High impact information on Pgm

• The enzymes catalyzing near-equilibrium reactions, phosphoglucose isomerase, phosphoglucomutase, and triosephosphate isomerase fail to show any decline in flight performance even when activity levels are reduced to 17% or less [1].
• A single Pgm haplotype defined by two amino acid polymorphisms shows the strongest correlation with latitude and the steepest change in allele frequency across the cline [2].
• Our recent DNA sequence investigation of Pgm found extensive cryptic amino acid polymorphism segregating with the allozyme alleles [2].
• In this study, we characterize the geographic variation of Pgm amino acid polymorphisms at the nucleotide level along a latitudinal cline in the eastern United States. A survey of 15 SNPs across the Pgm gene finds significant clinal differentiation for the allozyme polymorphisms as well as for many of the cryptic amino acid polymorphisms [2].
• We find a twofold difference in activity among PGM protein haplotypes that is associated with a threefold difference in glycogen content [3].

Biological context of Pgm

• In contrast, there is no consistent evidence for the latitudinal cline in Pgm gene frequencies in any of the three zones with Pgm1.00 frequency generally about 85 per cent and Pgm1.20 and Pgm0.70 frequencies each between 5 per cent and 10 per cent [4].
• Our experiment showed that selection did operate on a region of the chromosome marked by Pgm, but that no evidence of selection at loci marked by Est-6 was apparent [5].
• There is also strong linkage disequilibrium across the 2354 bp of the Pgm locus, which may be explained by a specific amino acid haplotype that is high in frequency yet contains an excess of singleton polymorphisms [6].
• Under the conditions tested, altered Pgm gene expression had no detectable effect on adult Drosophila lifespan [7].
• RESULTS: The Pgm alleles were cloned and sequenced and were found to differ by amino-acid substitutions consistent with the relative electrophoretic mobilities of the proteins [7].

Anatomical context of Pgm

• PGM was present in tissues that were shown previously to express Myosin VI, such as the ovarian follicle epithelium, and the individualization complex; and in other tissues, including the trachea, the midgut, the salivary glands and the imaginal discs [8].

Associations of Pgm with chemical compounds

• Endogenous Pgm RNA levels in adult flies were found to be reduced or eliminated by doxycycline treatment in five independent inverted-repeat transgenic lines [7].
• The latitudinal clines for several Pgm amino acid polymorphisms show that high PGM activity, and apparently higher flux to glycogen synthesis, parallel the low activity clines at G6PD for reduced pentose shunt flux in northern latitudes [3].
• Allele frequency shifts to 6-phosphogluconate dehydrogenase and phosphoglucomutase were observed in 5% oxygen, and a shift of alpha-glycerophosphate dehydrogenase allele frequencies occurred in 60% oxygen [9].
• Enhanced phosphorylation and enzymatic activity of phosphoglucomutase by the Btk29A tyrosine kinase in Drosophila [10].

Other interactions of Pgm

• Latitudinal relationships of esterase-6 and phosphoglucomutase gene frequencies in Drosophila melanogaster [4].
• Isocitrate dehydrogenase and phosphoglucomutase were visualized after starch gel electrophoresis of trypanosome lysates [11].
• We have assayed four polymorphic enzyme loci, fairly closely linked in the third chromosome: Sod Est-6, Pgm, and Odh [12].
• Significant genotype--environment associations were found for five of the six loci, and after correcting for geographic location significant associations remained for Est-2 and Adh-1 gene frequencies and heterozygosities and for Pgm gene frequencies [13].

Analytical, diagnostic and therapeutic context of Pgm

• Phosphoglucomutase (PGM) of adult stage in Drosophilia melanogaster has been characterized by gel filtration, ion-exchange chromatography, and isoelectric focusing [14].
• Pgm allele frequencies of 383 individuals were determined in a sample of Drosophila melanogaster from three laboratory Sardinian populations, using the techniques of standard electrophoresis, heat denaturation, and isoelectric focusing [15].

References