This mechanism of subtractive isoform reorganization (i.e. the loss of sensitive isoforms) is possible because only some of the BK α-subunit mRNAs within a neuron contain 3’UTRs with a miR-9 Recognition Element (MRE). It is only this subset of BK message that is downregulated by alcohol exposure (Figure 3b). Moreover, this mechanism results in the regulation of additional miR-9 targets relevant to alcohol abuse. Thus, one can envision a concept of miRNA master switches, activated by alcohol, coordinating an integrated and dynamic response pattern among a number of downstream targets.
