Calcium/calmodulin-dependent protein kinase II regulates Caenorhabditis elegans locomotion in concert with a G(o)/G(q) signaling network.

Caenorhabditis elegans locomotion is a complex behavior generated by a defined set of motor neurons and interneurons. Genetic analysis shows that UNC-43, the C. elegans Ca(2+)/calmodulin protein kinase II (CaMKII), controls locomotion rate. Elevated UNC-43 activity, from a gain-of-function mutation, causes severely lethargic locomotion, presumably by inappropriate phosphorylation of targets. In a genetic screen for suppressors of this phenotype, we identified multiple alleles of four genes in a G(o)/G(q) G-protein signaling network, which has been shown to regulate synaptic activity via diacylglycerol. Mutations in goa-1, dgk-1, eat-16, or eat-11 strongly or completely suppressed unc-43(gf) lethargy, but affected other mutants with reduced locomotion only weakly. We conclude that CaMKII and G(o)/G(q) pathways act in concert to regulate synaptic activity, perhaps through a direct interaction between CaMKII and G(o).