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Li SX, Wu HT, Liu YT, Jiang YY, Zhang YS, Liu WD, Zhu KJ, Li DM, Zhang H. The F 1F o-ATP Synthase β Subunit Is Required for Candida albicans Pathogenicity Due to Its Role in Carbon Flexibility. Front Microbiol 2018; 9:1025. [PMID: 29875745 PMCID: PMC5974098 DOI: 10.3389/fmicb.2018.01025] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2017] [Accepted: 05/01/2018] [Indexed: 11/13/2022] Open
Abstract
Previous work has explored link between mitochondrial biology and fungal pathogenicity in F1Fo-ATP synthase in Candida albicans. In this work we have detailed the more specific roles of the F1Fo-ATP synthase β subunit, a key protein subunit of F1Fo-ATP synthase. The ability to assimilate alternative carbons in glucose-limited host niches is known to be a critical factor for infection caused by opportunistic pathogens including C. albicans. The function of the F1Fo-ATP synthase β subunit was characterized through the construction of an ATP2 gene null mutant (atp2Δ/Δ) and the gene-reconstituted strain (atp2Δ/ATP2) in order to understand the link between carbon metabolism and C. albicans pathogenesis. Cell growth, viability, cellular ATP content, mitochondrial membrane potential (ΔΨm), and intracellular ROS were compared between null mutant and control strain. Results showed that growth of the atp2Δ/Δ mutant in synthetic medium was slower than in complex medium. However, the synthetic medium delayed the onset of reduced cell viability and kept cellular ATP content from becoming fully depleted. Consistent with these observations, we identified transcriptional changes in metabolic response that activated other ATP-generating pathways, thereby improving cell viability during the initial phase. Unlike glucose effects, the atp2Δ/Δ mutant exhibited an immediate and sharp reduction in cell viability on non-fermentable carbon sources, consistent with an immediate depletion of cellular ATP content. Along with a reduced viability in non-fermentable carbon sources, the atp2Δ/Δ mutant displayed avirulence in a murine model of disseminated candidiasis as well as lower fungal loads in mouse organs. Regardless of the medium, however, a decrease in mitochondrial membrane potential (ΔΨm) was found in the atp2Δ/Δ mutant but ROS levels remained in the normal range. These results suggest that the F1Fo-ATP synthase β subunit is required for C. albicans pathogenicity and operates by affecting metabolic flexibility in carbon consumption.
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Affiliation(s)
- Shui-Xiu Li
- Department of Dermatology, The First Affiliated Hospital of Jinan University, Guangzhou, China.,Institute of Mycology, Jinan University, Guangzhou, China
| | - Hao-Tian Wu
- Department of Dermatology, The First Affiliated Hospital of Jinan University, Guangzhou, China.,Institute of Mycology, Jinan University, Guangzhou, China
| | - Yu-Ting Liu
- Department of Dermatology, The First Affiliated Hospital of Jinan University, Guangzhou, China.,Institute of Mycology, Jinan University, Guangzhou, China
| | - Yi-Ying Jiang
- Department of Dermatology, The First Affiliated Hospital of Jinan University, Guangzhou, China.,Institute of Mycology, Jinan University, Guangzhou, China
| | - Yi-Shan Zhang
- Department of Dermatology, The First Affiliated Hospital of Jinan University, Guangzhou, China.,Institute of Mycology, Jinan University, Guangzhou, China
| | - Wei-Da Liu
- Jiangsu Key Laboratory of Molecular Biology for Skin Diseases and STIs, Institute of Dermatology, Chinese Academy of Medical Sciences, Nanjing, China
| | - Kun-Ju Zhu
- Department of Dermatology, The First Affiliated Hospital of Jinan University, Guangzhou, China.,Institute of Mycology, Jinan University, Guangzhou, China
| | - Dong-Mei Li
- Department of Microbiology and Immunology, Georgetown University Medical Center, Washington, DC, United States
| | - Hong Zhang
- Department of Dermatology, The First Affiliated Hospital of Jinan University, Guangzhou, China.,Institute of Mycology, Jinan University, Guangzhou, China
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Foy JJ, Bhattacharjee JK. Biosynthesis and regulation of fructose-1,6-bisphosphatase and phosphofructokinase in Saccharomyces cerevisiae grown in the presence of glucose and gluconeogenic carbon sources. J Bacteriol 1978; 136:647-56. [PMID: 213420 PMCID: PMC218590 DOI: 10.1128/jb.136.2.647-656.1978] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The mode of synthesis and the regulation of fructose-1,6-bisphosphatase (Fbpase), a gluconeogenic enzyme, and phosphofructokinase (PFK), a glycolytic enzyme, were investigated in Saccharomyces cerevisiae after growth in the presence of different concentrations of glucose or various gluconeogenic carbon sources. The activity of FBPase appeared in the cells after the complete disappearance of glucose from the growth medium with a concomitant increase of the pH and no significant change in the levels of accumulated ethanol. The appearance of FBPase activity following glucose depletion was dependent upon the synthesis of protein. The FBPase PFK were present in glucose-, ethanol-, glycerol-, lactate-, or pyruvate-grown cells; however, the time of appearance and the levels of both these enzymes varied. The FBPase activity was always higher in 1% glucose-grown cells than in cells grown in the presence of gluconeogenic carbon sources. Phosphoglucose isomerase activity did not vary significantly. Addition of glucose to an FBPase and PFK synthesizing culture resulted in a complete loss, followed by a reappearance, of PFK activity. In the presence of cycloheximide the disappearance of glucose and the changes in the levels of FBPase and PFK were decreased significantly. It is concluded that S. cerevisiae exhibits a more efficient synthesis of FBPase after the exhaustion of glucose compared to the activity present in cells grown in the presence of exogenous gluconeogenic carbon sources. Two metabolically antagonistic enzymes, FBPase and PFK, are present during the transition phase, but not during the exponential phase, of growth, and the decay or inactivation of these enzymes in vivo may be dependent upon a glucose-induced protease activity.
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WU RAY, BAHL CHANDERP, NARANG SARANA. Lactose Operator–Repressor Interaction* *This is paper 8 in our series, "Studies on the Lactose Operon." Paper 7 is Bahl et at. (6). ACTA ACUST UNITED AC 1978. [DOI: 10.1016/b978-0-12-152813-3.50009-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/12/2023]
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4
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Gandhi AP, Kjaergaard L. Effect of carbon dioxide on the formation of alpha-amylase by Bacillus subtilis growing in continuous and batch cultures. Biotechnol Bioeng 1975; 17:1109-18. [PMID: 829576 DOI: 10.1002/bit.260170803] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The influence of CO2 on the information of alpha-amylase by Bacillus subtilis NCIB 8646 growing in continuous and batch cultures was investigated. Different levels of CO2 examined in the batch cultures stimulated the formation of alpha-amylase, with the highest activity being obtained using 6% CO2 (v/v). The additions of CO2 inhibit the growth and division of vegetative cells of B. subtilis when CO2 is present in a concentration of more than 3% (v/v). In chemostat cultures, air containing 8% CO2 (v/v) increased the specific enzyme productivity almost three times over the control, without affecting the cell growth. An attempt is made to correlate the obtained results with the alesis.
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5
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Seto H, Nagata Y, Maruo B. Two types of glucose effects on beta-galactosidase synthesis in a membrane fraction of Escherichia coli: correlation with repression observed in intact cells. J Bacteriol 1975; 122:660-8. [PMID: 165172 PMCID: PMC246104 DOI: 10.1128/jb.122.2.660-668.1975] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
A membrane fraction obtained from an osmotic lysate of Escherichia coli spheroplasts retains capability to synthesize beta-galactosidase. The system also retains cellular regulatory functions, one of which is known as catabolite repression. Two types of repression of beta-galactosidase synthesis were observed in this membrane system: one was caused by the addition of 2-deoxyglucose or glucose at a low concentration (3 times 10- minus 4 M), and the other was caused by glucose-6-phosphate or glucose at a high concentration (3 times 10- minus 2 M). In the presence of cyclic adenosine 3',5'-monophosphate (10 mM), repression caused by the former was completely reversed, whereas repression by the latter was only partially reversed. Conditions in intact cells causing transient and permanent repression were also investigated. Upon addition of 2-deoxyglucose or glucose at a low concentration to intact cells, only transient repression of beta-galactosidase synthesis was observed. Glucose at a high concentration caused both transient and subsequent permanent repression, and intensity of permanent repression depended upon glucose concentration, whereas duration and intensity of transient repression were independent of glucose concentration. Mutants deficient in phosphoenolpyruvate-phosphotransferase system (Hpr minus and enzyme I minus) showed transient repression but failed to show permanent repression. In mutants deficient in glucose catabolism beyond glucose-6-phosphate, both transient and permanent repression were observed. Correlation between the observations in the membrane system and in intact cells is discussed. The results obtained here strongly suggest that transient repression is caused by glucose itself, and that permanent repression is caused by glucose-6-phosphate of high intracellular levels of glucose.
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Abstract
Several factors which regulate the synthesis of enterotoxin B were examined in Staphylococcus aureus S-6 and in its heme-requiring mutant S-6H2. The kinetics of enterotoxin B synthesis during anaerobic growth were identical to those observed under aerobic conditions; extracellular enterotoxin accumulated in the medium during the transition between exponential and stationary phase growth. Strain S-6H2 lacked a functional electron transport system unless the medium was supplemented with heme. In a casein hydrolysate medium, the presence or absence of a functional electron transport system had no effect upon the differential rate of toxin synthesis. The repression of toxin synthesis by glucose at either pH 6.0 or 7.7 or by pyruvate at pH 7.7 occurred in the absence of a functional electron transport system, but was enhanced significantly in its presence. Thus, a functional electron transport system appears to be involved in regulating the degree of glucose and pyruvate repression of enterotoxin B synthesis.
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Moses V, Sharp PB. The influence of recent growth history on the phenotype of Escherichia coli. Folia Microbiol (Praha) 1972; 17:1-16. [PMID: 4551443 DOI: 10.1007/bf02872248] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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8
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Sullivan RA, Infantino DG. Carbohydrate Metabolism in Cheese. II. Coenzymes, 2-Deoxy-D-Ribose, and 2-Deoxy-D-Ribose-5-Phosphate. J Dairy Sci 1972. [DOI: 10.3168/jds.s0022-0302(72)85422-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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9
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Görts CP. Some aspects of catabolite repression of mitochondrial enzymes in Saccharomyces cerevisiae. Antonie Van Leeuwenhoek 1971; 37:161-9. [PMID: 5314549 DOI: 10.1007/bf02218477] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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10
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The Lac Repressor. ACTA ACUST UNITED AC 1971. [DOI: 10.1016/b978-0-12-152804-1.50008-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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11
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Chapter V Methods for Studying Enzyme Regulation. METHODS IN MICROBIOLOGY 1971. [DOI: 10.1016/s0580-9517(08)70577-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register]
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12
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Riggs AD, Newby RF, Bourgeois S. lac repressor--operator interaction. II. Effect of galactosides and other ligands. J Mol Biol 1970; 51:303-14. [PMID: 4320936 DOI: 10.1016/0022-2836(70)90144-0] [Citation(s) in RCA: 159] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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13
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Moses V, Sharp PB. Interactions between metabolic intermediates and beta-galactosidase from Escherichia coli. Biochem J 1970; 118:491-5. [PMID: 4319544 PMCID: PMC1179217 DOI: 10.1042/bj1180491] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
1. 5-Phosphorylribose 1-pyrophosphate, in the presence of beta-mercaptoethanol, protected beta-galactosidase from heat inactivation. Many other substances, including 3':5'-cyclic-AMP, were without effect. 2. The efficiency of complementation in vitro of beta-galactosidase segments was decreased by 5-phosphorylribose 1-pyrophosphate but not by 3':5'-cyclic-AMP. Neither substance affected the activity of the complete enzyme. 3. Some indications as to the possible identity of the catabolite repression effector are presented.
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Moses V, Sharp PB. Adenosine 3':5'-cyclic monophosphate and catabolite repression in Escherichia coli. Biochem J 1970; 118:481-9. [PMID: 4319543 PMCID: PMC1179216 DOI: 10.1042/bj1180481] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
1. Both permanent and transient catabolite repression of beta-galactosidase synthesis in Escherichia coli are abolished by 5mm-3':5'-cyclic-AMP when elicited by glucose, but not when caused by a mixture of glucose, glucose 6-phosphate, gluconate and casein hydrolysate (casamino acids). 2. Glucose uptake is slightly increased by 3':5'-cyclic-AMP. 3. No significant effects of the nucleotide were found on the synthesis of protein and RNA, either in exponential growth on one substrate, or during a growth shift from glycerol to glycerol plus glucose. 4. Marked changes in the soluble-protein profiles of cells growing in glycerol and glucose were caused by the presence of 3':5'-cyclic-AMP. 5. Measurements of (14)CO(2) release from specifically-labelled glucose showed that 3':5'-cyclic-AMP greatly stimulated glycolytic activity while having a minor depressing effect on the metabolic flow through the pentose phosphate cycle. 6. The concentrations of several metabolic intermediates, particularly fructose 1,6-diphosphate, were greatly affected by the presence of 3':5'-cyclic-AMP. 7. Several metabolites partially relieved glucose repression of beta-galactosidase synthesis in EDTA-treated cells; three out of five of these metabolites reversed the effect more effectively than did 3':5'-cyclic-AMP. 8. The evidence for and against a direct role for 3':5'-cyclic-AMP is discussed. It is concluded that the evidence for indirect action is at least as strong as that for direct action.
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15
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Tyler B, Magasanik B. Physiological basis of transient repression of catabolic enzymes in Escherichia coli. J Bacteriol 1970; 102:411-22. [PMID: 4911541 PMCID: PMC247566 DOI: 10.1128/jb.102.2.411-422.1970] [Citation(s) in RCA: 37] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Transient repression of catabolic enzymes occurs in cells that encounter a new carbon compound in their growth medium, but only when the cells contain the enzyme catalyzing the transfer of phosphate from phosphoenolpyruvate to a small heat-stable protein (HPr), as well as a permease capable of transporting the new compound across the cell membrane. The newly added compound need not be metabolized. The degree and duration of the transient repression have no obvious relation to the intracellular level of the exogenously added compound. It is suggested that the actual passage of the compound through the cell membrane is responsible for the repression.
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17
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Regulation of Inducible Enzyme Synthesis in Escherichia coli by Cyclic Adenosine 3',5'-Monophosphate. J Biol Chem 1969. [DOI: 10.1016/s0021-9258(18)63549-5] [Citation(s) in RCA: 118] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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18
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Janecek J, Rickenberg HV. The kinetics of catabolite repression in Escherichia coli. Folia Microbiol (Praha) 1969; 14:285-90. [PMID: 4897960 DOI: 10.1007/bf02872693] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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19
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20
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Hsie AW, Rickenberg HV, Schulz DW, Kirsch WM. Steady-state concentrations of glucose-6-phosphate, 6-phosphogluconate, and reduced nicotinamide adenine dinucleotide phosphate in strains of Escherichia coli sensitive and resistant to catabolite repression. J Bacteriol 1969; 98:1407-8. [PMID: 4389233 PMCID: PMC315342 DOI: 10.1128/jb.98.3.1407-1408.1969] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
No correlation was found between the cellular steady-state concentrations of glucose-6-phosphate, 6-phosphogluconate, and reduced nicotinamide dinucleotide phosphate and resistance versus sensitivity to catabolite repression.
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21
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Dobrogosz WJ. Corepressor system for catabolite repression of the lac operon in Escherichia coli. J Bacteriol 1969; 97:1083-92. [PMID: 4887497 PMCID: PMC249818 DOI: 10.1128/jb.97.3.1083-1092.1969] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Acetylated amino sugars, normally used in the biosynthesis of cell walls and cell membranes, were found to play a role as corepressors for catabolite repression of the lac operon in Escherichia coli. This conclusion was derived from studies conducted on mutants of E. coli that were able to assimilate an exogenous source of N-acetylglucosamine (AcGN) but were unable to dissimilate or grow on this compound. At concentrations less than 10(-4)m, AcGN caused severe catabolite repression of beta-galactosidase synthesis in cultures grown under either nonrepressed or partially repressed conditions. This repression occurred in the absence of any effect of AcGN on either the carbon and energy metabolism or the growth of the organism. In addition, this repression by AcGN occurred in a mutant strain that is constitutive for beta-galactosidase production, demonstrating that the AcGN effect does not involve the uptake of inducer. This model for the corepressor system of catabolite repression is discussed in relation to the existing theories on repression of the lac operon.
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22
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Silver RS, Mateles RI. Control of mixed-substrate utilization in continuous cultures of Escherichia coli. J Bacteriol 1969; 97:535-43. [PMID: 4886282 PMCID: PMC249724 DOI: 10.1128/jb.97.2.535-543.1969] [Citation(s) in RCA: 56] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
The chemostat culture technique was used to study the control mechanisms which operate during utilization of mixtures of glucose and lactose and glucose and l-aspartic acid by populations of Escherichia coli B6. Constitutive mutants were rapidly selected during continuous culture on a mixture of glucose and lactose, and the beta-galactosidase level of the culture increased greatly. After mutant selection, the specific beta-galactosidase level of the culture was a decreasing function of growth rate. In cultures of both the inducible wild type and the constitutive mutant, glucose and lactose were simultaneously utilized at moderate growth rates, whereas only glucose was used in the inducible cultures at high growth rates. Catabolite repression was shown to be the primary mechanism of control of beta-galactosidase level and lactose utilization in continuous culture on mixed substrates. In batch culture, as in the chemostat, catabolite repression acting by itself on the lac enzymes was insufficient to prevent lactose utilization or cause diauxie. Interference with induction of the lac operon, as well as catabolite repression, was necessary to produce diauxic growth. Continuous cultures fed mixtures of glucose and l-aspartic acid utilized both substrates at moderate growth rates, even though the catabolic enzyme aspartase was linearly repressed with increasing growth rate. Although the repression of aspartase paralleled the catabolite repression of beta-galactosidase, l-aspartic acid could be utilized even at very low levels of the catabolic enzyme because of direct anabolic incorporation into protein.
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23
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Tyler B, Magasanik B. Molecular basis of transient repression of beta-galactosidase in Escherichia coli. J Bacteriol 1969; 97:550-6. [PMID: 4886283 PMCID: PMC249726 DOI: 10.1128/jb.97.2.550-556.1969] [Citation(s) in RCA: 32] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
The molecular basis of transient repression of beta-galactosidase by glucose was examined. This repression acted only at the level of transcription. Apparently, it was not mediated by the I-gene product. Analysis of single cells in a culture subjected to transient repression showed that essentially all cells initially experienced repression and later became gradually resistant to repression.
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24
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Paigen K, Williams B. Catabolite Repression and other Control Mechanisms in Carbohydrate Utilization. Adv Microb Physiol 1969. [DOI: 10.1016/s0065-2911(08)60444-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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25
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Beck C, von Meyenburg HK. Enzyme pattern and aerobic growth of Saccharomyces cerevisiae under various degrees of glucose limitation. J Bacteriol 1968; 96:479-86. [PMID: 4386290 PMCID: PMC252321 DOI: 10.1128/jb.96.2.479-486.1968] [Citation(s) in RCA: 153] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
The enzyme pattern of Saccharomyces cerevisiae was followed during batch growth and in continuous culture in a synthetic medium limited for glucose under aerobic conditions. Seven enzymes were measured: succinate-cytochrome c oxidoreductase, malate dehydrogenase, nicotinamide adenine dinucleotide-linked glutamate dehydrogenase, malate synthase, isocitrate lyase, aldolase, and nicotinamide adenine dinucleotide phosphate (NADP(+))-linked glutamate dehydrogenase. During fermentation of glucose and high growth rate (mu) during the first log phase in batch experiments, the first five enzymes (group I) were repressed, and aldolase and NADP(+)-linked glutamate dehydrogenase (group II) were derepressed. During growth on the accumulated ethyl alcohol and lower mu, the group I enzymes were preferentially formed and the other two were repressed. A sequence of derepression of the group I enzymes was found during the shift from glucose to ethyl alcohol metabolism, which can be correlated with a strong increase in the percentage of single (nonbudding) cells in the population. A correlation between the state of cells in the budding cycle and enzyme repression and derepression is suggested. In continuous culture, the enzyme pattern was shown to be related to the growth rate. The group I enzymes were repressed at high growth rates, while the group II enzymes were derepressed. Each enzyme exhibits a different dependence. The enzyme pattern is shown to depend on the rate of substrate consumption as well as on the type of metabolism and to be correlated with the budding cycle. The enzyme pattern is considered to be controlled by changes of intracellular catabolic or metabolic conditions inherent in the division cycle.
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Leitzmann C, Bernlohr RW. Threonine dehydratase of Bacillus licheniformis. II. Regulation during development. BIOCHIMICA ET BIOPHYSICA ACTA 1968; 151:461-72. [PMID: 5688827 DOI: 10.1016/0005-2744(68)90114-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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27
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Abstract
N-acetylglucosamine was found to be a good repressor source for catabolite repression of the beta-galactosidase system in Escherichia coli. It was found capable of increasing the severity of repression by glucose or gluconate when included in the medium with either of these substrates. N-acetylglucosamine was shown to be assimilated under these conditions, but had no effect on culture growth rates. Its influence on catabolite repression was not altered by growth in the presence of inhibiting levels of penicillin. These findings indicated that catabolite repression may be associated with certain reactions of amino sugar metabolism. A working model has been formulated along these lines and will be used to explore this possible relationship further.
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28
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Blackkolb F, Schlegel HG. Katabolische Repression und Enzymhemmung durch molekularen Wasserstoff bei Hydrogenomonas. Arch Microbiol 1968. [DOI: 10.1007/bf00410399] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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29
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Abstract
Severe transient repression of constitutive or induced beta-galactosidase synthesis occurs upon the addition of glucose to cells of Escherichia coli growing on glycerol, succinic acid, or lactic acid. Only mutants particularily well adapted to growth on glucose exhibit this phenomenon when transferred to a glucose-containing medium. No change in ribonucleic acid (RNA) metabolism was observed during transient repression. We could show that transient repression is pleiotropic, affecting all products of the lac operon. It occurs in a mutant insensitive to catabolite repression. It is established much more rapidly than catabolite repression, and is elicited by glucose analogues that are phosphorylated but not further catabolized by the cell. Thus, transient repression is not a consequence of the exclusion of inducer from the cell, does not require catabolism of the added compound, and does not involve a gross change in RNA metabolism. We conclude that transient repression is distinct from catabolite repression.
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30
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Hsie AW, Rickenberg HV. Catabolite repression in Escherichia coli: the role of glucose 6-phosphate. Biochem Biophys Res Commun 1967; 29:303-10. [PMID: 4864799 DOI: 10.1016/0006-291x(67)90453-6] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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31
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Palmer J, Moses V. Involvement of the lac regulatory genes in catabolite repression in Escherichia coli. Biochem J 1967; 103:358-66. [PMID: 5340365 PMCID: PMC1270416 DOI: 10.1042/bj1030358] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
1. Acute transient catabolite repression of beta-galactosidase synthesis, observed when glucose is added to glycerol-grown cells of Escherichia coli (Moses & Prevost, 1966), requires the presence of a functional operator gene (o) in the lactose operon. Total deletion of the operator gene abolished acute transient repression, even in the presence of a functional regulator gene (i). 2. Regulator constitutives (i(-)) also show transient repression provided that the operator gene is functional. Regulator deletion mutants (i(del)), with which to test specifically the role of the i gene, have not so far been available. 3. The above mutants, showing various changes in the lactose operon, show no alteration in the effect of glucose on induced tryptophanase synthesis. Glucose metabolism, as measured in terms of the release of (14)CO(2) from [1-(14)C]glucose and [6-(14)C]glucose, also showed no differences between strains exhibiting or not exhibiting transient repression. This suggests no change in the operation of the pentose phosphate cycle, a metabolic activity known to be of paramount importance for glucose repression of beta-galactosidase synthesis (Prevost & Moses, 1967). 4. Chronic permanent repression by glucose of beta-galactosidase synthesis (less severe in degree than acute transient repression) persists in strains in which transient repression has been genetically abolished. Constitutive alkaline-phosphatase synthesis, which shows no transient repression, also demonstrates chronic permanent repression by glucose. 5. Chloramphenicol repression also persists in mutants with no transient repression, and also affects alkaline phosphatase. It is suggested that chronic permanent repression and chloramphenicol repression are non-specific, and that they do not influence beta-galactosidase synthesis via the regulatory system of the lactose operon.
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