Bacterial Glycogen Inclusions: Enzymology and Regulation of Synthesis

Preiss, Jack

doi:10.1007/3-540-33774-1_4

Cited by 15 publications

(9 citation statements)

References 168 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…G1P is then converted by GlgCD (ADP-Glc-PP) into ADP-glucose ( Ballicora et al, 2003 ; Diez et al, 2013 ) that serves as the sugar-nucleotide donor for GlgA to elongate α-1,4 glucan chains ( Preiss, 2009 ; Wilson et al, 2010 ). Formation of ADP-glucose is allosterically activated by high-energy metabolites, such as PEP, F6P, G6P, and F-1,6-bP, while the reaction itself is easily reversible and mostly driven by availability of the substrates ( Preiss, 2006 ; Wilson et al, 2010 ). Degradation of IPS is carried out by a glycogen phosphorylase enzyme ( phsG/glgP ) that removes individual glucose moieties from the non-reducing end of the polysaccharides and releases G1P for glycolysis ( Alonso-Casajús et al, 2006 ; Wilson et al, 2010 ; Sato et al, 2013 ).…”

Section: Discussionmentioning

confidence: 99%

“…Under feast conditions, the major etiological agent of dental caries, Streptococcus mutans , is able to produce organic acids and also to convert the excess carbohydrates into intracellular polysaccharides (IPS; Huis In’t Veld and Backer Dirks, 1978 ; Wilson et al, 2010 ), a glycogen ( glg )-like molecule composed primarily of α-1,4-linked glucose polymers. Past research suggests that IPS could play an important role as a storage compound ( Preiss, 2006 ; Busuioc et al, 2009 ), as S. mutans enzymes subsequently break down IPS and release glucose once extracellular carbohydrate sources have been depleted. Thus, IPS is expected to promote bacterial survival, especially during carbohydrate starvation periods ( Spatafora et al, 1995 ; Busuioc et al, 2009 ; Demonte et al, 2017 ).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

The Route of Sucrose Utilization by Streptococcus mutans Affects Intracellular Polysaccharide Metabolism

et al. 2021

View full text Add to dashboard Cite

Streptococcus mutans converts extracellular sucrose (Suc) into exopolysaccharides (EPS) by glucosyl-transferase and fructosyl-transferase enzymes and internalizes Suc for fermentation through the phosphotransferase system (PTS). Here, we examined how altering the routes for sucrose utilization impacts intracellular polysaccharide [IPS; glycogen, (glg)] metabolism during carbohydrate starvation. Strain UA159 (WT), a mutant lacking all exo-enzymes for sucrose utilization (MMZ952), and a CcpA-deficient mutant (∆ccpA) were cultured with sucrose or a combination of glucose and fructose, followed by carbohydrate starvation. At baseline (0h), and after 4 and 24h of starvation, cells were evaluated for mRNA levels of the glg operon, IPS storage, glucose-1-phosphate (G1P) concentrations, viability, and PTS activities. A pH drop assay was performed in the absence of carbohydrates at the baseline to measure acid production. We observed glg operon activation in response to starvation (p<0.05) in all strains, however, such activation was significantly delayed and reduced in magnitude when EPS synthesis was involved (p<0.05). Enhanced acidification and greater G1P concentrations were observed in the sucrose-treated group, but mostly in strains capable of producing EPS (p<0.05). Importantly, only the WT exposed to sucrose was able to synthesize IPS during starvation. Contrary to CcpA-proficient strains, IPS was progressively degraded during starvation in ∆ccpA, which also showed increased glg operon expression and greater PTS activities at baseline. Therefore, sucrose metabolism by secreted enzymes affects the capacity of S. mutans in synthesizing IPS and converting it into organic acids, without necessarily inducing greater expression of the glg operon.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

The Route of Sucrose Utilization by Streptococcus mutans Affects Intracellular Polysaccharide Metabolism

et al. 2021

View full text Add to dashboard Cite

show abstract

“…Glycogen is a reserve glucose polysaccharide occurring in many bacteria, with properties similar to those of animal glycogen (Preiss, 1984(Preiss, , 2006. Its metabolism in bacteria has been extensively studied and involves enzymes such as ADPglucose pyrophosphorylase, ADP-glucose glycogen synthase, glycogen branching enzyme, glycogen phosphorylase and glycogen debranching enzyme (Lepek et al, 2002).…”

Section: Discussionmentioning

confidence: 99%

Glycogen phosphorylase is involved in stress endurance and biofilm formation inAzospirillum brasilenseâSp7

Lerner

Castro‐Sowinski

Lerner

et al. 2009

FEMS Microbiology Letters

View full text Add to dashboard Cite

Here we report the identification of a glycogen phosphorylase (glgP) gene in the plant growth-promoting rhizobacterium Azospirillum brasilense, Sp7, and the characterization of a glgP marker exchange mutant of this strain. The glgP mutant showed a twofold reduction of glycogen phosphorylase activity and an increased glycogen accumulation as compared with wild-type Sp7, indicating that the identified gene indeed encodes a protein with glycogen phosphorylase activity. Interestingly, the glgP mutant had higher survival rates than the wild type after exposure to starvation, desiccation and osmotic pressure. The mutant was shown to be compromised in its biofilm formation ability. Analysis of the exopolysaccharide sugar composition of the glgP mutant revealed a decrease in the amount of glucose, accompanied by increases in rhamnose, fucose and ribose, as compared with the Sp7 exopolysaccharide. To the best of our knowledge, this is the first study that demonstrates GlgP activity in A. brasilense, and shows that glycogen accumulation may play an important role in the stress endurance of this bacterium.

show abstract

“…in Streptococcus mutans , which contributes to the formation of dental caries). Historically, bacteria have been considered to synthesize glycogen using the classical GlgC-GlgA pathway () (reviewed by Preiss, 2006). This involves generating an activated glucose nucleotide diphosphate from glucose 1-phosphate by the action of nucleotide diphosphoglucose pyrophosphorylase (GlgC), and its subsequent polymerization by glycogen synthase (GlgA), to generate the linear glucan.…”

Section: Introduction: the Classical View Of The Metabolism And Functmentioning

confidence: 99%

Unexpected and widespread connections between bacterial glycogen and trehalose metabolism

2011

View full text Add to dashboard Cite

Glycogen, a large α-glucan, is a ubiquitous energy storage molecule among bacteria, and its biosynthesis by the classical GlgC-GlgA pathway and its degradation have long been well understood – or so we thought. A second pathway of α-glucan synthesis, the four-step GlgE pathway, was recently discovered in mycobacteria. It requires trehalose as a precursor, and has been genetically validated as a novel anti-tuberculosis drug target. The ability to convert glycogen into trehalose was already known, so the GlgE pathway provides a complementary way of cycling these two metabolites. As well as containing cytosolic storage glycogen, mycobacteria possess an outer capsule containing a glycogen-like α-glucan that is implicated in immune system evasion, so the GlgE pathway might be linked to capsular α-glucan biosynthesis. Another pathway (the Rv3032 pathway) for α-glucan biosynthesis in mycobacteria generates a methylglucose lipopolysaccharide thought to be associated with fatty acid metabolism. A comparative genomic analysis was carried out to evaluate the occurrence and role of the classical pathway, the new GlgE pathway and the Rv3032 pathway across bacteria occupying very different ecological niches. The GlgE pathway is represented in 14 % of sequenced genomes from diverse bacteria (about half as common as the classical pathway), while the Rv3032 pathway is restricted with few exceptions to mycobacteria, and the GlgB branching enzyme, usually presumed to be associated with the classical pathway, correlates more strongly with the new GlgE pathway. The microbiological implications of recent discoveries in the light of the comparative genomic analysis are discussed.

show abstract

Bacterial Glycogen Inclusions: Enzymology and Regulation of Synthesis

Cited by 15 publications

References 168 publications

The Route of Sucrose Utilization by Streptococcus mutans Affects Intracellular Polysaccharide Metabolism

The Route of Sucrose Utilization by Streptococcus mutans Affects Intracellular Polysaccharide Metabolism

Glycogen phosphorylase is involved in stress endurance and biofilm formation inAzospirillum brasilenseâSp7

Unexpected and widespread connections between bacterial glycogen and trehalose metabolism

Contact Info

Product

Resources

About

Bacterial Glycogen Inclusions: Enzymology and Regulation of Synthesis

Cited by 15 publications

References 168 publications

The Route of Sucrose Utilization by Streptococcus mutans Affects Intracellular Polysaccharide Metabolism

The Route of Sucrose Utilization by Streptococcus mutans Affects Intracellular Polysaccharide Metabolism

Glycogen phosphorylase is involved in stress endurance and biofilm formation inAzospirillum brasilenseâSp7

Unexpected and widespread connections between bacterial glycogen and trehalose metabolism

Contact Info

Product

Resources

About

Glycogen phosphorylase is involved in stress endurance and biofilm formation inAzospirillum brasilenseâSp7