FAD-dependent glycerol-3-phosphate dehydrogenase (G3PDH; <db_xref db="EC" dbkey="1.1.99.5"/>) catalyzesthe conversion of glycerol-3-phosphate into dihydroxyacetone phosphate:<reaction> sn-glycerol-3-phosphate + acceptor = glycerone phosphate + reduced acceptor</reaction>Insulin exposure often stimulates G3PDHactivity [<cite idref="PUB00000242"/>, <cite idref="PUB00001977"/>], and thus is key to reducing the effects of the diseasediabetes. In obese people, where insulin resistance has been demonstrated,the amount of G3PDH has been shown to be correspondingly lower thanthat in normal weight people [<cite idref="PUB00000242"/>].In bacteria [<cite idref="PUB00002130"/>] it is associated with the utilization of glycerol coupled torespiration. In <taxon tax_id="562">Escherichia coli</taxon> and <taxon tax_id="727">Haemophilus influenzae</taxon>, two isozymes are known: one expressed underanaerobic conditions (gene glpA) and one in aerobic conditions (gene glpD). Ineukaryotes, a mitochondrial form of GPD participates in the glycerol phosphateshuttle in conjunction with an NAD-dependent cytoplasmic GPD (<db_xref db="EC" dbkey="1.1.1.8"/>) [<cite idref="PUB00005648"/>, <cite idref="PUB00002843"/>]. This mechanism is responsible forthe preservation of a redox balance [<cite idref="PUB00000544"/>, <cite idref="PUB00005664"/>]. In this environment, the enzymehas been recorded to increase activity in the presence of calcium [<cite idref="PUB00000164"/>].These enzymes are proteins of about 60 to 70 Kd which contain a probableFAD-binding domain in their N-terminal extremity. The mammalian enzyme differsfrom the bacterial or yeast proteins by having an EF-hand calcium-bindingregion (see <db_xref db="PROSITEDOC" dbkey="PDOC00018"/>) in its C-terminal extremity. FAD-dependent glycerol-3-phosphate dehydrogenase