Role of cAMP in the mediation of glucose catabolite repression of glucoamylase synthesis in Aspergillus awamori

1988 ◽  
Vol 14 (3) ◽  
pp. 247-252 ◽  
Author(s):  
Resham S. Bhella ◽  
Illimar Altosaar
Keyword(s):  
Catabolite Repression ◽  
Aspergillus Awamori

scholarly journals Crc Is Involved in Catabolite Repression Control of the bkd Operons of Pseudomonas putida andPseudomonas aeruginosa

2000 ◽  
Vol 182 (4) ◽  
pp. 1144-1149 ◽  
Author(s):  
Kathryn L. Hester ◽  
Jodi Lehman ◽  
Fares Najar ◽  
Lin Song ◽  
Bruce A. Roe ◽  
...  
Keyword(s):  
Pseudomonas Putida ◽  
Catabolite Repression ◽  
Carbon Sources ◽  
Keto Acid ◽  
Carbon Regulation ◽  
Acid Dehydrogenase ◽  
Transposon Mutants ◽  
Branched Chain ◽  
Glucose 6 Phosphate Dehydrogenase

ABSTRACT Crc (catabolite repression control) protein of Pseudomonas aeruginosa has shown to be involved in carbon regulation of several pathways. In this study, the role of Crc in catabolite repression control has been studied in Pseudomonas putida. The bkd operons of P. putida and P. aeruginosa encode the inducible multienzyme complex branched-chain keto acid dehydrogenase, which is regulated in both species by catabolite repression. We report here that this effect is mediated in both species by Crc. A 13-kb cloned DNA fragment containing the P. putida crc gene region was sequenced. Crc regulates the expression of branched-chain keto acid dehydrogenase, glucose-6-phosphate dehydrogenase, and amidase in both species but not urocanase, although the carbon sources responsible for catabolite repression in the two species differ. Transposon mutants affected in their expression of BkdR, the transcriptional activator of thebkd operon, were isolated and identified as crcand vacB (rnr) mutants. These mutants suggested that catabolite repression in pseudomonads might, in part, involve control of BkdR levels.

scholarly journals Carbon catabolite repression in pectin digestion by phytopathogen Dickeya dadantii

2021 ◽  
Author(s):  
Shiny Martis B ◽  
Michel Droux ◽  
William Nasser ◽  
Sylvie Reverchon ◽  
Sam Meyer
Keyword(s):  
Catabolite Repression ◽  
Carbon Catabolite Repression ◽  
Degradation Pathway ◽  
Hplc Method ◽  
Metabolic Switch ◽  
Dickeya Dadantii ◽  
Transcriptional Regulatory ◽  
Genes Encoding ◽  
Regulatory Model

The catabolism of pectin from the plant cell walls plays a crucial role in the virulence of the phytopathogen Dickeya dadantii. In particular, the timely expression of pel genes encoding major pectate lyases is essential to circumvent the plant defense systems and induce a massive pectinolytic activity during the maceration phase. While previous studies identified the role of a positive feedback loop specific to the pectin degradation pathway, here we show that the pel> expression pattern is controlled by a metabolic switch between glucose and pectin. We develop a dynamical and quantitative regulatory model of this process integrating the two main regulators CRP and KdgR related to these two sources of carbon, and reproducing the concentration profiles of the associated metabolites, cAMP and KDG respectively, quantified using a new HPLC method. The model involves only 5 adjustable parameters, and recapitulates the dynamics of these metabolic pathways during bacterial growth together with the regulatory events occurring at the promoters of two major pel genes, pelE and pelD. It highlights their activity as an instance of carbon catabolite repression occurring at the transcriptional regulatory level, and directly related to the virulence of D. dadantii. The model also shows that quantitative differences in the binding properties of common regulators at these two promoters resulted in a qualitative different role of pelD and pelE in the metabolic switch, and also likely in conditions of infection, explaining their evolutionary conservation as separate genes in this species.

Modeling the role of cyclic AMP in catabolite repression of inducible enzyme biosynthesis in mircobial cells

1978 ◽  
Vol 20 (11) ◽  
pp. 1797-1815 ◽  
Author(s):  
Shinichiro Gondo ◽  
K. Venkatasubramanian ◽  
Wolf R. Vieth ◽  
A. Constantinides
Keyword(s):  
Cyclic Amp ◽  
Catabolite Repression ◽  
Inducible Enzyme ◽  
Enzyme Biosynthesis

Role of bacterial virulence proteins in Agrobacterium-mediated transformation of Aspergillus awamori

2004 ◽  
Vol 41 (5) ◽  
pp. 571-578 ◽  
Author(s):  
C.B. Michielse ◽  
A.F.J. Ram ◽  
P.J.J. Hooykaas ◽  
C.A.M.J.J.van den Hondel
Keyword(s):  
Bacterial Virulence ◽  
Aspergillus Awamori ◽  
Agrobacterium Mediated Transformation ◽  
Virulence Proteins

scholarly journals The role of the regulator-gene product (repressor) in catabolite repression of β-galactosidase synthesis in Escherichia coli

1968 ◽  
Vol 106 (2) ◽  
pp. 339-343 ◽  
Author(s):  
J. Palmer ◽  
V. Moses
Keyword(s):  
Escherichia Coli ◽  
Gene Product ◽  
Catabolite Repression ◽  
Lac Repressor ◽  
Temperature Sensitive ◽  
Sensitive Mutant ◽  
Amber Suppressor ◽  
Transient Repression ◽  
I Gene

1. The specific role of the lac repressor (i-gene product) in transient catabolite repression evoked by the introduction of glucose into the medium has been investigated in Escherichia coli by using mutants of the i-gene. 2. A temperature-sensitive mutant (iTL) is normally inducible and demonstrates transient repression when grown at 32°. At 42° it is about 20% constitutive and transient catabolite repression is abolished. 3. A strain carrying an amber suppressor-sensitive mutation in the i-gene is phenotypically constitutive and also fails to show transient catabolite repression. 4. Insertion of Flaci+ into this strain restores both inducibility and transient repression. 5. It is concluded that the i-gene product interacts with the catabolite co-repressor in such a way that its affinity for the operator is increased.

Sign in / Sign up

Export Citation Format

Share Document