Histamine is a neurotransmitter used in the fruit fly, Drosophila melanogaster, and is synthesized by the enzyme histidine decarboxylase (HDC). Immunocytochemical data indicates that histamine is localized to the nerve terminals in the photoreceptor cell layer where it is released as a neurotransmitter. The localization and the native size of the HDC protein have not been established however. If HDC were found close to the synaptic region, it would suggest that histamine synthesis occurs very close to the location where it is released. Likewise, the size of the protein would determine whether the HDC protein undergoes proteolysis, as occurs in other species and would allow purification of the protein in the future. Transgenic flies that bear a functional Hdc gene with an internal 6xHis epitope tag were studied. These flies were used in preparing protein extracts and tissue samples for Western blotting and immunolocalization, respectively. Western blotting results using a penta-HIS antibody detect a unique protein in flies bearing the 6xHis-HDC-Sac1 transgene. Immunocytochemical localization in tissue is also in progress and initial results will be reported.
Faculty Mentors: Martin Burg, Biomedical Sciences & Debra Burg, Biomedical Science