ITA2B_HUMAN
Source:
PM23856902
BSc_CH
Marked as 'Integral membrane protein'
Confidence:
medium (present in either hRBCD or BSc_CH or PM22954596)
Search PubMed for
(RBC AND this entry)
Gene names:
ITGA2B
, GP2B, ITGAB
Protein names and data:
ITA2B_HUMAN
, Integrin alpha-IIb
, GPalpha IIb; GPIIb; Platelet membrane glycoprotein IIb; CD41; Integrin alpha-IIb heavy chain; Integrin alpha-IIb light chain, form 1; Integrin alpha-IIb light chain, form 2; Flags: Precursor
Lenght: 1039 a.a.
Mass: 113377 Da
fasta formatted sequence
Function:
Integrin alpha-IIb/beta-3 is a receptor for fibronectin, fibrinogen, plasminogen, prothrombin, thrombospondin and vitronectin. It recognizes the sequence R-G-D in a wide array of ligands. It recognizes the sequence H-H-L-G-G-G-A-K-Q-A-G-D-V in fibrinogen gamma chain. Following activation integrin alpha- IIb/beta-3 brings about platelet/platelet interaction through binding of soluble fibrinogen. This step leads to rapid platelet aggregation which physically plugs ruptured endothelial cell surface.
Disease:
( OMIM:
187800
273800
607759
)
Glanzmann thrombasthenia (GT) [MIM:273800]: A common inherited disease of platelet aggregation. It is characterized by mucocutaneous bleeding of mild-to-moderate severity. GT has been classified clinically into types I and II. In type I, platelets show absence of the glycoprotein IIb-IIIa complexes at their surface and lack fibrinogen and clot retraction capability. In type II, the platelets express the GPIIb-IIIa complex at reduced levels, have detectable amounts of fibrinogen, and have low or moderate clot retraction capability. Note=The disease is caused by mutations affecting the gene represented in this entry. Bleeding disorder, platelet-type 16 (BDPLT16) [MIM:187800]: An autosomal dominant form of congenital macrothrombocytopenia associated with platelet anisocytosis. It is a disorder of platelet production. Affected individuals may have no or only mildly increased bleeding tendency. In vitro studies show mild platelet functional abnormalities. Note=The disease is caused by mutations affecting the gene represented in this entry.
Cellular location:
Membrane; Single-pass type I membrane protein.
Tissue specificity:
Isoform 1 and isoform 2 were identified in platelets and megakaryocytes, but not in reticulocytes or in Jurkat and U-937 white blood cell line. Isoform 3 is expressed by leukemia, prostate adenocarcinoma and melanoma cells but not by platelets or normal prostate or breast epithelial cells.
Genetic variants
Position 874 is associated with platelet-specific alloantigen HPA-3/BAK/LEK. HPA-3A/BAK(A)/LEK(A) has Ile-874 and HPA-3B/BAK(B)/LEK(B) has Ser-874. HPA-3B is involved in neonatal alloimmune thrombocytopenia (NAIT or NATP).
40 - 40
T -> I (in dbSNP:rs5915). VAR_014176
5915
86 - 86
L -> P (in GT; cells co-transfected with mutated alpha-IIb and wild-type beta-3 scarcely expressed the alpha-IIb/beta-3 complex). VAR_030445
139 - 139
A -> V (in GT). VAR_030446
161 - 161
C -> W (in GT). VAR_030447
174 - 174
Y -> H (in GT; abolishes the binding function of alpha-IIb/beta-3 for soluble ligands without disturbing alpha-IIb/ beta-3 expression; functional defect is likely caused by its allosteric effect rather than by a defect in the ligand- binding site itself). VAR_030448
176 - 176
P -> A (in GT; impairs surface expression of alpha-IIb/beta-3 and abrogates ligand binding to the activated integrin). VAR_009885
176 - 176
P -> L (in GT; impairs surface expression of alpha-IIb/beta-3). VAR_009886
202 - 202
F -> C (in GT; associated with abrogation of alpha-IIb/beta-3 complex formation). VAR_030449
207 - 207
T -> I (in GT). VAR_030450
214 - 214
L -> P (in GT; disrupts the structural conformation and the ligand binding properties of the heterodimeric complex; in addition the mutation appears to confer susceptibility to proteolysis). VAR_030451
222 - 222
F -> L (in GT). VAR_030452
267 - 267
G -> E (in GT). VAR_030453
273 - 273
G -> D (in GT; alters the heterodimer conformation thus impairing their intracellular transport). VAR_003979
313 - 313
G -> A (in dbSNP:rs1126554). VAR_054820
1126554
320 - 320
F -> S (in GT; type I; impairs surface expression of alpha-IIb/beta-3). VAR_009887
329 - 329
V -> F (in GT; expression of mutant subunit alpha-IIb/bet-3 is 28% of control; mutant pro-alpha-IIb subunit is retained in the endoplasmic reticulum). VAR_030454
355 - 355
E -> K (in GT; type I; impairs surface expression of alpha-IIb/beta-3). VAR_009888
358 - 358
R -> H (in GT; type II). VAR_003980
380 - 380
G -> D (in GT). VAR_030455
405 - 405
I -> T (in GT; expression of mutant subunit alpha-IIb/bet-3 is 11% of control; mutant pro-alpha-IIb subunit is retained in the endoplasmic reticulum). VAR_030456
412 - 412
G -> R (in GT). VAR_030457
449 - 449
G -> D (in GT; type I). VAR_003981
456 - 457
Missing (in GT; alteres the conformation of heterodimers such that they were neither recognized by the heterodimer- specific antibody A2A9 nor able to undergo further intracellular processing or transport to the cell surface). VAR_030458
581 - 581
A -> D (in GT). VAR_030459
596 - 596
I -> T (in GT; type I). VAR_030460
649 - 649
V -> L (in dbSNP:rs7207402). VAR_054821
7207402
705 - 705
C -> R (in GT; type II; the rate of subunit maturation and the surface exposure of ghlycoprotein IIb/beta-3 are strongly reduced). VAR_030461
752 - 752
L -> V (in GT). VAR_030462
755 - 755
R -> P (in GT). VAR_030463
778 - 778
Q -> P (in GT; type II). VAR_003982
847 - 847
L -> P (in GT). VAR_030464
874 - 874
I -> S (alloantigen HPA-3B; dbSNP:rs5911). VAR_003983
5911
934 - 934
V -> F (in GT; the mutation prevented normal ITGA2B/ITGB3 complex expression on the cell surface consistent with a severe type 1 phenotype). VAR_069917
943 - 943
P -> L (in GT; marked reduction in the rate of surface expression). VAR_030465
957 - 957
S -> L (in GT; the mutation prevented normal ITGA2B/ITGB3 complex expression on the cell surface consistent with a severe type 1 phenotype; the mutation may interfere with correct folding of the protein). VAR_069918
968 - 968
Y -> N (in dbSNP:rs5914). VAR_014177
5914
982 - 982
V -> M (in GT; much reduced surface expression of alpha-IIb/beta-3 and a block in the maturation of pro-alpha- IIb). VAR_030466
989 - 989
A -> T (in dbSNP:rs78165611). VAR_030467
78165611
1026 - 1026
R -> Q (in GT and BDPLT16; results in low surface expression of the mutant protein). VAR_030468
1026 - 1026
R -> W (in BDPLT16; results in abnormal membrane ruffling and cytoplasmic protrusions as well as defective proplatelet formation). VAR_069919
Database cross-references
UniProt:
P08514
Ensembl:
ENST00000262407
Ensembl:
ENST00000353281
MIM:
187800
MIM:
273800
MIM:
607759
neXtProt:
NX_P08514
Antibodypedia:
P08514
(may not find the protein thus also not any antibody)
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