Figure 3. Individual DCRD peptides expressed separately from IQV are unable to induce CMI.
(A) PCRD and DCRD tagged with fluorescent proteins were coexpressed with α1DS as separate peptides. The presence of both YFP-PCRD and CFP-DCRD peptides in the same cell was confirmed under a fluorescence microscope (Figure 3—figure supplement 1). Under normal [apoCaM] in cells, no CMI effect was observed from ICa trace exhibiting CDI similarly as α1DS control, confirmed by comparable SCa values and indistinguishable r50 profiles. (B and C) Experiments and analyses were performed in normal [apoCaM] similarly as (A), except that only YFP-PCRD (B) or only YFP-DCRD (C) was expressed with α1DS channels. Both resulted into strong CDI, with SCa and r50 indistinguishable from α1DS control. (D−F) When free [apoCaM] was substantially reduced by overexpressing BSCaMIQ (apoCaM buffers), the above three cases in (A−C) were re-examined. Exemplar ICa traces exhibited strong CDI as quantified by SCa values and r50 profiles, similarly as the control group of α1DS in low [apoCaM] (semitransparent line in red).
Figure 3—figure supplement 1. To confirm the presence of both PCRD and DCRD peptides in single cells.
Figure 3—figure supplement 2. PCRD and DCRD as separate peptides are unable to inhibit VGA.
