Catabolite-Like Repression of Extracellular Enzyme Production in Vibrio parahaemolyticus

Production of extracellular amylase and protease in Vibrio parahaemolyticus was repressed by various carbohydrates present in the medium. In addition, the protease production was repressed very strongly by peptones or casamino acids. Cyclic adenosine 3′, 5′-monophosphate (cyclic AMP) added exogenously could reverse the repression of amylase production, but not that of protease production irrespective of the “repressors” used. Mutants of V. parahaemolyticus, which resembled the reported cya (adenylate cyclase) and crp (cyclic AMP receptor protein) mutants of Escherichia coli and related organisms, were examined for the exoenzyme production. Amylase production in the mutants was defective, while their protease production was not defective, but rather accentuated as compared with that in the parental strain. These findings strongly suggest that amylase production is subject to catabolite repression mediated by cyclic AMP, whereas protease production is controlled by a repression mechanism which mimics in part, but may be distinct from catabolite repression.     

Catabolite repression and role of cyclic AMP in CO2 fixation and H2 metabolism in Rhizobium spp.

CO2 fixation in Rhizobium meliloti was repressed by a variety of organic carbon sources. Cellular cyclic AMP levels were similar in repressed and nonrepressed cultures. Exogenous cyclic AMP or additional copies of the adenyl cyclase gene in cells experiencing repression failed to affect the rates of CO2 fixation. However, in R. japonicum catabolite repression of H2 utilization was partially circumvented by the presence of the R. meliloti adenyl cyclase gene.     

Glucose control of staphylococcal enterotoxin A synthesis and location is mediated by cyclic AMP

The regulation of staphylococcal enterotoxin A (SEA) synthesis in a defined medium was studied using continuous culture techniques. SEA production was repressed by glucose and repression could be overcome by addition of exogenous cyclic AMP. As well as this classical catabolite repression control, addition of glucose to de-repressed steady-state cultures resulted in rapid disappearance of toxin from the medium (also mediated by loss of cyclic AMP). When the toxin dissappeared from the medium, it was taken up again by the bacteria without apparent modification.     

Catabolite repression of Pseudomonas aeruginosa amidase: the effect of carbon source on amidase synthesis.

Synthesis of the Pseudomonas aeruginosa aliphatic amidase was repressed severely by succinate and malate and less severely by glucose, acetate or lactate. Amidase synthesis in inducible and constitutive strains was stimulated by cyclic AMP, which also gave partial relief to catabolite repression produced by the addition of lactate to cultures growing in pyruvate medium. Mutants which were resistant to catabolite repression were isolated from succinate+lactamide medium.     

Effects of aerobic and anaerobic shock on catabolite repression in cyclic AMP suppressor mutants of Escherichia coli.

Cultures of Escherichia coli K-12 grown on glucose or gluconate under aerobic conditions exhibited catabolite repression of beta-galactosidase synthesis. Depression occurred when these cultures were subjected to anaerobic shock. These states of repression and depression were found to be associated with low and high differential rates of cyclic AMP synthesis, respectively. This observation is consistent with the view that cyclic AMP plays a central role in the catabolite repression phenomenon. We report here, however, that identical stages of repression and derepression occur in mutant strains possessing cya crp(Csm) genotypes and therefore unable to synthesize cyclic AMP. These results suggest that cyclic AMP is not the sole regulator involved in catabolite repression.     

Repression of arginase and agmatine amidinohydrolase by urea in the lichen Evernia prunastri

Two forms of arginase (EC 3.5.3.1) have been found in Evernia prunastri: (1) a light-arginase (M_r, 180 000) induced by l-arginine—urea causes repression which is reversed by cyclic AMP; (2) a constitutive heavy-arginase (M_r, 330 000) which is not affected by cyclic AMP. Agmatine amidinohydrolase (EC 3.5.3.11) is also repressed by urea but this effect is carried out at catabolite concentrations higher than those required to prevent the synthesis of the light-arginase. This repression is also relieved by cyclic AMP.     

Regulation of transcription of the Escherichia coli phosphoenolpyruvate carboxykinase locus: studies with pck-lacZ operon fusions

Mutants of Escherichia coli containing genetic fusions of lacZ to the pck (phosphoenolpyruvate carboxykinase) locus were isolated by using Mu d(lacZ Ampr) bacteriophage. Synthesis of beta-galactosidase in these strains is regulated by cyclic AMP and glucose (catabolite repression). Synthesis of beta-galactosidase by pck-lacZ fusions was induced in log-phase cells growing on gluconeogenic media, was repressed by glucose, and was also induced up to 100-fold at the onset of stationary phase in LB medium. This stationary-phase induction required cyclic AMP and some other unknown regulatory signal.     

Enzyme induction and repression in Arthrobacter crystallopoietes

Summary Catabolic effects which exert control over the inducible synthesis of three enzymes in Arthrobacter crystallopoietes involve at least three different mechanisms: interference with inducer transport, severe catabolite repression, and transient repression. The rate of histidase induction by histidine is reduced by incubation of the cells with succinate or glucose. The maximum effect of succinate, 67% reduction in histidase production, occurs only after 100 min of incubation with succinate. At least 3h of incubation are required for the maximum effect of glucose (31% reduction in enzyme induction). Both succinate and glucose inhibit histidine transport. Cyclic adenosine 3,5-monophosphate (cyclic AMP), at 10^-7 M, slightly stimulates the induction of histidase in cultures both with or without succinate. No conditions were found in which cyclic AMP abolishes the effect of succinate. Induction of l-serine dehydratase by glycine is severely and permanently repressed by glucose and to a lesser extent by citrate. Glucose does not affect glycine uptake. Succinate, fumarate, and aspartate, which are all better substrates than glucose or citrate for growth of A. crystallopoietes, have no effect on l-serine dehydratase induction. Induction and repression of l-serine dehydratase are not affected by cyclic AMP. Synthesis of isocitrate lyase after addition of acetate is unaffected by glucose but is severely repressed by succinate or fumarate. Aspartate and glutamate cause a transient repression of enzyme synthesis after which synthesis proceeds at the control rate. The ability to transport acetate is inducible. Development of this capacity in the presence of acetate is not affected by succinate or glutamate. Cyclic AMP has no effect on enzyme production or repression. A. crystallopoietes takes up radioactive cyclic AMP and has at least one of the enzymes of cyclic AMP metabolism, adenyl cyclase.     

Catabolite repression of thiosulfate reduction bySalmonella typhimurium

The effect of glucose and other carbon sources on thiosulfate reduction and on the expression ofphs bySalmonella typhimurium was examined. Glucose repressed both H₂S production from thiosulfate and methyl viologen-linked thiosulfate reductase activity. Cyclic AMP (2 mM) in the growth medium restored both activities. Cyclic AMP was essential for both activities in acya mutant. Glucose and many other sugars repressedphs expression in both Cya⁺ and Cya^– phs::Mu d1(Ap^r lac) operon fusion mutants. Increasing cyclic AMP to 10 mM increasedphs expression in the presence of some, but not all, sugars. It appears that catabolite repression of thiosulfate reduction inS. typhimurium involves more than a simple requirement for cyclic AMP.     

Catabolite repression in Escherichia coli mutants lacking cyclic AMP.

Summary The regulation of catabolite repression of -galactosidase has been studied in Escherichia coli mutants deleted for the adenyl cyclase gene (cya ), and thus unable to synthesize cyclic AMP. It has been found that, provided a second mutation occurs either in the crp gene coding for the catabolite gene activator protein (CAP) or in the Lactose region, these mutants exhibit catabolite repression. If the catabolite repression seen in the mutant strains corresponds to the mechanism operating in wild-type cells, the results would suggest that the intracellular concentration of cyclic AMP cannot be the unique regulator of catabolite repression.Jacques Monod was still with us when most of the work described in this and the following paper was accomplished. His constant interest, his unfailing advice, his warm support, were invaluable. It will be difficult for us to ever enjoy a successful experiment without regretting that he cannot share this pleasure with us.     

Regulation of extracellular alkaline protease activity by histidine in a collagenolytic Vibrio alginolyticus strain

Vibrio alginolyticus synthesized an inducible extracellular collagenase in a peptone medium during the stationary growth phase. These cultures also possessed extracellular alkaline serine protease activity. The alkaline protease activity did not require a specific inducer and it was produced in tryptone or minimal media. The collagenase was not produced in either the tryptone or minimal media. The alkaline protease activity was sensitive to catabolite repression by a number of carbon sources, including glucose, and by amino acids and ammonium ions. Cyclic AMP, dibutyryl cyclic AMP and cyclic GMP did not relieve catabolite repression. Histidine and urocanic acid stimulated the production of alkaline protease activity in tryptone and minimal media. Other compounds associated with the histidine utilization (hut) pathway did not increase alkaline protease activity. Histidine reversed the repression of alkaline protease activity by glucose of (NH4)2SO4 in minimal medium. Histidine and the compounds associated with the hut pathway inhibited collagenase production.     

Elevated cyclic AMP concentration in streptomycin-dependent Escherichia coli.

Streptomycin-dependent Escherichic coli B and K-12 cultures, which have relaxed catabolite repression when grown to glucose-salts medium, have an elevated concentration of cyclic AMP.     

Cyclic AMP may not be involved in catabolite repression in Saccharomyces cerevisiae: evidence from mutants unable to synthesize it

Yeast cells with a nonsense adenylate cyclase mutation, cyr1-3, required cyclic AMP for growth. This phenotype was suppressed by the byc1 mutation; however, cyr1-3 bcy1 cells produced no detectable level of adenylate cyclase or cyclic AMP. On induction, the bcy1 and cyr1-3 bcy1 mutant cells produced the same levels of galactokinase and alpha-D-glucosidase as did the wild-type cells and fourfold-higher levels of invertase. Since galactokinase synthesis was severely repressed by glucose in the constitutive GAL81 mutants, irrespective of the cyr1-3 bcy1 genotype, cyclic AMP may not be involved in catabolite repression.     

Release of the β-Galactosidase-Synthesizing System from Ultraviolet Catabolite Repression by Cyclic 3′,5′-Adenosine Monophosphate, Dark Repair, Photoreactivation, and Cold Treatment

Recovery from the inhibitory effect of ultraviolet irradiation on the induced synthesis of beta-galactosidase was studied in Escherichia coli B/r. When irradiated cells (520 ergs/mm(2) at 254 nm) were induced and incubated in minimal medium supplemented with Casamino Acids (conditions of catabolite repression), the ability to form enzyme was greatly reduced for about 100 min and then recovery began. The inhibition observed immediately after ultraviolet irradiation was partially reversed by cyclic 3',5'-adenosine monophosphate (cyclic AMP) or by photoreactivation treatment. Inhibition was reduced if the cells were given cold treatment (5 C) before or during irradiation; the kinetics of induced enzyme formation in each case were similar to those of irradiated cells receiving cyclic AMP. These kinetics suggest that the cold treatments, like cyclic AMP, cause the release of the beta-galactosidase-synthesizing system from catabolite repression. When irradiated cells were incubated for various times before cyclic AMP or photoreactivation treatment, some reversal of the inhibition of induced enzyme formation was obtained, but by 100 min the treatments were ineffective. Because 100 min was also the time at which dark recovery of enzyme formation began, the recovery process was interpreted to be the result of completion of DNA repair, which, in turn, released the beta-galactosidase-synthesizing system from catabolite repression.     

Glucose repression of anaerobic genes of Escherichia coli is independent of cyclic AMP

Abstract Several anaerobically regulated gene fusions were examined for the effects of catabolite repression. Glucose repressed the expression of most of the genes represented in our collection of anaerobically induced fusions. However, addition of cyclic AMP did not reverse the effects of glucose. Furthermore, introduction of cya and crp mutations into selected anaerobically induced fusion strains did not reduce anaerobic gene expression as expected from the known mechanism of aerobic catabolite repression. In fact, in different fusion strains, cya or crp mutations caused from 2 to 20-fold increases in gene expression. Although glucose repression occurs anaerobically its mechanism would appear to be quite different from that under aerobic conditions.     

Cyclic AMP transport across membrane vesicles of ultra-violet light irradiatedEscherichia coli

Transport of cyclic AMP acrossEscherichia coli membrane was studied using membrane vesicles. Uptake of cyclic AMP was measured using normally oriented vesicles, whereas uptake in everted vesicles was taken as a measure of the efflux of cyclic AMP. Ultra-violet irradiation of the cells led to an inhibition of both uptake and efflux of cyclic AMP across the membrane. The presence of cyclic AMP in the growth medium prior to ultra-violet irradiation caused an enhancement of the uptake and efflux. The uptake and efflux of cyclic AMP were less in vesicles from glucose grown cells as compared to the uptake and efflux by the vesicles prepared from glycerol grown cells. Similarly both uptake and efflux of cyclic AMP were more in vesicles prepared from cells grown on glycerol or glucose in the presence of cyclic AMP than in vesicles from cells grown in absence of cyclic AMP. It is suggested that the number of cyclic AMP carrier molecules were reduced in cells under catabolite repression by glucose as well as by ultra-violet irradiation     

Catabolite repression of inositol dehydrogenase and gluconate kinase syntheses in Bacillus subtilis

The regulation of induction of inositol dehydrogenase (EC 1.1.1.18) and gluconate kinase (EC 2.7.1.12) was studied in Bacillus subtilis. Inositol dehydrogenase is induced by myo-inositol and gluconate kinase is induced by D-gluconate. Both inductions were strongly repressed by rapidly metabolizable carbohydrates such as D-glucose, D-mannose, D-fructose and glycerol (D-glucose had the strongest repressive effect) but they were weakly repressed by slowly metabolizable carbohydrates. Although each carbohydrate exerted a stronger effect on the induction of inositol dehydrogenase than that of gluconate kinase, it showed a similar tendency with respect to the degree of repression of each induction. This catabolite repression could not be diminished by addition of cyclic AMP to medium. In addition, non-metabolizable D-glucose analogues had no or weak repressive effects. On the assumption that rapidly metabolizable carbohydrates might be metabolized to repress both inductions, it was investigated whether several mutants blocked in the Embden-Meyerhof pathway could produce metabolite(s) (repressor) to repress them. A phosphoglycerate kinase (EC 2.7.2.3) deficient mutant could produce the repressor from D-glucose, D-mannose, D-fructose and glycerol but other mutants could not produce it from carbohydrates unable to be metabolized ineach mutant. Thus, catabolite repression of both enzyme inductions seemed to be under similar regulation. The identification of the possible repressor of the induction of inositol dehydrogenase and gluconate kinase in vivo was discussed.