How platelets work in the blood clotting process

Protein ubiquitination downstream of the GPVI collagen receptor in human platelets

Platelets are small circulating cells in the blood that clump together when blood clots after an injury, to prevent excessive bleeding. But platelets are also involved in forming clots in arteries, which can lead to heart attacks and strokes. For platelets to clump together and form a blood clot, they must become ‘activated’. When this happens, some proteins inside the platelets become chemically altered and signal to other platelets to stick together. Scientists recently found that this alteration can be due to a small protein called ubiquitin that sticks to the platelet-protein and either alters the way it works, or ‘marks’ it for destruction – a process called ‘ubiquitination’. Dr Catherine Pears and colleagues have been awarded a grant to generate a list of proteins within platelets that have been altered by ubiquitin. They will use newly available drugs that prevent ubiquitination to see if the drugs have an effect on platelet clumping, and if platelets can ultimately be controlled using these drugs. This project will reveal new proteins involved in the blood clotting process and may lead to new ways to treat heart disease and bleeding disorders.