Regulation and differential expression of <i>gdhA</i> encoding NADP‐specific glutamate dehydrogenase in <i>Neisseria meningitidis</i> clinical isolates

Pagliarulo, Caterina; Salvatore, Paola; Vitis, Lucia Rosaria De; Colicchio, Roberta; Monaco, Caterina; Tredici, M.; Talà, Adelfia; Bardaro, Marcellino; Lavitola, Alfredo; Bruni, Carmelo B.; Alifano, Pietro

doi:10.1111/j.1365-2958.2003.03947.x

Cited by 47 publications

(69 citation statements)

References 32 publications

(39 reference statements)

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“…N. meningitidis strains have been reported previously (2,6,16,25,31,32). In particular, the origin, genotype, and phenotype of B1940 and its derivatives, the B1940 cps mutant, the B1940 siaD(ϪC) mutant, and the B1940 siaD(ϩC) mutant (where ϪC and ϩC indicate the deletion and insertion of a cytosine in a polycytidine repeat in the coding region of siaD, respectively), have been described previously (6,10).…”

Section: Methodsmentioning

confidence: 99%

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TheNeisseria meningitidisCapsule Is Important for Intracellular Survival in Human Cells

et al. 2007

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While much data exist in the literature about how Neisseria meningitidis adheres to and invades human cells, its behavior inside the host cell is largely unknown. One of the essential meningococcal attributes for pathogenesis is the polysaccharide capsule, which has been shown to be important for bacterial survival in extracellular fluids. To investigate the role of the meningococcal capsule in intracellular survival, we used B1940, a serogroup B strain, and its isogenic derivatives, which lack either the capsule or both the capsule and the lipooligosaccharide outer core, to infect human phagocytic and nonphagocytic cells and monitor invasion and intracellular growth. Our data indicate that the capsule, which negatively affects bacterial adhesion and, consequently, entry, is, in contrast, fundamental for the intracellular survival of this microorganism. The results of in vitro assays suggest that an increased resistance to cationic antimicrobial peptides (CAMPs), important components of the host innate defense system against microbial infections, is a possible mechanism by which the capsule protects the meningococci in the intracellular environment. Indeed, unencapsulated bacteria were more susceptible than encapsulated bacteria to defensins, cathelicidins, protegrins, and polymyxin B, which has long been used as a model compound to define the mechanism of action of CAMPs. We also demonstrate that both the capsular genes (siaD and lipA) and those encoding an efflux pump involved in resistance to CAMPs (mtrCDE) were up-regulated during the intracellular phase of the infectious cycle.

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Section: Methodsmentioning

confidence: 99%

“…The procedure for limited transcriptional analysis has been detailed previously (22,25). Briefly, a partial Sau3AI-restricted genomic library from serogroup B strain H44/76 was constructed.…”

Section: Methodsmentioning

confidence: 99%

TheNeisseria meningitidisCapsule Is Important for Intracellular Survival in Human Cells

et al. 2007

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“…The induction of NAD-, NADP-or NAD(P)-GDH has also been reported under varying environmental conditions such as salt (Bonete et al, 1990(Bonete et al, , 2003, temperature (Camardella et al, 2002) and nitrogen source (Abrahams & Abratt, 1998;Brown et al, 1973;LeJohn & McCrea, 1968). In Neisseria meningitidis, transcriptional analysis has shown carbon source-dependent expression of gdhA, leading to a difference in the growth of the strain (Pagliarulo et al, 2004).…”

Section: Discussionmentioning

confidence: 99%

Carbon source-dependent modulation of NADP-glutamate dehydrogenases in isophthalate-degrading Pseudomonas aeruginosa strain PP4, Pseudomonas strain PPD and Acinetobacter lwoffii strain ISP4

Vamsee-Krishna

Phale

2008

Microbiology

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Acinetobacter lwoffii strain ISP4 metabolizes isophthalate rapidly compared with Pseudomonas aeruginosa strain PP4 and Pseudomonas strain PPD. Isophthalate has been reported to be a potent competitive inhibitor of glutamate dehydrogenase (GDH). Exogenous supplementation of isophthalate with glutamate or a-ketoglutarate at 1 mM concentration caused strains PP4 and PPD to grow faster than in the presence of isophthalate alone; however, no such effect was observed in strain ISP4. When grown on isophthalate, all strains showed activity of NADPdependent GDH (NADP-GDH), while cells grown on glucose, 2¾ yeast extract-tryptone broth (2YT) or glutamate showed activities of both NAD-dependent GDH (NAD-GDH) and NADP-GDH. Activity staining, inhibition and thermal stability studies indicated the carbon sourcedependent presence of two (GDH I and GDH II ), three (GDH A , GDH B and GDH C ) and one (GDH P ) forms of NADP-GDH in strains PP4, PPD and ISP4, respectively. The results demonstrate the carbon source-dependent modulation of different forms of NADP-GDH in these bacterial strains. This modulation may help the efficient utilization of isophthalate as a carbon source by overcoming the inhibitory effect on GDH.

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“…Organic acids are known to act as effector molecules of the FadR-binding proteins which are involved in regulation of fatty acid biosynthesis and degradation in Escherichia coli (Pagliarulo et al, 2004). As outlined above, the 2-oxoglutarate concentration is highly elevated in a DgdhA strain, which is a requirement for the thermodynamically unfavoured reaction, catalysed by GDHB, to take over the production of glutamate.…”

Section: Strainmentioning

confidence: 99%

NADPH-dependent glutamate dehydrogenase in Penicillium chrysogenum is involved in regulation of β-lactam production

Thykaer

Rueksomtawin

Noorman³

et al. 2008

Microbiology

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The interactions between the ammonium assimilatory pathways and b-lactam production were investigated by disruption of the NADPH-dependent glutamate dehydrogenase gene (gdhA) in two industrial b-lactam-producing strains of Penicillium chrysogenum. The strains used were an adipoyl-7-ADCA-and a penicillin-producing strain. The gdhA gene disruption caused a decrease in maximum specific growth rate of 26 % and 35 % for the adipoyl-7-ADCA-producing strain and the penicillin-producing strain, respectively, compared to the corresponding reference strains. Interestingly, no b-lactam production was detected in either of the DgdhA strains. Supplementation with glutamate restored growth but no b-lactam production was detected for the constructed strains. Cultures with high ammonium concentrations (repressing conditions) and with proline as nitrogen source (de-repressed conditions) showed continued b-lactam production for the reference strains whereas the DgdhA strains remained non-productive under all conditions. By overexpressing the NAD-dependent glutamate dehydrogenase, the specific growth rate could be restored, but still no b-lactam production was detected. The results indicate that the NADPH-dependent glutamate dehydrogenase may be directly or indirectly involved in the regulation of b-lactam production in industrial strains of P. chrysogenum.

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Regulation and differential expression of gdhA encoding NADP‐specific glutamate dehydrogenase in Neisseria meningitidis clinical isolates

Cited by 47 publications

References 32 publications

TheNeisseria meningitidisCapsule Is Important for Intracellular Survival in Human Cells

TheNeisseria meningitidisCapsule Is Important for Intracellular Survival in Human Cells

Carbon source-dependent modulation of NADP-glutamate dehydrogenases in isophthalate-degrading Pseudomonas aeruginosa strain PP4, Pseudomonas strain PPD and Acinetobacter lwoffii strain ISP4

NADPH-dependent glutamate dehydrogenase in Penicillium chrysogenum is involved in regulation of β-lactam production

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