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¡¡¡¡    Transient changes in intracellular Ca²⁺ concentrations regulate diverse cellular functions. Cellular responses are often dependent on changes in amplitude, duration, and frequency of these Ca²⁺ transients. These changes in signal parameters can be integrated by Ca²⁺/calmodulin-dependent autophosphorylation of dodecameric CaMKII holoenzymes at Thr286. The Thr286 autophosphorylated CaMKII retains Ca²⁺-independent protein kinase activity that prolongs cellular signaling after cessation of Ca²⁺ transients. The Colbran lab has focused on testing an over-arching hypothesis that multiple CaMKII-associated proteins (CaMKAPs) target CaMKII holoenzymes to distinct subcellular domains, providing an added layer of regulation by exposing them to different Ca²⁺ signals and counter-regulatory protein phosphatases. Moreover, CaMKII holoenzymes can be co-localized with different substrates to mediate distinct downstream signals. Several different classes of CaMKAP have been characterized, which interact with CaMKII holoenzymes by distinct mechanisms and exert unique functional effects. Interestingly, several CaMKAPs target CaMKII holoenzymes to plasma membrane ligand- or voltage-gated calcium channels. I will present data showing that the interactions of CaMKII with some of these CaMKAPs are important for feedback regulation of these channels, as well as for downstream signaling in different contexts.