Auto-phosphorylation of a voltage-gated K channel controls non-associative learning

Here, we characterize a new K channel-kinase complex that operates in the metazoan Caenorhabditis elegans to control learning behaviour. This channel is composed of a pore-forming subunit, dubbed KHT-1 (73 homology to human Kv3.1), and the accessory subunit MPS-1, which shows kinase activity. Genetic, biochemical and electrophysiological evidence show that KHT-1 and MPS-1 form a complex in vitro and in native mechanosensory PlM neurons, and that KHT-1 is a substrate for the kinase activity of MPS-1. Behavioural analysis further shows that the kinase activity of MPS-1 is specifically required for habituation to repetitive mechanical stimulation. Thus, worms bearing an inactive MPS-1 variant (D178N) respond normally to touch on the body but do not habituate to repetitive mechanical stimulation such as tapping on the side of the Petri dish. Hence, the phosphorylation status of KHT-1-MPS-1 seems to be linked to distinct behavioural responses. In the non-phosphorylated state the channel is necessary for the normal function of the touch neurons. In the auto-phosphorylated state the channel acts to induce neuronal adaptation to mechanical stimulation. Taken together, these data establish a new mechanism of dynamic regulation of electrical signalling in the nervous system.