The BK_Ca (slo) channel regulates the cardiac function of Drosophila

The large conductance, calcium, and voltage-active potassium channels (BK_Ca) were originally discovered in Drosophila melanogaster as slowpoke (slo). They are extensively characterized in fly models as ion channels for their roles in neurological and muscular function, as well as aging. BK_Ca is known to modulate cardiac rhythm and is localized to the mitochondria. Activation of mitochondrial BK_Ca causes cardioprotection from ischemia-reperfusion injury, possibly via modulating mitochondrial function in adult animal models. However, the role of BK_Ca in cardiac function is not well-characterized, partially due to its localization to the plasma membrane as well as intracellular membranes and the wide array of cells present in mammalian hearts. Here we demonstrate for the first time a direct role for BK_Ca in cardiac function and cardioprotection from IR injury using the Drosophila model system. We have also discovered that the BK_Ca channel plays a role in the functioning of aging hearts. Our study establishes the presence of BK_Ca in the fly heart and ascertains its role in aging heart function.