This study describes the isolation of a receptor that regulates the aggregation of blood platelets and is already the target of some of the best antithrombotic drugs currently available. Thus, the work is relevant to many fields that include basic science research, clinical medicine, and biotechnology.

When we examined where the receptor gene was expressed, we only found the corresponding messenger RNA in platelets and glial cells of the central nervous system.

The evidence that this receptor is utilized by such a selective population of cells makes it an extremely attractive drug target.

It has been known for years that extracellular nucleotides like adenosine diphosphate (ADP) will cause blood platelets to aggregate. This action of ADP was thought to be mediated by a receptor on platelets that could reduce cyclic adenosine monophosphate (cAMP) levels within the cell. Additionally, the antithrombotic drugs clopidogrel and ticlopidine were hypothesized to inhibit thrombus formation in patients by inactivating this same receptor protein on platelets. Thus, we designed an assay system that would allow us to screen through messenger RNAs from platelets and isolate the one that encoded the receptor protein of interest.

We have isolated a receptor protein from blood platelets that is the target of drugs which inhibit the formation of clots in blood vessels. Examination of this protein will help us understand how platelets aggregate and design better drugs to prevent heart attacks and strokes.