Figure 1.

Q567H is located in the extracellular S1–S2 loop of domain II in the Ca_V1.3 α₁ subunit. A, schematic of Ca_V1.3 α₁ subunit with the mutation indicated (star). B, alignment of amino acids corresponding to this extracellular loop flanked by portions of S1 and S2. Box indicates conserved glutamine that is substituted with histidine because of the mutation. Capital letters indicate amino acids that are conserved in all sequences. Lowercase letters indicate conserved amino acids in at least six sequences.