):333-344
OBJECTIVES:
To analyze the expressions and distributions of hypoxia-inducible factor-1α (HIF-1α), CD147, and glucose transporter 1 (GLUT1) in epidermis from psoriasis vulgaris and normal people, and to explore the associations among these proteins and their roles in hypoxic HaCaT cell line.
METHODS:
The expression levels of HIF-1α, CD147, and GLUT1 were determined by immunohistochemistry staining in skin biopsies from 48 psoriasis vularis patients and 33 healthy subjects. Cobalt chloride (CoCl
RESULTS:
HIF-1α, CD147, and GLUT1 were highly expressed and the glycolytic capacity was increased in lesions of psoriasis vulgaris; HIF-1α upregulated the expression of CD147 and GLUT1, increased the lactate production and decreased the ATP level in CoCl
CONCLUSIONS
Glycolytic capacity increases in the injured keratinocytes of psoriasis vulgaris, suggesting that HIF-1α, CD147, and GLUT1 are associated with glycolysis, which can be considered as the promising targets for psoriasis therapy.
Basigin
;
Glucose Transporter Type 1
;
Glycolysis
;
Humans
;
Hypoxia-Inducible Factor 1, alpha Subunit/genetics*
;
Psoriasis/genetics*
;
Transcriptional Activation
;
Up-Regulation