ITGA2B

ITGA2B Full Name

integrin, alpha 2b (platelet glycoprotein IIb of IIb/IIIa complex, antigen CD41)

ITGA2B Introduction

Integrin alpha-IIb (ITGA2B) is a transmembrane adhesion receptor subunit encoded by the ITGA2B gene and commonly referred to by cluster of differentiation marker CD41. It belongs to the integrin family of heterodimeric cell surface proteins, which pair an alpha chain with a beta chain to form functional receptors involved in cell-matrix and cell-cell interactions. The alpha-IIb chain undergoes proteolytic processing to generate disulfide-linked heavy and light chains that associate with the beta-3 (β3) subunit to form the integrin αIIbβ3 complex, also known as the platelet fibrinogen receptor. This complex is predominantly expressed on platelets and megakaryocytes and mediates binding to multiple extracellular ligands including fibrinogen, fibronectin, vitronectin, plasminogen, thrombospondin and von Willebrand factor, recognizing RGD sequences in these substrates and facilitating adhesion functions central to hemostasis.

Figure 1. This image illustrates the molecular structure and functional mechanism of the Integrin αIIbβ3 complex (also known as the platelet fibrinogen receptor), formed by the association of ITGA2B (CD41) and ITGB3 (CD61).

Functionally, the αIIbβ3 integrin is a key effector of platelet aggregation and clot formation. Upon platelet activation, conformational changes in αIIbβ3 allow high-affinity binding of soluble fibrinogen, enabling cross-linking between adjacent platelets and formation of the platelet plug that physically seals sites of vascular injury. This receptor also participates in bidirectional signaling across the platelet membrane, influencing cytoskeletal rearrangement, granule secretion, and interactions with other cells and matrix components during clot stabilization and wound healing. Beyond classical hemostatic roles, emerging studies suggest that ITGA2B expression and signaling may modulate inflammatory responses and tissue remodeling, with aberrant levels linked to altered cytokine production and impacts on cardiac structure under hypoxic stress.

Clinically, mutations or functional defects in ITGA2B or its partner β3 subunit lead to bleeding disorders, most notably Glanzmann thrombasthenia, an autosomal recessive platelet function defect characterized by impaired platelet aggregation, diminished clot retraction, and mucocutaneous bleeding of varying severity. Over 30 disease-causing mutations in ITGA2B have been identified that disrupt αIIbβ3 expression or function, underscoring its essential role in coagulation. Beyond inherited bleeding phenotypes, ITGA2B expression patterns and integrin signaling have been investigated in contexts such as cardiovascular disease, thrombosis, and cancer, where integrins contribute to cell adhesion, migration, and extracellular matrix interactions that can influence disease progression and therapeutic responses.

Alternate Names for ITGA2B

ITGA2B; integrin, alpha 2b (platelet glycoprotein IIb of IIb/IIIa complex, antigen CD41); GT; GTA; CD41; GP2B; HPA3; CD41B; GPIIb; BDPLT2

• 1. Nurden AT, Pillois X. ITGA2B and ITGB3 gene mutations associated with Glanzmann thrombasthenia. Platelets. 2018, 29(1):98-101.