Mechanism of MgATP-induced SUR1/Kir6.2 activation

Objective: SUR1/Kir6.2 channels are of key importance in insulin release. MgATP critically controls these channels by interaction with SUR1. Aims: In this study we focussed on further elucidating the molecular basis of this interaction. Methods: For this purpose we constructed a series of SUR1 mutations. These mutants were transiently coexpressed in COS-cells and effects of nucleotides on channel activity were tested using the inside-out configuration of the patch-clamp technique. Results: MgATP induced strong reversible activation of SUR1/Kir6.2-G334D channels being half-maximally effective at 310µM. In wild-ty…