CD41

CD41 (also known as GPIIb) is a protein that in humans is encoded by the ITGA2B gene. It is a member of the integrin family of proteins, which are important for cell adhesion and signal transduction.

Structure

CD41 is a large, transmembrane glycoprotein that is found on the surface of platelets, megakaryocytes, and some hematopoietic stem cells. It is composed of two subunits: a heavy chain (GPIIb) and a light chain (GPIIIa), which are linked by a disulfide bond. The heavy chain contains the extracellular domain, which is responsible for binding to fibrinogen and other ligands.

Function

CD41 plays a crucial role in the process of platelet aggregation and thrombus formation. It binds to fibrinogen, von Willebrand factor, fibronectin, and vitronectin, facilitating platelet-platelet and platelet-endothelium interactions. This binding is mediated by the RGD sequence in these ligands.

In addition to its role in platelet aggregation, CD41 is also involved in cell signaling, cell migration, and angiogenesis. It can activate various intracellular signaling pathways, leading to changes in cell behavior.

Clinical significance

Mutations in the ITGA2B gene can lead to Glanzmann's thrombasthenia, a rare bleeding disorder characterized by the inability of platelets to aggregate and form a clot. Patients with this condition have prolonged bleeding times and are at risk for severe bleeding episodes.

See also

• Integrin
• Platelet
• Glanzmann's thrombasthenia