Disease relevance of glgA

• Enhanced symbiotic performance by Rhizobium tropici glycogen synthase mutants [1].
• Biosynthesis of bacterial glycogen. Primary structure of Escherichia coli ADP-glucose:alpha-1,4-glucan, 4-glucosyltransferase as deduced from the nucleotide sequence of the glgA gene [2].
• The structural genes of ADPglucose pyrophosphorylase (glgC) and glycogen synthase (glgA) from Salmonella typhimurium LT2 were cloned on a 5.8-kilobase-pair insert in the SalI site of pBR322 [3].

High impact information on glgA

• Furthermore, this study suggests that the specificity of glycogen synthase and starch synthase and their concerted action with BE play an important role in determining the structure of the polysaccharide synthesized [4].
• The cysteine-specific reagent 5,5'-dithiobis(2-nitrobenzoic acid) inactivates the Escherichia coli glycogen synthase (Holmes, E., and Preiss, J. (1982) Arch. Biochem. Biophys. 216, 736-740) [5].
• The finding that, in early exponential phase, mutant cells contain higher levels of glycogen phosphorylase a, in addition to a lower amount of total glycogen synthase activity observed in medium-late exponential phase, could account for the difference found in glycogen accumulation [6].
• The deduced amino acid sequence was also consistent with the amino-terminal acid sequence and amino acid sequence analysis of various peptides obtained from CNBr degradation of purified glycogen synthase [2].
• In vitro, insulin or TDZD-8 caused similar reductions in the nuclear factor-kappaB p65 activity and similar increases in the phosphorylation of Ser9 of glycogen synthase kinase-3beta [7].

Chemical compound and disease context of glgA

• A chromosomal cluster of genes encoding ADP-glucose synthetase, glycogen synthase and phosphoglucomutase in Agrobacterium tumefaciens [8].

Biological context of glgA

• This mutant had a phenotype similar to that of the Tn5 mutant, indicating that the enhanced respiration and symbiotic nitrogen fixation and decreased exopolysaccharide were due to mutation of glgA and not to a polar effect on a downstream gene [1].
• Alignment of the amino acid sequences of the four mature starch synthases with the Escherichia coli glgA gene product revealed the presence of at least three conserved boxes; there is no homology with previously proposed starch-binding domains of other enzymes involved in starch metabolism [9].
• These residues were essential, validating the model that shows a strong similarity between the active site of E. coli glycogen synthase and the other retaining GT-B glycosyltransferases known to date [10].

Associations of glgA with chemical compounds

• Surprisingly, the glgA mutant had decreased levels of high-molecular-weight exopolysaccharide after growth on glucose, but levels were normal after growth on galactose [1].
• CONCLUSIONS: Therapy with insulin or the potent and selective glycogen synthase kinase-3beta inhibitor TDZD-8 reduced the organ injury/dysfunction caused by lipopolysaccharide and peptidoglycan in the rat [7].
• The potent and selective glycogen synthase kinase-3beta inhibitor TDZD-8 (1 mg/kg intravenously) or vehicle (10% dimethyl sulfoxide) was administered either prophylactically or therapeutically [7].
• However, the prior action of cyclic AMP-dependent protein kinase significantly potentiated the ability of casein kinase I to phosphorylate and inactivate glycogen synthase [11].

Other interactions of glgA

• The gene, glgP, is located immediately downstream from glgA, the gene for glycogen synthase [12].
• The nucleotide sequences of the Escherichia coli genome between the glycogen biosynthetic genes glgB and glgC, and 1170 bp of DNA which follows glgA have been determined [13].
• The cloned region which follows glgA contains an incomplete ORF (1149 bp), glgY, which appears to encode 383 aa of the N terminus of glycogen phosphorylase, based upon sequence similarity with the enzyme from rabbit muscle (47% identical aa residues) and with maltodextrin phosphorylase from E. coli (37% identical aa residues) [13].

Analytical, diagnostic and therapeutic context of glgA

• To confirm the importance of these residues predicted by the model, we studied them in E. coli glycogen synthase by site-directed mutagenesis [10].

References