Biochemical conservation of recombinant Drosophila tyrosine hydroxylase with its mammalian cognates.
Dopamine modulates several behavioral and developmental events; in the fruit fly Drosophila melanogaster, dopamine is a neurotransmitter, a neuromodulator, and a developmental signal. Studies in mammals suggest that these diverse roles for dopamine have been evolutionarily conserved. Fundamental regulation of dopamine occurs via tyrosine hydroxylase (TH), the first and rate-limiting enzyme in the catecholamine biosynthetic pathway. Mammalian TH is acutely regulated via phosphorylation-dephosphorylation mechanisms, which occur as a direct consequence of nerve stimulation. We have shown that the Drosophila homolog of TH, DTH, shares over 50% sequence identity with mammalian TH, and the serine residue corresponding to the major site of phosphorylation is conserved. We demonstrate using recombinant DTH protein generated in E. coli that its regulatory biochemical mechanisms closely parallel those from mammals. Drosophila thus provides a highly conserved and tractable model system in which to test the functional consequences of perturbing TH activity by acute regulatory mechanisms.
Neckameyer
Wendi S
WS
Department of Pharmacological and Physiological Science, Saint Louis University School of Medicine, St. Louis, Missouri 63104, USA. neckamws@slu.edu
Holt
Bridgette
B
Paradowski
T J
TJ
D000595:Amino Acid Sequence; D000818:Animals; D017124:Conserved Sequence; D004330:Drosophila / Q000201:enzymology* / Q000235:genetics*; D004926:Escherichia coli / Q000235:genetics; D015971:Gene Expression Regulation, Enzymologic; D007700:Kinetics; D008322:Mammals / Q000235:genetics*; D008969:Molecular Sequence Data; D010766:Phosphorylation; D011994:Recombinant Proteins / Q000378:metabolism; D011995:Recombination, Genetic; D017386:Sequence Homology, Amino Acid; D012694:Serine / Q000737:chemistry; D013379:Substrate Specificity; D014446:Tyrosine 3-Monooxygenase / Q000737:chemistry / Q000235:genetics*
D011994:Recombinant Proteins; D012694:Serine; D014446:Tyrosine 3-Monooxygenase