Signaling Receptors on Platelets and Megakaryocytes

Although the body of knowledge is far from complete, much has been learned about the receptors that enable circulating platelets to become activated at sites of vascular injury. A variety of approaches have been used to acquire this information, many of which are described elsewhere in this book. Far less is known about the receptors that are expressed on megakaryocytes, some of which play specific roles in megakaryocyte development and some of which mirror those that will subsequently be found on platelets. Our intent in this chapter is to provide a receptor-centric overview of platelet activation, followed by a very brief consideration of receptor function in megakaryocytes and megakaryoblastic cell lines. (Our apologies in advance to the authors of the many excellent studies that we have not cited in our effort to be brief.)