The molecular mechanism by which PIP(2) opens the intracellular G-loop gate of a Kir3.1 channel.

ABSTRACT: Inwardly rectifying potassium (Kir) channels are characterized by a long pore comprised of continuous transmembrane and cytosolic portions. A high-resolution structure of a Kir3.1 chimera revealed the presence of the cytosolic (G-loop) gate captured in the closed or open conformations. Here, we conducted molecular-dynamics simulations of these two channel states in the presence and absence of phosphatidylinositol bisphosphate (PIP(2)), a phospholipid that is known to gate Kir channels. Simulations of the closed state with PIP(2) revealed an intermediate state between the closed and open conformations involving direct transient interactions with PIP(2), as well as a network of transitional inter- and intrasubunit interactions. Key elements in the G-loop gating transition involved a PIP(2)-d

SUBMITTER: Meng XY 

PROVIDER: S-EPMC3341553 | biostudies-literature | 2012 May

REPOSITORIES: biostudies-literature