Reactome | Platelet degranulation

Platelet degranulation

Stable Identifier

R-HSA-114608

Type

Pathway

Species

Homo sapiens

ReviewStatus

5/5

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Platelets function as exocytotic cells, secreting a plethora of effector molecules at sites of vascular injury. Platelets contain a number of distinguishable storage granules including alpha granules, dense granules and lysosomes. On activation platelets release a variety of proteins, largely from storage granules but also as the result of apparent cell lysis. These act in an autocrine or paracrine fashion to modulate cell signaling.

Alpha granules contain mainly polypeptides such as fibrinogen, von Willebrand factor, growth factors and protease inhibitors that that supplement thrombin generation at the site of injury. Dense granules contain small molecules, particularly adenosine diphosphate (ADP), adenosine triphosphate (ATP), serotonin and calcium, all recruit platelets to the site of injury. The molecular mechanism which facilitates granule release involves soluble NSF attachment protein receptors (SNAREs), which assemble into complexes to form a universal membrane fusion apparatus. Although all cells use SNAREs for membrane fusion, different cells possess different SNARE isoforms. Platelets and chromaffin cells use many of the same chaperone proteins to regulate SNARE-mediated secretion (Fitch-Tewfik & Flaumenhaft 2013).

Literature References

PubMed ID	Title	Journal	Year
	Platelets in thrombotic and non-thrombotic disorders. Page, CP, Vermylen, J, Gresele, P, Fuster, V		2002
14630798	Characterization of the proteins released from activated platelets leads to localization of novel platelet proteins in human atherosclerotic lesions McRedmond, JP, Toomey, S, Fitzgerald, DJ, Cahill, DJ, Belton, O, Maguire, PB, Kislinger, T, Emili, A, Coppinger, JA, Cagney, G	Blood	2004