James H Morrissey

My lab's research focuses on understanding how the human blood clotting system functions in health (normal hemostasis) and disease (thrombosis). In particular, we conduct biochemical studies aimed at elucidating the underlying mechanisms controlling the complex series of enzyme-activation events that make up the blood clotting cascade, which lead ultimately to the formation of a fibrin clot and activated platelets. Thrombosis is the formation of unwanted blood clots inside arteries and veins, which represents one of the leading causes of disability and death worldwide. For this reason, it is critically important to understand how the the blood coagulation is regulated. My lab's research program is a combination of basic and translational research.

We are currently focusing on the following research questions:
-- How do the serine proteases of the blood clotting system assemble together with specific regulatory proteins on membrane surfaces?
-- These enzyme activation events are thousands of times less active in solution than on membrane surfaces. Why are membranes required for efficient proteolysis by these enzymes? What role do specific phospholipid types play in modulating the activity of blood clotting proteases?
-- We recently discovered that inorganic polyphosphate (secreted from activated platelets and abundant in many microorganisms) is a novel and highly potent modulator of blood clotting and fibrinolysis. It is also proinflammatory. What are the mechanisms by which polyphosphate exerts these biologic activities?