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  1. Article ; Online: Metabolic regulation of an fnr gene knockout Escherichia coli under oxygen limitation.

    Marzan, Lolo Wal / Siddiquee, Khandaker Al Zaid / Shimizu, Kazuyuki

    Bioengineered bugs

    2011  Volume 2, Issue 6, Page(s) 331–337

    Abstract: In addition to our previous study on the effect of fnr gene knockout on the metabolism in Escherichia coli under aerobic conditions (Kumar and Shimizu, Microb Cell Fact 2011), here we further investigated the effect of fnr gene knockout on the metabolism ...

    Abstract In addition to our previous study on the effect of fnr gene knockout on the metabolism in Escherichia coli under aerobic conditions (Kumar and Shimizu, Microb Cell Fact 2011), here we further investigated the effect of fnr gene knockout on the metabolism under micro-aerobic condition based on gene expressions, enzyme activities and intracellular metabolic fluxes. The objective of the present research is to clarify the metabolic regulation mechanism on how the culture environment, such as oxygen level, affects the cell metabolism in relation to gene expressions, enzyme activities and fluxes via global regulators such as Fnr and ArcA/B systems. Under micro-aerobic condition, the flux through Pfl and Frd were reduced for the mutant, which are due to fnr gene knockout. The decreased flux through Pfl may have caused accumulation of PYR, which increased the flux through LDH. The fnr gene knockout caused arcA to be downregulated, and thus the TCA cycle was activated, and cyoA and cydB genes were upregulated. The downregulation of arcA caused lpdA and aceE, F to be upregulated where the flux through PDHc increased. The fnr gene knockout indirectly caused cra gene transcript level to be decreased, which in turn caused the glycolysis genes to be upregulated, which correspond to the increase in the specific glucose consumption rate. The fnr gene knockout also caused crp transcript level to be increased, where there might be some relationship between the two due to similar structure and gene sequence. It may be quite important to understand the metabolic regulation mechanism based on different levels of information for the efficient metabolic engineering and control of the culture environment for process optimization.
    MeSH term(s) Anaerobiosis ; Bacterial Outer Membrane Proteins/genetics ; Bacterial Outer Membrane Proteins/metabolism ; Citric Acid Cycle/genetics ; Escherichia coli/genetics ; Escherichia coli/metabolism ; Escherichia coli Proteins/genetics ; Gene Expression Regulation, Bacterial ; Gene Knockout Techniques ; Glucose/metabolism ; Glycolysis/genetics ; Industrial Microbiology/methods ; Iron-Sulfur Proteins/deficiency ; Iron-Sulfur Proteins/genetics ; Metabolic Engineering/methods ; Oxygen/metabolism ; RNA, Messenger/analysis ; RNA, Messenger/biosynthesis ; Repressor Proteins/genetics ; Repressor Proteins/metabolism
    Chemical Substances Bacterial Outer Membrane Proteins ; Escherichia coli Proteins ; FNR protein, E coli ; Iron-Sulfur Proteins ; RNA, Messenger ; Repressor Proteins ; Glucose (IY9XDZ35W2) ; Oxygen (S88TT14065)
    Language English
    Publishing date 2011-11
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ISSN 1949-1026
    ISSN (online) 1949-1026
    DOI 10.4161/bbug.2.6.16350
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  2. Article ; Online: STAT3 as a target for inducing apoptosis in solid and hematological tumors.

    Al Zaid Siddiquee, Khandaker / Turkson, James

    Cell research

    2008  Volume 18, Issue 2, Page(s) 254–267

    Abstract: Studies in the past few years have provided compelling evidence for the critical role of aberrant Signal Transducer and Activator of Transcription 3 (STAT3) in malignant transformation and tumorigenesis. Thus, it is now generally accepted that STAT3 is ... ...

    Abstract Studies in the past few years have provided compelling evidence for the critical role of aberrant Signal Transducer and Activator of Transcription 3 (STAT3) in malignant transformation and tumorigenesis. Thus, it is now generally accepted that STAT3 is one of the critical players in human cancer formation and represents a valid target for novel anticancer drug design. This review focuses on aberrant STAT3 and its role in promoting tumor cell survival and supporting the malignant phenotype. A brief evaluation of the current strategies targeting STAT3 for the development of novel anticancer agents against human tumors harboring constitutively active STAT3 will also be presented.
    MeSH term(s) Animals ; Antineoplastic Agents/therapeutic use ; Apoptosis/drug effects ; Cell Survival/drug effects ; Cell Transformation, Neoplastic/drug effects ; Cell Transformation, Neoplastic/metabolism ; Drug Design ; Hematologic Neoplasms/drug therapy ; Hematologic Neoplasms/metabolism ; Humans ; STAT3 Transcription Factor/antagonists & inhibitors ; STAT3 Transcription Factor/metabolism
    Chemical Substances Antineoplastic Agents ; STAT3 Transcription Factor ; STAT3 protein, human
    Language English
    Publishing date 2008-01-29
    Publishing country England
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Review
    ZDB-ID 1319303-x
    ISSN 1748-7838 ; 1001-0602
    ISSN (online) 1748-7838
    ISSN 1001-0602
    DOI 10.1038/cr.2008.18
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  3. Article ; Online: Effect of cra gene knockout together with edd and iclR genes knockout on the metabolism in Escherichia coli.

    Sarkar, Dayanidhi / Siddiquee, Khandaker Al Zaid / Araúzo-Bravo, Marcos J / Oba, Takahiro / Shimizu, Kazuyuki

    Archives of microbiology

    2008  Volume 190, Issue 5, Page(s) 559–571

    Abstract: To elucidate the physiological adaptation of Escherichia coli due to cra gene knockout, a total of 3,911 gene expressions were investigated by DNA microarray for continuous culture. About 50 genes were differentially regulated for the cra mutant. TCA ... ...

    Abstract To elucidate the physiological adaptation of Escherichia coli due to cra gene knockout, a total of 3,911 gene expressions were investigated by DNA microarray for continuous culture. About 50 genes were differentially regulated for the cra mutant. TCA cycle and glyoxylate shunt were down-regulated, while pentose phosphate (PP) pathway and Entner Doudoroff (ED) pathway were up-regulated in the cra mutant. The glucose uptake rate and the acetate production rate were increased with less acetate consumption for the cra mutant. To identify the genes controlled by Cra protein, the Cra recognition weight matrix from foot-printing data was developed and used to scan the whole genome. Several new Cra-binding sites were found, and some of the result was consistent with the DNA microarray data. The ED pathway was active in the cra mutant; we constructed cra.edd double genes knockout mutant to block this pathway, where the acetate overflowed due to the down-regulation of aceA,B and icd gene expressions. Then we further constructed cra.edd.iclR triple genes knockout mutant to direct the carbon flow through the glyoxylate pathway. The cra.edd.iclR mutant showed the least acetate production, resulting in the highest cell yield together with the activation of the glycolysis pathway, but the glucose consumption rate could not be improved.
    MeSH term(s) Acetic Acid/metabolism ; Bacterial Proteins/genetics ; Bacterial Proteins/metabolism ; Binding Sites ; Biomass ; Citric Acid Cycle ; DNA, Bacterial/genetics ; Escherichia coli/genetics ; Escherichia coli/metabolism ; Escherichia coli Proteins/genetics ; Escherichia coli Proteins/metabolism ; Gene Deletion ; Gene Expression Profiling ; Gene Expression Regulation, Bacterial ; Glucose/metabolism ; Oligonucleotide Array Sequence Analysis ; Pentose Phosphate Pathway ; Repressor Proteins/genetics ; Repressor Proteins/metabolism
    Chemical Substances Bacterial Proteins ; DNA, Bacterial ; Escherichia coli Proteins ; Repressor Proteins ; IclR protein, E coli (135945-37-8) ; FruR protein, Bacteria (138186-82-0) ; Glucose (IY9XDZ35W2) ; Acetic Acid (Q40Q9N063P)
    Language English
    Publishing date 2008-11
    Publishing country Germany
    Document type Journal Article
    ZDB-ID 124824-8
    ISSN 1432-072X ; 0302-8933
    ISSN (online) 1432-072X
    ISSN 0302-8933
    DOI 10.1007/s00203-008-0406-2
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  4. Article: Effect of a pyruvate kinase (pykF-gene) knockout mutation on the control of gene expression and metabolic fluxes in Escherichia coli.

    Siddiquee, Khandaker Al Zaid / Arauzo-Bravo, Marcos J / Shimizu, Kazuyuki

    FEMS microbiology letters

    2004  Volume 235, Issue 1, Page(s) 25–33

    Abstract: The metabolic regulation of Escherichia coli lacking a functional pykF gene was investigated based on gene expressions, enzyme activities, intracellular metabolite concentrations and the metabolic flux distribution obtained based on (13)C-labeling ... ...

    Abstract The metabolic regulation of Escherichia coli lacking a functional pykF gene was investigated based on gene expressions, enzyme activities, intracellular metabolite concentrations and the metabolic flux distribution obtained based on (13)C-labeling experiments. RT-PCR revealed that the glycolytic genes such as glk, pgi, pfkA and tpiA were down regulated, that ppc, pckA, maeB and mdh genes were strongly up-regulated, and that the oxidative pentose phosphate pathway genes such as zwf and gnd were significantly up-regulated in the pykF mutant. The catabolite repressor/activator gene fruR was up-regulated in the pykF mutant, but the adenylate cyclase gene cyaA was down-regulated indicating a decreased rate of glucose uptake. This was also ascertained by the degradation of ptsG mRNA, the gene for which was down-regulated in the pykF mutant. In general, the changes in enzyme activities more or less correlated with ratios of gene expression, while the changes in metabolic fluxes did not correlate with enzyme activities. For example, high flux ratios were obtained through the oxidative pentose phosphate pathway due to an increased concentration of glucose-6-phosphate rather than to favorable enzyme activity ratios. In contrast, due to decreased availability of pyruvate (and acetyl coenzyme A) in the pykF mutant compared with the wild type, low flux ratios were found through lactate and acetate forming pathways.
    MeSH term(s) Escherichia coli/enzymology ; Escherichia coli/genetics ; Escherichia coli/metabolism ; Gene Deletion ; Gene Expression Regulation, Bacterial ; Genes, Bacterial ; Pyruvate Kinase/genetics
    Chemical Substances Pyruvate Kinase (EC 2.7.1.40)
    Language English
    Publishing date 2004-06-01
    Publishing country England
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 752343-9
    ISSN 1574-6968 ; 0378-1097
    ISSN (online) 1574-6968
    ISSN 0378-1097
    DOI 10.1016/j.femsle.2004.04.004
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  5. Article: Effect of cra gene knockout together with edd and iclR genes knockout on the metabolism in Escherichia coli

    Sarkar, Dayanidhi / Siddiquee, Khandaker Al Zaid / Araúzo-Bravo, Marcos J / Oba, Takahiro / Shimizu, Kazuyuki

    Archives of microbiology. 2008 Nov., v. 190, no. 5

    2008  

    Abstract: To elucidate the physiological adaptation of Escherichia coli due to cra gene knockout, a total of 3,911 gene expressions were investigated by DNA microarray for continuous culture. About 50 genes were differentially regulated for the cra mutant. TCA ... ...

    Abstract To elucidate the physiological adaptation of Escherichia coli due to cra gene knockout, a total of 3,911 gene expressions were investigated by DNA microarray for continuous culture. About 50 genes were differentially regulated for the cra mutant. TCA cycle and glyoxylate shunt were down-regulated, while pentose phosphate (PP) pathway and Entner Doudoroff (ED) pathway were up-regulated in the cra mutant. The glucose uptake rate and the acetate production rate were increased with less acetate consumption for the cra mutant. To identify the genes controlled by Cra protein, the Cra recognition weight matrix from foot-printing data was developed and used to scan the whole genome. Several new Cra-binding sites were found, and some of the result was consistent with the DNA microarray data. The ED pathway was active in the cra mutant; we constructed cra.edd double genes knockout mutant to block this pathway, where the acetate overflowed due to the down-regulation of aceA,B and icd gene expressions. Then we further constructed cra.edd.iclR triple genes knockout mutant to direct the carbon flow through the glyoxylate pathway. The cra.edd.iclR mutant showed the least acetate production, resulting in the highest cell yield together with the activation of the glycolysis pathway, but the glucose consumption rate could not be improved.
    Language English
    Dates of publication 2008-11
    Size p. 559-571.
    Publisher Springer-Verlag
    Publishing place Berlin/Heidelberg
    Document type Article
    ZDB-ID 124824-8
    ISSN 1432-072X ; 0302-8933
    ISSN (online) 1432-072X
    ISSN 0302-8933
    DOI 10.1007/s00203-008-0406-2
    Database NAL-Catalogue (AGRICOLA)

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  6. Article ; Online: Keratinolytic Activity of Some Newly Isolated Bacillus Species

    Md. Mozammel Hoq / Khandaker Al Zaid Siddiquee / Hiroko Kawasaki / Tatsuji Seki

    Journal of Biological Sciences, Vol 5, Iss 2, Pp 193-

    2005  Volume 200

    Abstract: Eight bacillus bacteria newly isolated from the effluents of tannery and poultry farms using a feather enrichment technique were identified on the basis of 16S ribosomal RNA gene sequence analysis, physiological and carbohydrates assimilation tests. Of ... ...

    Abstract Eight bacillus bacteria newly isolated from the effluents of tannery and poultry farms using a feather enrichment technique were identified on the basis of 16S ribosomal RNA gene sequence analysis, physiological and carbohydrates assimilation tests. Of them, 3 isolates were revealed as the strains of Bacillus licheniformis , two as B. cereus group and one each of B. subtilis , B. borstelensis and B. sphericus . Most of them demonstrated significant levels of keratinolytic protease on keratinous substrates (feather meal or hair keratin) in basal medium as a sole source of carbon, nitrogen and sulphur at 37�C and pH 8.0 in shake culture. Supplementation of yeast extract and molasses with feather in the basal medium increased the enzyme activity by most of the bacillus cultures. Commercial feather meal supported higher activity than that of commercial keratin powder. Of the bacillus species, B. subtilis MZK-7 and three strains of B. licheniformis displayed higher levels of keratinolytic activity under comparable conditions. The enzyme activity was found to be a function of cultivation times by different bacillus cultures. B. borstelensis MZK-6 had reached to its maximum activity after 32 h while the others did the same after 48 to 60 h on feather meal. The hydrolysis of synthetic peptides tested suggests that, among others, the enzymes from B. licheniformis strains and B. subtilis MZK-7 possess high levels of chymotripsin like (active towards Suc-Ala-Ala-Ala-pNA) and proteinase-K, elastase and subtilisin like (active towards Suc-Ala-Ala-Pro-Phe-pNA) protease activities. The protease inhibition studies with the enzymes from B. licheniformis strains and B. subtilis MZK-7 demonstrated the enzyme as serine protease while that of from B. borstenlensis MZK-6 and two strains B. cereus group demonstrated the neutral protease. The present results will be a useful basis for future studies on biotechnological production and application of keratinolytic enzymes.
    Keywords Keratinolytic enzymes ; 16S rDNA ; Bacillus licheniformis MZK ; Biology (General) ; QH301-705.5 ; Science ; Q ; DOAJ:Biology ; DOAJ:Biology and Life Sciences
    Subject code 572
    Language English
    Publishing date 2005-01-01T00:00:00Z
    Publisher Asian Network for Scientific Information
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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