Jonathan Lytton

The broad subject of investigation in the Lytton laboratory is the control of calcium homeostasis. Calcium ion is a ubiquitous second messenger whose cytoplasmic concentration regulates a host of diverse biological events including muscle contraction, neurotransmitter secretion, hormone signaling, vesicle targeting and cell cycle control. We study proteins that transport calcium across membranes using molecular, biochemical, cellular and physiological techniques to understand structure, function and regulation.A major area of focus concerns a family of K-dependent Na/Ca-exchangers (NCKX) that are abundant in brain neurons, but also expressed selectively in other tissues. The unique roles these exchangers play in physiology is being pursued using recombinant structure-function studies, cell biological analyses, and genetically engineered mice. Our work is currently focused on two of these transporters, NCKX2 and NCKX4. The former appears to play a role in hippocampal plasticity underlying motor learning and working memory consolidation. The latter appears to play a pivotal role in the normal function of brain circuits underlying feeding behaviour and satiety. Current efforts are directed toward understanding the mechanisms that lead from exchanger function to the regulation of these important physiological processes.