Genomic and proteomic approaches offer distinct advantages in the search for novel ethanol sites of action because they allow large numbers of elements (RNA transcripts and/or proteins) to be examined simultaneously in an unbiased fashion. INIA West laboratories have performed numerous gene expression studies utilizing both Affymetrix and cDNA microarraysto identify genes that differ in animals bred for high and low ethanol drinking, as well as, those that change in response ethanol administration using drosophila, rodent, and human models of alcoholism. In a significant collaborative effort, INIA West investigators recently worked to consolidate these different microarray experiments and prioritize genes and functionally related groups of genes that were changed significantly in response to ethanol administration. The results of these studies indicate that ethanol alters the expression pattern of a number of genes known to be involved in synapse-related protein trafficking and synaptic transmission. Proteins encoded by the genes are important for a variety of synaptic events including neurotransmitter vesicle transport and targeting (synapsin, syntaxin, dynamin, and synaptotagmin), motor proteins involved in trafficking and targeting of synaptic proteins (kinesin family proteins (KIFs)), and scaffolding proteins (homer and discs-large homolog 2). Interaction proteomics will be used to identify novel protein complexes associated with each of these target proteins in C57BL/6 mice. The effect of excessive ethanol consumption (dependence model of withdrawal-induced drinking (WID)) on these protein complexes will be determined. The overall hypothesis is that excessive ethanol consumption alters protein complexes important for normal trafficking and targeting of proteins involved in synaptic transmission. The resulting changes in trafficking, targeting, and synaptic function underlie ethanol-related phenotypes.
