Cookies on this website
We use cookies to ensure that we give you the best experience on our website. If you click 'Continue' we'll assume that you are happy to receive all cookies and you won't see this message again. Click 'Find out more' for information on how to change your cookie settings.

The inositol 1,4,5-trisphosphate receptor (InsP(3)R) is activated by InsP(3) binding to amino-terminal ligand binding domain (InsP(3)R-N). Recently we reported functional coupling of phosphatidylinositol (4, 5)-bisphosphate (PIP(2)) to the InsP(3)R. Specific binding of PIP(2) to InsP(3)R-N domain was postulated as a part of the InsP(3)R-PIP(2) functional coupling model. Here we utilized bacterially expressed and purified InsP(3)R-N domain to characterize its binding specificity for InsP(3), Adenophostin A (AdA) and the water-soluble PIP(2) analog dioctanoyl-(4,5)PIP(2) (ShPIP(2)). Obtained data led us to conclude that specific InsP(3), AdA, and ShPIP(2) binding sites are located within the InsP(3)R-N domain, that the extra receptor binding element responsible for enhanced binding of AdA is an integral part of the InsP(3)R-N domain, that ShPIP(2) is able to displace InsP(3) from the InsP(3)R-N, but InsP(3) or AdA is unable to completely displace ShPIP(2). These results support the InsP(3)R-PIP(2) functional coupling model and provide novel insights into InsP(3)R ligand specificity.

Original publication

DOI

10.1006/mcbr.2000.0208

Type

Journal article

Journal

Mol Cell Biol Res Commun

Publication Date

03/2000

Volume

3

Pages

153 - 158

Keywords

Adenosine, Animals, Binding Sites, Calcium Channels, Inositol 1,4,5-Trisphosphate Receptors, Ligands, Phosphatidylinositol 4,5-Diphosphate, Rats, Receptors, Cytoplasmic and Nuclear, Recombinant Proteins