NBAD-hydrolase processing in brain and epidermis of Drosophila melanogaster.

SABIO, G; QUESADA-ALLUÉ, L.A.; PÉREZ, M.M.

DROSOPHILA INFORMATION SERVICE

University of Oklahoma

Lugar: Norman, Oklahoma, Estados Unidos de Norte America; Año: 2011 vol. 94 p. 100 - 104

0070-7333

In recent years, research on N-β-alanyl-derivative metabolism in insects has shed new light on its physiological relevance. While NBAD (N-β-alanyldopamine), the first conjugate studied in this metabolism, was originally described as the main sclerotization precursor of insect brown cuticles , new roles have been proposed in neural tissue. Another studied N-β-alanyl-derivative is carcinine (N-β-alanylhistamine, NBAHA), which has been suggested as of physiological importance for the visual system. Both NBAHA and NBAD have been proposed as shuttle/recycling agents of histamine (HA) and dopamine (DA), between glial and neuronal cells. NBAD and NBAHA are both synthesized by the same enzyme: NBAD-synthase, also known as Ebony protein in Drosophila melanogaster.The hydrolysis of these conjugates is catalyzed by NBAD-hydrolase (also known as Tan), which is encoded in D. melanogaster by the gene tan. Tan was described as a homo-dimeric protein with subunits of around 30 and 15 kDa apparent molecular weight (aMW). Apparently, these subunits arise from selfprocessing of a precursor polypeptide of around 45 kDa. A Gly-Cys motif, at position 121, was crucial for this self-processing, and the Tan1 mutant protein, with an Arg for Pro mutation (at position 217), showed no processing in E. coli. We decided to study this enzyme and its expression further in WT and the t1 mutant strains in epidermis and nervous tissue. To our knowledge, this is the first Drosophila-expressed study of this protein. Moreover, it is the first study suggesting different tissue-specific expression/processing of the Tan protein.