Referenced in: none

Automatically associated channels: Kir2.1 , Kir2.3

Title: Multiple PIP2 binding sites in Kir2.1 inwardly rectifying potassium channels.

Authors: M Soom, R Schönherr, Y Kubo, C Kirsch, R Klinger, S H Heinemann

Journal, date & volume: FEBS Lett., 2001 Feb 9 , 490, 49-53

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/11172809

Abstract
Inwardly rectifying potassium channels require binding of phosphatidylinositol-4,5-bisphosphate (PIP2) for channel activity. Three independent sites (aa 175-206, aa 207-246, aa 324-365) were located in the C-terminal domain of Kir2.1 channels by assaying the binding of overlapping fragments to PIP2 containing liposomes. Mutations in the first site, which abolished channel activity, reduced PIP2 binding of this fragment but not of the complete C-terminus. Point mutations in the third site also reduced both, channel activity and PIP2 binding of this segment. The relevance of the third PIP2 binding site provides a basis for the understanding of constitutively active Kir2 channels.