Hendrikus Granzier, PhD, studies the mechanisms whereby the giant filamentous protein titin (the largest protein known) influence muscle structure and function. His lab has shown that titin functions as a molecular spring that mediates acute responses to changing pathophysiological states of the heart. They also study the role of titin in cardiac disease, using mouse models with specific modifications in the titin gene, including deciphering the mechanisms that are responsible for gender differences in diastolic dysfunction. An additional focus of Dr. Granzier’s lab is on nebulin, a major muscle protein that causes a severe skeletal muscle disease in humans. Based on previous work, they hypothesize that nebulin is a determinant of calcium sensitivity of contractile force. To test this and other concepts, he uses a nebulin knockout approach in the mouse. Research is multi-faceted and uses cutting-edge techniques at levels ranging across the single molecule, single cell, muscle, and the intact heart. His research group is diverse and has brought together individuals from several continents with expertise ranging from physics and chemistry to cell biology and physiology.