Activation of IP3 receptors requires an endogenous 1-8-14 calmodulin-binding motif.

dc.creatorSun, Yi
dc.creatorRossi, Ana M
dc.creatorRahman, Taufiq
dc.creatorTaylor, Colin W
dc.date2021-01-05T00:30:10Z
dc.date2021-01-05T00:30:10Z
dc.date2013-01-01
dc.date.accessioned2026-08-03T04:41:28Z
dc.descriptionBinding of IP3 (inositol 1,4,5-trisphosphate) to the IP3-binding core (residues 224-604) of IP3Rs (IP3 receptors) initiates opening of these ubiquitous intracellular Ca2+ channels. The mechanisms are unresolved, but require conformational changes to pass through the suppressor domain (residues 1-223). A calmodulin-binding peptide derived from myosin light chain kinase uncouples these events. We identified a similar conserved 1-8-14 calmodulin-binding motif within the suppressor domain of IP3R1 and, using peptides and mutagenesis, we demonstrate that it is essential for IP3R activation, whether assessed by IP3-evoked Ca2+ release or patch-clamp recoding of nuclear IP3R. Mimetic peptides specifically inhibit activation of IP3R by uncoupling the IP3-binding core from the suppressor domain. Mutations of key hydrophobic residues within the endogenous 1-8-14 motif mimic the peptides. Our results show that an endogenous 1-8-14 motif mediates conformational changes that are essential for IP3R activation. The inhibitory effects of calmodulin and related proteins may result from disruption of this essential interaction.
dc.formatPrint
dc.formatapplication/pdf
dc.identifier0264-6021
dc.identifierhttps://www.repository.cam.ac.uk/handle/1810/315666
dc.identifier10.17863/CAM.62780
dc.identifier1470-8728
dc.identifier.urihttps://repo.dare.co.zw/handle/123456789/192597
dc.languageeng
dc.languageeng
dc.publisherPortland Press
dc.publisherhttps://doi.org/10.1042/bj20121034
dc.rightsAttribution 4.0 International
dc.rightshttps://creativecommons.org/licenses/by/4.0/
dc.subjectAmino Acid Motifs
dc.subjectAmino Acid Sequence
dc.subjectAnimals
dc.subjectBinding Sites
dc.subjectCalmodulin
dc.subjectCattle
dc.subjectCell Line
dc.subjectInositol 1,4,5-Trisphosphate Receptors
dc.subjectMolecular Sequence Data
dc.subjectProtein Binding
dc.subjectProtein Conformation
dc.subjectRats
dc.titleActivation of IP3 receptors requires an endogenous 1-8-14 calmodulin-binding motif.
dc.typeArticle

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