Fig. 1: Biochemical characterizations of the CaV1.2-JPH interaction.
a Domain organizations of CaV1.2 and JPH2. JPH2 MORN-Helix can directly interact with a stretch of residues (JBM) at the C-terminal cytoplasmic tails of CaV1.1 and CaV1.2. b SEC-MALS experiments showing the binding profile of CaV1.2 JBM to mouse JPH2 NT (top) or JPH2 MORN-Helix (bottom). The fitted molecular weights are expressed as best-fitted values ± SE. SE standard error. c ITC-based measurements quantifying the binding affinities between Trx-CaV1.2 JBM and MBP-JPH2 NT (left) or MBP-JPH2 MORN-Helix (right). The Kd values in this panel and throughout the manuscript are presented as best-fit values ± fitting errors. d ITC-derived dissociation constants for interactions between CaV1.2 JBM and various JPH proteins. Results corresponding to the JPH2 MORN-Helix are highlighted in red. The black asterisk indicates that the value represents the mean of three independent experiments, expressed as Mean ± SD. e Strep pull-down assay using cell lysates showing the interaction between Strep-JPH1/2/3 NT fragments and GFP-tagged full-length CaV1.2. f ITC-based measurement of the interactions between CaV1.2 JBM and JPH disease-related mutants. Results corresponding to the S165F mutant are highlighted in red. The black asterisk indicates that the value represents the mean of three independent experiments, expressed as Mean ± SD. g Structural superposition of the JPH2/CaV1.1 JBM complex (PDB ID: 7RXQ). Disease-related residues are highlighted with red spheres (E85, S165, and A399).
