Aims: Alcohol abuse poses a serious public health problem, and repeated ingestion can produce tolerance, leading to dependence and addiction. However, the mechanisms underlying alcohol tolerance and addiction are not fully understood. Drosophilae have been employed as a suitable model to study the molecular mechanisms underlying ethanol tolerance. JWA, a newly identified microtubule-binding protein, was shown to regulate cell stress responses, transportation of intracellular excitatory amino acids, and the MAPK signal transduction pathway. The JWA mouse homologue addicsin, was postulated to play a role in the development of morphine tolerance and dependence. This study was designed to determine whether JWA participates in ethanol tolerance in Drosophila.
Methods: The jwa homologous gene in Drosophila, CG10373 (djwa) was cloned and the anti-djwa and cDNA-djwa transgenic fly strains, which exhibit a reduced and elevated djwa expression respectively were constructed. Real-time PCR was used to measure the djwa levels in the resulting fly strains. Rapid tolerance experiments including inebriation exposure and recovering assay were employed.
Results: The djwa and the human jwa genes share a significant sequence similarity. Their genomic nucleotide and deduced amino acid sequence identities are 41.4% and 53.6%, respectively. In inebriation tests, the wild type w(1118) flies and the cDNA-djwa flies acquired ethanol tolerance after several exposures whereas the anti-djwa flies did not.
Conclusions: The JWA genes are evolutionarily conserved. The djwa function is required for acquiring ethanol tolerance in Drosophila. JWA is likely a novel molecule playing an important role in ethanol tolerance and drug addiction. Our results present a new direction for research related to alcohol tolerance and addiction.