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Multiple PIP 2 binding sites in Kir2.1 inwardly rectifying potassium channels
Author(s) -
Soom Malle,
Schönherr Roland,
Kubo Yoshihiro,
Kirsch Cornelia,
Klinger Reinhard,
Heinemann Stefan H.
Publication year - 2001
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(01)02136-6
Subject(s) - binding site , chemistry , potassium channel , biophysics , inward rectifier potassium ion channel , point mutation , stereochemistry , biochemistry , mutation , ion channel , biology , receptor , gene
Inwardly rectifying potassium channels require binding of phosphatidylinositol‐4,5‐bisphosphate (PIP 2 ) 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 PIP 2 containing liposomes. Mutations in the first site, which abolished channel activity, reduced PIP 2 binding of this fragment but not of the complete C‐terminus. Point mutations in the third site also reduced both, channel activity and PIP 2 binding of this segment. The relevance of the third PIP 2 binding site provides a basis for the understanding of constitutively active Kir2 channels.