Date of Award
M.S. in Biological Science
University of Mississippi
Although the effects of ethanol on presynaptic activity have been studied, the molecular mechanisms and the changes in gene expression which are responsible for inducing ethanol tolerance are unclear. Munc13-1 is an active-zone protein that is essential for presynaptic vesicle fusion. This protein interacts with vesicle fusion machinery at presynaptic active zones in the mammalian brain. The C1 domain of Munc13-1 binds diacylglycerol (DAG), which helps membrane localization of this protein and promotes vesicle fusion, facilitating synaptic vesicle release. Previously, it was shown that ethanol binds to the C1 domain of Munc13-1 in vitro at concentrations below 100 mM (Das et al., 2013). The ethanol binding inhibits DAG binding to the Munc13-1 C1 domain at a concentration as low as 25 mM (Xu et al., 2017). Previously, it was also found that Dunc13, which is the Drosophila homolog of the mammalian Munc13-1, haploinsufficiency shohigh-level resistance to the sedative effect of ethanol. This result was initially unexpected since overall Dunc13 activity is lower in the Dunc13 haploinsufficient flies. We predicted this would sensitize the flies to further Dunc13 inhibition by ethanol, leading to more rapid sedation. One possible mechanism is that reducing Dunc13 activity genetically, through the expression of Dunc13 RNAi transgenes or mutation, will mimic the molecular changes that accompany ethanol tolerance. Here we shothat flies with chronically reduced Dunc13 activity produced significantly more rapid tolerance to the sedative effects of ethanol than wild type control flies. In addition, we analyzed the genes which were differentially expressed after ethanol treatment. Here we shothe genes which might be responsible for inducing rapid tolerance and the patterns of transcriptional changes were largely different between Dunc13 haploinsufficiency group and ethanol-treated group.
Wachi, Yusuke, "The Role Of Dunc13 In Ethanol Tolerance" (2019). Electronic Theses and Dissertations. 1947.