1.Progress of study on the transcription factor SALL4.
Jiang LIN ; Run-Bi JI ; Jun QIAN
Journal of Experimental Hematology 2011;19(3):820-823
SAL-like 4 (SALL4) locating at chromosome 20q13.13-13.2 encodes a newly identified transcription factor containing 8 zinc finger motif. Recent studies have revealed the important role of SALL4 gene in the regulation of early embryonic development, organogenesis, and proliferation and pluripotency of embryonic stem cells. The heterozygous mutations of SALL4 in different loci, causing nonsense mutation or frameshift mutation, and resulting in genesis of premature terminal codon, are correlated with autosomal dominant hereditary diseases such as Okihiro syndrome, acro-renal-ocular syndrome and IVIC syndrome. The level of SALL4 expression is increased in germ cell tumors, hepatoid gastric carcinoma, acute myeloid leukemia, B-precursor cell leukemia/lymphoma and myelodysplastic syndrome. This review focuses on the structure and function of SALL4 gene as well as its relevance to related diseases.
Genetic Diseases, Inborn
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genetics
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Humans
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Mutation
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Transcription Factors
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genetics
2.The transcriptional regulation study on human delta globin gene with CAAT box C-->T point mutation in its promoter.
Jie YAO ; Song-sen CHEN ; Ke-gong YANG ; Xu DI ; An-qi XIONG ; You-hong ZHANG
Acta Academiae Medicinae Sinicae 2002;24(2):140-143
OBJECTIVETo study the transcriptional regulation of human delta globin gene with C-->T point mutation at -64 in its promoter.
METHODSHuman delta globin genes including wild CAAT box and mutant CAAT box (-64C-->T) were separately cloned into eukaryotic expression vector pcDNA3.1 (-)/Myc-His A which was cut out the strong promoter CMV, transfected MEL cells, and induced by DMSO to express. The transcriptional regulation of human delta globin gene was analysed using semi-quantitative RT-PCR.
RESULTSThe expression level of human delta globin gene with mutant CAAT box was 2.2-fold as high as that with wild CAAT box.
CONCLUSIONThe defective CAAT box of human delta globin gene promoter region may be one of the major reasons for its low expression level.
CCAAT-Enhancer-Binding Proteins ; genetics ; Globins ; genetics ; Humans ; Point Mutation ; Promoter Regions, Genetic ; genetics ; Transcription, Genetic
4.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
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Humans
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Trans-Activators
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genetics
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metabolism
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Transcription Factors
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genetics
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metabolism
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Transcription, Genetic
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Transcriptional Activation
6.Expression of growth-factor independence 1 in patients with leukemia and its significance.
Tian-Tian WANG ; Zi-Xing CHEN ; Jian-Nong CEN ; Jun HE ; Hong-Jie SHENG ; Li YAO
Journal of Experimental Hematology 2010;18(4):834-837
This study was purposed to investigate the expression of the growth-factor independence 1 (GFI1) in patients with leukemia and its clinical significance. Bone marrow mononuclear cells were obtained from 65 newly diagnosed leukemia patients including 24 acute myeloid leukemia (AML), 18 chronic myelogenous leukemia (CML), 6 acute lymphoblastic leukemia (ALL), 17 blast crisis of chronic myelogenous leukemia and 13 patients with iron deficiency anemia (IDA) were used as controls. The relative expression of gene gfi1 was detected by reverse transcriptase-polymerase chain reaction (RT-PCR) and taqman quantitative real-time reverse transcription polymerase chain reaction (QRT-PCR). The results showed that gene expression of gene gfi1 in leukemia patients was obviously higher than that in controls and the difference was statistically significant (p < 0.01), in which the expression of gene gfi1 in newly diagnosed CML patients was higher than that in newly diagnosed AML, newly diagnosed ALL, CML-BCP patients and the difference was significant (p < 0.01). Expression of gene gfi1 in lymphocytic blast crisis of CML was higher than that in nonlymphocytic blast crisis of CML, and the difference was significant. It is concluded that gene gfi1 may play an important role in leukemia, especially in CML incidence and progression. The high level expression of gene gfi1 may be participate in the development of lymphoma.
DNA-Binding Proteins
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genetics
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Gene Expression
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Humans
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Leukemia
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genetics
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Reverse Transcriptase Polymerase Chain Reaction
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Transcription Factors
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genetics
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Transcription, Genetic
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genetics
8.Effect of overexpressing Nisin A structural gene nisA on Nisin A production.
Miaomiao FAN ; Yimin QIU ; Chen LIU ; Zhixia JI ; Xin MA ; Yi YU ; Shouwen CHEN
Chinese Journal of Biotechnology 2012;28(10):1175-1183
Nisin is an antimicrobial peptide widely used in food industry. In this study, Nisin A production in Lactococcus lactis ATCC 11454 was improved by overexpression of Nisin A structural gene nisA through introducing a shuttle expression vector pMG36ek-nisA and an integrated vector pDG780-nisA into the host strain. The differences of growth profiles and Nisin A production level between the two obtained genetic engineering strains FMM1/FMM2 and the parent strain were investigated. Our results show that while the growth profile (the growth rate, biomass and pH) of FMM1 was similar to the parent strain, its Nisin A production increased 31%. In contrast, the biomass of FMM2 was notably lower than the parent strain, while its yield of Nisin A enhanced slightly. The transcription level of genes involved in Nisin A biosynthesis in both engineering strains was further detected by RT-PCR. We found that all the 11 Nisin A biosynthetic genes in FMM1 and FMM2 had a higher transcription level than those in the parent strain, and these genes exhibited more significant increasing degree of transcription level in FMM1 which hosted the autonomous replicating nisA gene. These data suggest that expression of nisA may act as a rate-limit factor in Nisin A biosynthesis. In conclusion, this work provides a new method to improve Nisin A production by increasing the transcription level of nisA, paving the way to further large-scale industrial production of Nisin A.
Bacterial Proteins
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genetics
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Genes, Bacterial
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Genetic Engineering
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Genetic Vectors
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Lactococcus lactis
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genetics
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metabolism
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Nisin
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biosynthesis
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genetics
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Transcription, Genetic
9.Directed evolution of promoter and cellular transcription machinery and its application in microbial metabolic engineering--a review.
Xinqing ZHAO ; Rujiao JIANG ; Fengwu BAI
Chinese Journal of Biotechnology 2009;25(9):1312-1315
Directed evolution, which is also called molecular evolution, or artificial evolution, combines random mutagenesis and directed selection. In previous studies, it has been extensively applied for the improvement of enzyme catalytic properties and stability, as well as the expanding of substrate specificity. In recent years, directed evolution was also employed in metabolic engineering of promoters for improving their strength and function, and the engineering of global transcription machinery. These techniques contribute to breeding more tolerant strains against environmental stress, as well as strains with improved fermentation efficiency. In this article, we reviewed the applications of directed evolution in the metabolic engineering of promoters and global transcription machinery. These techniques enabled fine-tuning of gene expression and simultaneous alternation of multiple gene transcription inside the cells, and thus are powerful new tools for metabolic engineering.
Directed Molecular Evolution
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Genetic Engineering
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Industrial Microbiology
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methods
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Metabolism
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Promoter Regions, Genetic
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genetics
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Saccharomyces cerevisiae
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genetics
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Transcription, Genetic
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genetics