Fig. 5.

Comparison of CaM kinase calmodulin-binding affinities. (A) Interactions between bait (calmodulin) and two prey molecules (CaMKK1 and CaMKIIα) were monitored in a single cell using ECLIPSE: ** and *** indicate the first endosomal localizations of CaMKK1 and CaMKIIα, respectively. (B) CaMKK1 and CaMKIIα exhibit distinct responses to elevated Ca²⁺ levels. (C) Interaction rates between calmodulin and CaM kinases (CaMKIIα and CaMKK1) at various concentrations of ionomycin in HeLa cells. Interactions were measured by ECLIPSE assay. The addition of ionomycin was considered to be time = 0 min. RFU were normalized against the fluorescence before induction (n = 5). Abbreviations: R, mCherry; IM, ionomycin.