ITGB1

Description

The ITGB1 (integrin subunit beta 1) is a protein-coding gene located on chromosome 10.

Integrin beta-1 (ITGB1), also known as CD29, is a cell surface receptor that in humans is encoded by the ITGB1 gene. This integrin associates with integrin alpha 1 and integrin alpha 2 to form integrin complexes which function as collagen receptors. It also forms dimers with integrin alpha 3 to form integrin receptors for netrin 1 and reelin. These and other integrin beta 1 complexes have been historically known as very late activation (VLA) antigens. Integrin beta 1 is expressed as at least four different isoforms. In cardiac muscle and skeletal muscle, the integrin beta-1D isoform is specifically expressed, and localizes to costameres, where it aids in the lateral force transmission from the Z-discs to the extracellular matrix. Abnormal levels of integrin beta-1D have been found in limb girdle muscular dystrophy and polyneuropathy.

== Structure == Integrin beta-1 can exist as different isoforms via alternative splicing. Six alternatively spliced variants have been found for this gene which encode five proteins with alternate C-termini. Integrin receptors exist as heterodimers, and greater than 20 different integrin heterodimeric receptors have been described.

ITGB1, also known as CD29, is a cell surface receptor encoded by the ITGB1 gene. It forms complexes with integrin alpha subunits, acting as a receptor for various extracellular matrix proteins and cell surface ligands. ITGB1 complexes with alpha-1, alpha-2, alpha-10, and alpha-11 to bind collagen. ITGB1 complexes with alpha-1, alpha-2, alpha-3, alpha-4, alpha-5, alpha-8, alpha-10, alpha-11, and alpha-V to bind fibronectin. Specifically, alpha-4/beta-1 binds to CS-1 and CS-5 regions of fibronectin. Alpha-5/beta-1 binds fibrinogen. ITGB1 complexes with alpha-1, alpha-2, alpha-6, and alpha-7 to bind laminin. Alpha-6/beta-1 is involved in sperm-egg fusion. Alpha-4/beta-1 binds to VCAM1, recognizing the sequence Q-I-D-S. Alpha-9/beta-1 binds to VCAM1, cytotactin, and osteopontin, recognizing A-E-I-D-G-I-E-L in cytotactin. Alpha-3/beta-1 binds to epiligrin, thrombospondin, and CSPG4, potentially mediating CSPG4-stimulated endothelial cell migration. Alpha-V/beta-1 binds to vitronectin. ITGB1 complexes generally recognize the R-G-D sequence in ligands. Alpha-7/beta-1 regulates cell adhesion and laminin matrix deposition. ITGB1 promotes endothelial cell motility and angiogenesis, aids in osteoblast compaction, and may upregulate PKC activity. ITGB1 plays a role in cytokinesis. Alpha-3/beta-1 facilitates invadopodia formation and matrix degradation. ITGA4:ITGB1 binds to fractalkine (CX3CL1) and may act as a coreceptor in fractalkine signaling. ITGA4:ITGB1 and ITGA5:ITGB1 bind to PLA2G2A, inducing conformational changes and enhanced ligand binding. ITGA5:ITGB1 is a receptor for fibrillin-1 (FBN1) and fibronectin (FN1). ITGA5:ITGB1 is a receptor for IL1B and CD40LG. ITGB1 is important for myoblast differentiation and fusion. ITGA9:ITGB1 may contribute to SVEP1-mediated myoblast cell adhesion. ITGA9:ITGB1 and ITGA4:ITGB1 interact with SVEP1 to inhibit vasoconstriction. ITGB1 isoform 5 displaces isoform 1 in striated muscles.

ITGB1 is also known as CD29, FNRB, GPIIA, MDF2, MSK12, VLA-BETA, VLAB.

Associated Diseases

WES Whole Exome Sequencing