CD41; integrin alpha-IIb; platelet membrane glycoprotein IIb (ITGA2B, GP2B, ITGAB)

Function

• associated with integrin beta-3 (integrin alpha-2b/beta-3)

Structure

• composed of an heavy & a light chain linked by a disulfide bond
• belongs to the integrin alpha chain family
• contains 7 FG-GAP repeats

Compartment

membrane

Alternative splicing

named isoforms=3

Expression

• isoform 1 & isoform 2 were identified in platelets & megakaryocytes, but not in reticulocytes or in Jurkat & U937 white blood cell line
• isoform 3 is expressed by leukemia, prostate adenocarcinoma & melanoma cells but not by platelets or normal prostate or breast epithelial cells

Pathology

• polymorphism:
  • position 874 is associated with platelet-specific alloantigen HPA-3/BAK/LEK
  • HPA-3A/BAK(A)/LEK(A) has Ile-874 & HPA-3B/BAK(B)/LEK(B) has Ser-874
  • HPA-3B is involved in neonatal alloimmune thrombocytopenia
• defects in ITGA2B are a cause of Glanzmann thrombasthenia
• expressed in AML-M7

Laboratory

• HPA-3 type in blood

More general terms

• integrin-alpha
• glycoprotein
• CD antigen

Component of

• integrin alpha-2b/beta-3

Database

• OMIM: https://mirror.omim.org/entry/273800
• OMIM: https://mirror.omim.org/entry/607759
• UniProt: http://www.uniprot.org/uniprot/P08514.html