AKAP 18 α and γ have opposing effects on insulin release in INS-1E cells

A-kinase anchoring proteins (AKAPs) are known to compartmentalise protein kinase(s) to discrete cellular locations. Here we show that silencing of AKAP 18 α or γ expression results in decreased or increased glucose-stimulated insulin secretion in INS-1E cells. Glucose stimulates AKAP 18 α and inhibits AKAP 18 γ mRNA expressions while palmitate markedly reduces AKAP 18 α expression. Human growth hormone (GH) stimulates AKAP 18 α expression and attenuates palmitate-induced suppression of AKAP 18 α mRNA level. The roles of AKAP 18 α and γ in mediating insulin release are consistent with their respective regulations by glucose.