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Full-Text Articles in Medicine and Health Sciences
Conformational Motions And Ligand-Binding Underlying Gating And Regulation In Ip3r Channel, Guizhen Fan, Mariah R Baker, Lara E Terry, Vikas Arige, Muyuan Chen, Alexander B Seryshev, Matthew L Baker, Steven J Ludtke, David I Yule, Irina I Serysheva
Conformational Motions And Ligand-Binding Underlying Gating And Regulation In Ip3r Channel, Guizhen Fan, Mariah R Baker, Lara E Terry, Vikas Arige, Muyuan Chen, Alexander B Seryshev, Matthew L Baker, Steven J Ludtke, David I Yule, Irina I Serysheva
Journal Articles
Inositol-1,4,5-trisphosphate receptors (IP3Rs) are activated by IP3 and Ca2+ and their gating is regulated by various intracellular messengers that finely tune the channel activity. Here, using single particle cryo-EM analysis we determined 3D structures of the nanodisc-reconstituted IP3R1 channel in two ligand-bound states. These structures provide unprecedented details governing binding of IP3, Ca2+ and ATP, revealing conformational changes that couple ligand-binding to channel opening. Using a deep-learning approach and 3D variability analysis we extracted molecular motions of the key protein domains from cryo-EM density data. We find that IP3 binding relies upon intrinsic flexibility of the ARM2 domain in the …
Functional Determination Of Calcium-Binding Sites Required For The Activation Of Inositol 1,4,5-Trisphosphate Receptors, Vikas Arige, Lara E Terry, Larry E Wagner, Sundeep Malik, Mariah R Baker, Guizhen Fan, Suresh K Joseph, Irina I Serysheva, David I Yule
Functional Determination Of Calcium-Binding Sites Required For The Activation Of Inositol 1,4,5-Trisphosphate Receptors, Vikas Arige, Lara E Terry, Larry E Wagner, Sundeep Malik, Mariah R Baker, Guizhen Fan, Suresh K Joseph, Irina I Serysheva, David I Yule
Journal Articles
Inositol 1,4,5-trisphosphate receptors (IP3Rs) initiate a diverse array of physiological responses by carefully orchestrating intracellular calcium (Ca2+) signals in response to various external cues. Notably, IP3R channel activity is determined by several obligatory factors, including IP3, Ca2+, and ATP. The critical basic amino acid residues in the N-terminal IP3-binding core (IBC) region that facilitate IP3 binding are well characterized. In contrast, the residues conferring regulation by Ca2+ have yet to be ascertained. Using comparative structural analysis of Ca2+-binding sites identified in two main families of intracellular Ca2+-release channels, ryanodine receptors (RyRs) and IP3Rs, we identified putative acidic residues coordinating Ca2+ …