Transport and Catabolism of Carbohydrates by Neisseria meningitidis

Abstract

We identified the genes encoding the proteins for the transport of glucose and maltose in Neisseria meningitidis strain 2C4-3. A mutant deleted for NMV_1892(glcP) no longer grew on glucose and deletion of NMV_0424(malY) prevented the utilization of maltose. We also purified and characterized glucokinase and α-phosphoglucomutase, which catalyze early catabolic steps of the two carbohydrates. N. meningitidis catabolizes the two carbohydrates either via the Entner-Doudoroff (ED) pathway or the pentose phosphate pathway, thereby forming glyceraldehyde-3-P and either pyruvate or fructose-6-P, respectively. We purified and characterized several key enzymes of the two pathways. The genes required for the transformation of glucose into gluconate-6-P and its further catabolism via the ED pathway are organized in two adjacent operons. N. meningitidis also contains genes encoding proteins which exhibit similarity to the gluconate transporter (NMV_2230) and gluconate kinase (NMV_2231) of Enterobacteriaceae and Firmicutes. However, gluconate might not be the real substrate of NMV_2230 because N. meningitidis was not able to grow on gluconate as the sole carbon source. Surprisingly, deletion of NMV_2230 stimulated growth in minimal medium in the presence and absence of glucose and drastically slowed the clearance of N. meningitidis cells from transgenic mice after intraperitoneal challenge.

Transcriptome guided metabolic network analysis reveals rearrangements of carbon flux distribution inNeisseria gonorrhoeaeduring neutrophil co-culture

“…Characteristics of the original Nmb_iTM560 model were conserved, including the presence of a periplasmic compartment, simplified cytochrome respiration pathways, iron acquisition pathways from ferric iron and host proteins, and a biomass equation that reflects the neisserial cell composition. Targets for manual curation of the automated reconstruction in iNgo_557 included complete resolution of mass and charge balance inconsistencies, the resolution of import and export loops, removal of carbohydrate import through the phosphotransferase system (which is not functional in pathogenic Neisseria ) (23), addition of amino acid catabolism pathways, curation of lipooligosaccharide synthesis for Gc and its addition to the biomass equation, modification of the biomass composition for Gc where appropriate, and simplification of lipid biosynthesis ( Dataset S1 ). Additionally, catalytic cofactors such as biotin, thiamine pyrophosphate, pyridoxal-5-phosphate, iron, zinc, manganese, NAD, and FAD were removed.…”

“…More recently, these tools have been used for the integration and interpretation of multi-omics data and applied to studies of human health and disease, including modeling of the metabolism of prominent human pathogens including Mycobacterium tuberculosis, Staphylococcus aureus, Pseudomonas aeruginosa, Clostridioides difficile, and Salmonella typhimurium (19)(20)(21). In contrast, there is no published model of Gc metabolism; while there is a GENRE for the related N. meningitidis (22), these two species are known to have key differences in their metabolism, for instance in sugar utilization (23). Moreover, few studies to date have applied metabolic modeling to pathogens in the context of immune cells, leaving a gap in knowledge of how immunedriven metabolic shifts shape bacterial metabolism.…”

A central role of sibling sRNAs NgncR_162/163 in main metabolic pathways of Neisseria gonorrhoeae

“…Lactate permease is considered as a virulence factor of N. gonorrhoeae , since lctP deficient mutants are attenuated in a murine model of lower genital tract infection (Exley et al, 2011). It should be noted that RNA-seq also suggested positive regulation of NGFG_02263, encoding the ortholog of the menincococcal sole glucose transporter (Derkaoui et al, 2016), by the sibling sRNAs. In N. meningitidis , deletion of hfq resulted in downregulation of the glucose transporter transcript arguing in favour of direct or indirect sRNA-mediated expression control (Fantappié et al, 2011).…”

“…Interestingly, expression of the ED pathway enzymes glucose 6-phosphate 1dehydrogenase (zwf) and 6-phosphogluconolactonase (pgl) in meningococci was reported to be negatively regulated by the transcription factor GdhR (Monaco et al, 2006), which itself is under negative control of the sibling sRNAs in N. gonorrhoeae (Bauer et al, 2017). Furthermore, in meningococci it was shown that ED pathway genes are upregulated in the presence of glucose, while TCA cycle genes and gdhR are downregulated (Antunes et al, 2016). However, zwf and pgl were not differentially expressed in a gdhR mutant of N. gonorrhoeae (Ayala & Shafer, 2019) and, consistently, we did not detect changes in zwf mRNA amounts in mutant ΔΔ162/163 by qRT-PCR (data not shown).…”

Central Role of Sibling Small RNAs NgncR_162 and NgncR_163 in Main Metabolic Pathways of Neisseria gonorrhoeae

“…Lactate permease is considered a virulence factor of N. gonorrhoeae , since lctP -deficient mutants are attenuated in a murine model of lower genital tract infection ( 66 ). It should be noted that RNA-seq also suggested the positive regulation of the NGFG_02263 gene, encoding the ortholog of the meningococcal sole glucose transporter ( 67 ), by the sibling sRNAs. In N. meningitidis , deletion of hfq resulted in downregulation of the glucose transporter transcript, arguing in favor of direct or indirect sRNA-mediated expression control ( 25 ).…”