- Top of page
- A new model of platelet alpha-granule biology: distinct subpopulations of alpha-granules
- How are distinct subpopulations of alpha-granules established in platelets?
- Transport and packaging of alpha granules into assembling platelets
- Selective release of alpha-granules
- Can we use new platelet alpha-granule biology to make ‘designer platelets?’
- Final thoughts
- Disclosure of Conflict of Interests
Summary. One of the main functions of blood platelets is to secrete a variety of substances that can modify a developing thrombus, regulate the growth of the vasculature, promote wound repair, and contribute to cell-adhesive events. A majority of this vast array of secreted proteins are stored in alpha-granules. Until recently, it was assumed that platelets contained one homogeneous population of alpha-granules that undergo complete de-granulation during platelet activation. This review focuses on the mechanisms of alpha-granule biogenesis and secretion, with a particular emphasis on recent findings that clearly demonstrate that platelets contain distinct subpopulations of alpha-granules that undergo differential release during activation. We consider the implications of this new paradigm of platelet secretion, discuss mechanisms of alpha-granule biogenesis, and review the molecular basis of transport and delivery of alpha-granules to assembling platelets.