scholarly journals The β-ketoadipate pathway of Acinetobacter baylyi undergoes carbon catabolite repression, cross-regulation and vertical regulation, and is affected by Crc

Microbiology ◽  
2010 ◽  
Vol 156 (5) ◽  
pp. 1313-1322 ◽  
Author(s):  
Fenja S. Bleichrodt ◽  
Rita Fischer ◽  
Ulrike C. Gerischer
Keyword(s):  
Aromatic Compounds ◽  
Transcriptional Repression ◽  
Catabolite Repression ◽  
Carbon Catabolite Repression ◽  
Gene Cassette ◽  
Luciferase Reporter ◽  
Transcriptional Level ◽  
Luciferase Reporter Gene ◽  
Acinetobacter Baylyi ◽  
Benzyl Esters

The degradation of many structurally diverse aromatic compounds in Acinetobacter baylyi is accomplished by the β-ketoadipate pathway. In addition to specific induction of expression by certain aromatic compounds, this pathway is regulated by complex mechanisms at multiple levels, which are the topic of this study. Multiple operons feeding into the β-ketoadipate pathway are controlled by carbon catabolite repression (CCR) caused by succinate plus acetate. The pathways under study enable the catabolism of benzoate (ben), catechol (catA), cis,cis-muconate (catB,C,I,J,F,D), vanillate (van), hydroxycinnamates (hca), dicarboxylates (dca), salicylate (sal), anthranilate (ant) and benzyl esters (are). For analysis of CCR at the transcriptional level a luciferase reporter gene cassette was introduced into the operons. The Crc (catabolite repression control) protein is involved in repression of all operons (except for catA), as demonstrated by the analysis of respective crc strains. In addition, cross-regulation was demonstrated for the vanA,B, hca and dca operons. The presence of protocatechuate caused transcriptional repression of the vanA,B- and hca-encoded funnelling pathways (vertical regulation). Thus the results presented extend the understanding both of CCR and of the effects of Crc for all aromatic degradative pathways of A. baylyi and increase the number of operons known to be controlled by two additional mechanisms, cross-regulation and vertical regulation.

scholarly journals Intracellular 2-keto-3-deoxy-6-phosphogluconate is the signal for carbon catabolite repression of phenylacetic acid metabolism in Pseudomonas putida KT2440

Microbiology ◽  
2009 ◽  
Vol 155 (7) ◽  
pp. 2420-2428 ◽  
Author(s):  
Juhyun Kim ◽  
Jinki Yeom ◽  
Che Ok Jeon ◽  
Woojun Park
Keyword(s):  
Pseudomonas Putida ◽  
Transcriptional Repression ◽  
Catabolite Repression ◽  
Phenylacetic Acid ◽  
Carbon Catabolite Repression ◽  
Transcriptional Level ◽  
Pseudomonas Putida Kt2440 ◽  
Coa Ligase ◽  
Additional Support

The growth pattern of Pseudomonas putida KT2440 in the presence of glucose and phenylacetic acid (PAA), where the sugar is used in preference to the aromatic compound, suggests that there is carbon catabolite repression (CCR) of PAA metabolism by glucose or gluconate. Furthermore, CCR is regulated at the transcriptional level. However, this CCR phenomenon does not occur in PAA-amended minimal medium containing fructose, pyruvate or succinate. We previously identified 2-keto-3-deoxy-6-phosphogluconate (KDPG) as an inducer of glucose metabolism, and this has led to this investigation into the role of KDPG as a signal compound for CCR. Two mutant strains, the edd mutant (non-KDPG producer) and the eda mutant (KDPG overproducer), grew in the presence of PAA but not in the presence of glucose. The edd mutant utilized PAA even in the presence of glucose, indicating that CCR had been abolished. This observation has additional support from the finding that there is high phenylacetyl-CoA ligase activity in the edd mutant, even in the presence of glucose+PAA, but not in wild-type cells under the same conditions. Unlike the edd mutant, the eda mutant did not grow in the presence of glucose+PAA. Interestingly, there was no uptake and/or metabolism of PAA in the eda mutant cells under the same conditions. Targeted disruption of PaaX, a repressor of the PAA operon, had no effect on CCR of PAA metabolism in the presence of glucose, suggesting that there is another transcriptional repression system associated with the KDPG signal. This is the first study to demonstrate that KDPG is the true CCR signal of PAA metabolism in P. putida KT2440.

scholarly journals A Novel Redox-Sensing Histidine Kinase That Controls Carbon Catabolite Repression inAzoarcussp. CIB

mBio ◽  
2019 ◽  
Vol 10 (2) ◽  
Author(s):  
J. Andrés Valderrama ◽  
Helena Gómez-Álvarez ◽  
Zaira Martín-Moldes ◽  
M. Álvaro Berbís ◽  
F. Javier Cañada ◽  
...  
Keyword(s):  
Aromatic Compounds ◽  
Histidine Kinase ◽  
Catabolite Repression ◽  
Carbon Catabolite Repression ◽  
Response Regulator ◽  
Sensor Kinase ◽  
General Role ◽  
Two Component ◽  
Redox Switch ◽  
Redox Sensing

ABSTRACTWe have identified and characterized the AccS multidomain sensor kinase that mediates the activation of the AccR master regulator involved in carbon catabolite repression (CCR) of the anaerobic catabolism of aromatic compounds inAzoarcussp. CIB. A truncated AccS protein that contains only the soluble C-terminal autokinase module (AccS′) accounts for the succinate-dependent CCR control. In vitroassays with purified AccS′ revealed its autophosphorylation, phosphotransfer from AccS′∼P to the Asp60 residue of AccR, and the phosphatase activity toward its phosphorylated response regulator, indicating that the equilibrium between the kinase and phosphatase activities of AccS′ may control the phosphorylation state of the AccR transcriptional regulator. Oxidized quinones, e.g., ubiquinone 0 and menadione, switched the AccS′ autokinase activity off, and three conserved Cys residues, which are not essential for catalysis, are involved in such inhibition. Thiol oxidation by quinones caused a change in the oligomeric state of the AccS′ dimer resulting in the formation of an inactive monomer. This thiol-based redox switch is tuned by the cellular energy state, which can change depending on the carbon source that the cells are using. This work expands the functional diversity of redox-sensitive sensor kinases, showing that they can control new bacterial processes such as CCR of the anaerobic catabolism of aromatic compounds. The AccSR two-component system is conserved in the genomes of some betaproteobacteria, where it might play a more general role in controlling the global metabolic state according to carbon availability.IMPORTANCETwo-component signal transduction systems comprise a sensor histidine kinase and its cognate response regulator, and some have evolved to sense and convert redox signals into regulatory outputs that allow bacteria to adapt to the altered redox environment. The work presented here expands knowledge of the functional diversity of redox-sensing kinases to control carbon catabolite repression (CCR), a phenomenon that allows the selective assimilation of a preferred compound among a mixture of several carbon sources. The newly characterized AccS sensor kinase is responsible for the phosphorylation and activation of the AccR master regulator involved in CCR of the anaerobic degradation of aromatic compounds in the betaproteobacteriumAzoarcussp. CIB. AccS seems to have a thiol-based redox switch that is modulated by the redox state of the quinone pool. The AccSR system is conserved in several betaproteobacteria, where it might play a more general role controlling their global metabolic state.

scholarly journals Cyclin A expression is under negative transcriptional control during the cell cycle.

1996 ◽  
Vol 16 (7) ◽  
pp. 3789-3798 ◽  
Author(s):  
X Huet ◽  
J Rech ◽  
A Plet ◽  
A Vié ◽  
J M Blanchard
Keyword(s):  
Cell Cycle ◽  
Transcriptional Repression ◽  
Transcriptional Control ◽  
Cell Cycle Progression ◽  
Cyclin A ◽  
Luciferase Reporter ◽  
Luciferase Reporter Gene ◽  
Proliferating Cells

Transcription of the gene coding for cyclin A, a protein required for S-phase transit, is cell cycle regulated and is restricted to proliferating cells. To further explore transcriptional regulation linked to cell division cycle control, a genomic clone containing 5' flanking sequences of the murine cyclin A gene was isolated. When it was fused to a luciferase reporter gene, it was shown to function as a proliferation-regulated promoter in NIH 3T3 cells. Transcription of the mouse cyclin A gene is negatively regulated by arrest of cell proliferation. A mutation of a GC-rich sequence conserved between mice and humans is sufficient to relieve transcriptional repression, resulting in a promoter with constitutively high activity. In agreement with this result, in vivo footprinting reveals a protection of the cell cycle-responsive element in G0/early G1 cells which is not observed at later stages of the cell cycle. Moreover, the footprint is present in dimethyl sulfoxide-induced differentiating and not in proliferating Friend erythroleukemia cells. Conversely, two other sites, which in vitro bind ATF-1 and NF-Y, respectively, are constitutively occupied throughout cell cycle progression.

scholarly journals CCAAT Displacement Protein (CDP/cut) Recognizes a Silencer Element Within the Lactoferrin Gene Promoter

Blood ◽  
1997 ◽  
Vol 90 (7) ◽  
pp. 2784-2795 ◽  
Author(s):  
Arati Khanna-Gupta ◽  
Theresa Zibello ◽  
Sarah Kolla ◽  
Ellis J. Neufeld ◽  
Nancy Berliner
Keyword(s):  
Luciferase Activity ◽  
Gene Promoter ◽  
Luciferase Reporter ◽  
Transcriptional Level ◽  
Luciferase Reporter Gene ◽  
Mobility Shift ◽  
Ccaat Displacement Protein ◽  
Lactoferrin Gene ◽  
Mobility Shift Assay ◽  
Silencer Element

Abstract Expression of neutrophil secondary granule protein (SGP) genes is coordinately regulated at the transcriptional level, and is disrupted in specific granule deficiency and leukemia. We analyzed the regulation of SGP gene expression by luciferase reporter gene assays using the lactoferrin (LF) promoter. Reporter plasmids were transiently transfected into non–LF-expressing hematopoietic cell lines. Luciferase activity was detected from reporter plasmids containing basepair (bp) −387 to bp −726 of the LF promoter, but not in a −916-bp plasmid. Transfection of a −916-bp plasmid into a LF-expressing cell line resulted in abrogation of the silencing effect. Sequence analysis of this region revealed three eight-bp repetitive elements, the deletion of which restored wild-type levels of luciferase activity to the −916-bp reporter plasmid. Electrophoretic mobility shift assay and UV cross-linking analysis identified a protein of approximately 180 kD that binds to this region in non–LF-expressing cells but not in LF-expressing cells. This protein was identified to be the CCAAT displacement protein (CDP/cut). CDP/cut has been shown to downregulate expression of gp91-phox, a gene expressed relatively early in the myeloid lineage. Our observations suggest that the binding of CDP/cut to the LF silencer element serves to suppress basal promoter activity of the LF gene in non–LF-expressing cells. Furthermore, overexpression of CDP/cut in cultured myeloid stem cells blocks LF expression upon granulocyte colony-stimulating factor–induced neutrophil maturation without blocking phenotypic maturation. This block in LF expression may be due, in part, to the persistence of CDP/cut binding to the LF silencer element.

scholarly journals An ERG (ets-related gene)-associated histone methyltransferase interacts with histone deacetylases 1/2 and transcription co-repressors mSin3A/B

2003 ◽  
Vol 369 (3) ◽  
pp. 651-657 ◽  
Author(s):  
Liu YANG ◽  
Qi MEI ◽  
Anna ZIELINSKA-KWIATKOWSKA ◽  
Yoshito MATSUI ◽  
Michael L. BLACKBURN ◽  
...  
Keyword(s):  
Transcriptional Repression ◽  
Histone Deacetylases ◽  
Trichostatin A ◽  
Histone Methyltransferase ◽  
Luciferase Reporter ◽  
Related Gene ◽  
Luciferase Reporter Gene ◽  
Histone Tails ◽  
Histone Deacetylase 1 ◽  
Covalent Modifications

Covalent modifications of histone tails play important roles in gene transcription and silencing. We recently identified an ERG (ets-related gene)-associated protein with a SET (suppressor of variegation, enhancer of zest and trithorax) domain (ESET) that was found to have the activity of a histone H3-specific methyltransferase. In the present study, we investigated the interaction of ESET with other chromatin remodelling factors. We show that ESET histone methyltransferase associates with histone deacetylase 1 (HDAC1) and HDAC2, and that ESET also interacts with the transcription co-repressors mSin3A and mSin3B. Deletion analysis of ESET reveals that an N-terminal region containing a tudor domain is responsible for interaction with mSin3A/B and association with HDAC1/2, and that truncation of ESET enhances its binding to mSin3. When bound to a promoter, ESET represses the transcription of a downstream luciferase reporter gene. This repression by ESET is independent of its histone methyltransferase activity, but correlates with its binding to the mSin3 co-repressors. In addition, the repression can be partially reversed by treatment with the HDAC inhibitor trichostatin A. Taken together, these data suggest that ESET histone methyltransferase can form a large, multi-protein complex(es) with mSin3A/B co-repressors and HDAC1/2 that participates in multiple pathways of transcriptional repression.

scholarly journals Gonadotropin-Releasing Hormone-Mediated Phosphorylation of Estrogen Receptor-α Contributes to fosB Expression in Mouse Gonadotrophs

Endocrinology ◽  
2009 ◽  
Vol 150 (10) ◽  
pp. 4583-4593 ◽  
Author(s):  
Junling Chen ◽  
Beum-Soo An ◽  
Linan Cheng ◽  
Geoffrey L. Hammond ◽  
Peter C. K. Leung
Keyword(s):  
Transcriptional Activation ◽  
Early Response ◽  
Estrogen Receptor Α ◽  
Camp Response Element Binding ◽  
Luciferase Reporter ◽  
Transcriptional Level ◽  
Type I ◽  
Pituitary Cells ◽  
Luciferase Reporter Gene ◽  
Response Element

Abstract Estrogen receptors (ERs) are activated by their ligands as well as signaling pathways that alter ER phosphorylation in response to peptide hormones and growth factors. In pituitary gonadotrophs, GnRHs act via the type I GnRH receptor (GnRHR). Both GnRH subtypes (GnRH-I and -II) activate an estrogen response element (ERE)-driven luciferase reporter gene in LβT2 mouse pituitary cells, and GnRH-I is most potent in this regard. Moreover, antide (a GnRH antagonist) and a GnRHR small interfering RNA (siRNA) abrogate this effect, whereas an ERα antagonist (ICI 182,780) does not. The ERα in LβT2 cells is phosphorylated at Ser118 in the nucleus and at Ser167 in both nucleus and cytoplasm after GnRH treatments and coincided with increased ERα binding to its coactivator, the p300/cAMP response element-binding protein-associated factor (PCAF). Moreover, siRNA-mediated knockdown of PCAF levels attenuated GnRH-induced ERE-luciferase transactivation in these cells. Most importantly, both GnRH subtypes robustly up-regulated expression of the immediate early response gene, fosB, whereas cotreatment with ERα siRNA or PCAF siRNA attenuated this effect. This appears to occur at the transcriptional level because corecruitment of ERα and PCAF to an ERE within the endogenous fosB promoter was increased by GnRH treatments, as shown by chromatin immunoprecipitation assays. These data demonstrate that GnRH-mediated phosphorylation of ERα in mouse LβT2 pituitary cells results in its rapid association with PCAF and the transcriptional activation of fosB, and we demonstrate that this in turn likely activates other genes in pituitary cells including the FSH β-subunit gene.

scholarly journals Aromatic degradative pathways in Acinetobacter baylyi underlie carbon catabolite repression

Microbiology ◽  
2008 ◽  
Vol 154 (10) ◽  
pp. 3095-3103 ◽  
Author(s):  
Rita Fischer ◽  
Fenja S. Bleichrodt ◽  
Ulrike C. Gerischer
Keyword(s):  
Catabolite Repression ◽  
Carbon Catabolite Repression ◽  
Acinetobacter Baylyi

scholarly journals CCAAT Displacement Protein (CDP/cut) Recognizes a Silencer Element Within the Lactoferrin Gene Promoter

Blood ◽  
1997 ◽  
Vol 90 (7) ◽  
pp. 2784-2795 ◽  
Author(s):  
Arati Khanna-Gupta ◽  
Theresa Zibello ◽  
Sarah Kolla ◽  
Ellis J. Neufeld ◽  
Nancy Berliner
Keyword(s):  
Luciferase Activity ◽  
Gene Promoter ◽  
Luciferase Reporter ◽  
Transcriptional Level ◽  
Luciferase Reporter Gene ◽  
Mobility Shift ◽  
Ccaat Displacement Protein ◽  
Lactoferrin Gene ◽  
Mobility Shift Assay ◽  
Silencer Element

Expression of neutrophil secondary granule protein (SGP) genes is coordinately regulated at the transcriptional level, and is disrupted in specific granule deficiency and leukemia. We analyzed the regulation of SGP gene expression by luciferase reporter gene assays using the lactoferrin (LF) promoter. Reporter plasmids were transiently transfected into non–LF-expressing hematopoietic cell lines. Luciferase activity was detected from reporter plasmids containing basepair (bp) −387 to bp −726 of the LF promoter, but not in a −916-bp plasmid. Transfection of a −916-bp plasmid into a LF-expressing cell line resulted in abrogation of the silencing effect. Sequence analysis of this region revealed three eight-bp repetitive elements, the deletion of which restored wild-type levels of luciferase activity to the −916-bp reporter plasmid. Electrophoretic mobility shift assay and UV cross-linking analysis identified a protein of approximately 180 kD that binds to this region in non–LF-expressing cells but not in LF-expressing cells. This protein was identified to be the CCAAT displacement protein (CDP/cut). CDP/cut has been shown to downregulate expression of gp91-phox, a gene expressed relatively early in the myeloid lineage. Our observations suggest that the binding of CDP/cut to the LF silencer element serves to suppress basal promoter activity of the LF gene in non–LF-expressing cells. Furthermore, overexpression of CDP/cut in cultured myeloid stem cells blocks LF expression upon granulocyte colony-stimulating factor–induced neutrophil maturation without blocking phenotypic maturation. This block in LF expression may be due, in part, to the persistence of CDP/cut binding to the LF silencer element.

scholarly journals Carbon catabolite repression involves physical interaction of the transcription factor CRE1/CreA and the Tup1–Cyc8 complex in Penicillium oxalicum and Trichoderma reesei

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Yueyan Hu ◽  
Mengxue Li ◽  
Zhongjiao Liu ◽  
Xin Song ◽  
Yinbo Qu ◽  
...  
Keyword(s):  
Gene Expression ◽  
Filamentous Fungi ◽  
Transcriptional Repression ◽  
Catabolite Repression ◽  
Enzyme Production ◽  
Carbon Catabolite Repression ◽  
Penicillium Oxalicum ◽  
Physical Interaction ◽  
Corepressor Complex ◽  
Encoding Gene

Abstract Background Cellulolytic enzyme production in filamentous fungi requires a release from carbon catabolite repression (CCR). The protein CRE1/CreA (CRE = catabolite responsive element) is a key transcription factor (TF) that is involved in CCR and represses cellulolytic gene expression. CRE1/CreA represents the functional equivalent of Mig1p, an important Saccharomyces cerevisiae TF in CCR that exerts its repressive effect by recruiting a corepressor complex Tup1p–Cyc8p. Although it is known from S. cerevisiae that CRE1/CreA might repress gene expression via interacting with the corepressor complex Tup1–Cyc8, this mechanism is unconfirmed in other filamentous fungi, since the physical interaction has not yet been verified in these organisms. The precise mechanism on how CRE1/CreA achieves transcriptional repression after DNA binding remains unknown. Results The results from tandem affinity purification and bimolecular fluorescence complementation revealed a direct physical interaction between the TF CRE1/CreA and the complex Tup1–Cyc8 in the nucleus of cellulolytic fungus Trichoderma reesei and Penicillium oxalicum. Both fungi have the ability to secrete a complex arsenal of enzymes to synergistically degrade lignocellulosic materials. In P. oxalicum, the protein PoCyc8, a subunit of complex Tup1–Cyc8, interacts directly with TF PoCreA and histone H3 lysine 36 (H3K36) methyltransferase PoSet2 in the nucleus. The di-methylation level of H3K36 in the promoter of prominent cellulolytic genes (cellobiohydrolase-encoding gene Pocbh1/cel7A and endoglucanase-encoding gene Poegl1/cel7B) is positively correlated with the expression levels of TF PoCreA. Since the methylation of H3K36 was also demonstrated to be a repression marker of cellulolytic gene expression, it appears feasible that the cellulolytic genes are repressed via PoCreA-Tup1–Cyc8-Set2-mediated transcriptional repression. Conclusion This study verifies the long-standing conjecture that the TF CRE1/CreA represses gene expression by interacting with the corepressor complex Tup1–Cyc8 in filamentous fungi. A reasonable explanation is proposed that PoCreA represses gene expression by recruiting complex PoTup1–Cyc8. Histone methyltransferase Set2, which methylates H3K36, is also involved in the regulatory network by interacting with PoCyc8. The findings contribute to the understanding of CCR mechanism in filamentous fungi and could aid in biotechnologically relevant enzyme production.

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