High impact information on Men

• Assays for enzyme activity levels showed that the activities of alpha-glycerophosphate dehydrogenase, alcohol dehydrogenase, and malic enzyme were higher in the fast than in the slow line, but that the activity of superoxide dismutase was lower in the fast line [1].
• By immunological techniques, two natural null variants of malic enzyme and one of phosphoglucose isomerase were shown to be negative to cross-reacting material [2].
• The pentose-phosphate shunt and malic enzyme could supply NADPH necessary for lipid synthesis from ethanol [3].
• The distal 45% of the X chromosome, when duplicated, caused a significant increase in NADP-malic enzyme activity and CRM levels, as if a structural gene for NADP-ME is sex-linked [4].
• 3AT inhibited up to 80% of the catalase activity with concordant small increases in the in vitro activities of sn-glycerol-3-phosphate dehydrogenase, fumarase, and malic enzyme, but with a 16% reduction in the in vivo incorporation of label from [14C]glucose into lipid [5].

Biological context of Men

• By using mutation in the Men gene and deficiencies uncovering this locus, we could show that the ME activity recovered in cytosolic fractions originates exclusively from the Men gene located at map position 87D-1 on the right arm of the 3rd chromosome [6].
• A number of null alleles have been recovered; heterozygotes for these nulls and a Men deficiency are both viable and fertile [7].
• The genetic and cytogenetic locations of the structural gene (Men) for malic enzyme have been determined [7].
• The occurrence of crossing over in Drosophila imeretensis males, as well as the tetrameric structure of malic enzyme, was confirmed [8].
• During the early through middle period of the last larval instar, when ecdysone levels are low, MDH responded to JH rapidly by increasing activity, while little or no response was measured in mature larvae (postfeeding stage) and fresh pupae when the endogenous pulse of ecdysone is high [9].

Anatomical context of Men

• NADP-malic enzyme (NADP-ME) (E.C. 1.1.1.40) is situated in the cytosol of Drosophila melanogaster [10].

Associations of Men with chemical compounds

• The Drosophila malate dehydrogenase, or malic enzyme (ME) encoded by the Men gene, is a non-mitochondrial enzyme recovered in the cytosolic fraction [6].
• In addition, high/low sucrose diet fed to wild types or mutants affected the activity of larval MDH, but the enzyme remained sensitive to administration of JH [9].
• The activity of Drosophila cytosolic malate dehydrogenase (MDH; EC 1.1.1.40), a key enzyme in the biosynthesis of lipids, was found to be regulated by both the sesquiterpenoid juvenile hormone (JH), and the steroid hormone ecdysone [9].
• 2. The allozyme forms (MDH A, MDH B, MDH C) were indistinguishable in terms of NAD and L-malate optima, while they are distinguishable in terms of NADH and OAA saturation conditions [11].

Other interactions of Men

• The mex1 mutant allele is associated with statistically significant decreases in malic enzyme (ME) specific activity and ME specific immunologically cross-reacting material (ME-CRM) in newly emerged adult males [12].
• We have investigated 13 alleles of four genes coding for acid phosphatase, alpha- and beta-esterases, and malic enzyme [8].
• The biochemical phenotype of this mutant strain includes a coordinate reduction in malic enzyme (ME) specific activity and CRM and an increase in specific activity for the pentose-phosphate shunt enzymes, 6-phosphogluconate dehydrogenase and glucose-6-phosphate dehydrogenase [13].

References