|CD49a||ITGA1 (integrin α1), VLA-1α chain (very late antigen α1 chain), α-1 integrin chain|
|Molecule Type||Antigen Expression||Molecular Weight|
Min / Max
|Non-lineage Restricted Molecule|
Type 1 glycoprotein
|200 / 200|
210 / 210
|CD49a is expressed on monocytes, megakaryocytes, activated T cells, cultured neuronal cells, melanoma cells, mesenchymal cells, smooth muscle cells, fibroblasts, hepatocytes, microvascular endothelium and at low levels on resting T cells. Its expression on T cells is increased upon prolonged stimulation in vitro. It is also found at increased levels on T lymphocytes in synovial joints of patients with rheumatoid arthritis and on melanoma cells. However, its expression is reduced following phytohemagglutinin stimulation. CD49a expression on NK cells is upregulated by IL-2.|
|MOLECULAR FAMILY NAME: Belongs to the integrin a chain family.|
CD49a is a single-pass type-1 1152 aa glycoprotein. It contains a 28 aa signal peptide, a large 206 aa N-terminal extracellular domain which contains an I-domain and 26 potential glycosylation sites, a transmembrane domain and a short 15 aa C-terminal cytoplasmic domain. All integrin α chains have a conserved sequence found in the cytoplasmic domain immediately following the transmembrane domain (FYWS)-(RK)-x-G-F-F-x-R that may be the motif involved in heterodimer formation. It noncovalently associated with the CD29 molecule to form the VLA-1 (a1/β1) integrin subunit.
POST-TRANSCRIPTIONAL MODIFICATION: No information.
POST-TRANSLATIONAL MODIFICATION: No information.
|LIGANDS AND MOLECULES ASSOCIATED WITH CD49a|
CD49a/CD29 binds laminin-1 and type-5 collagen through different binding sites.
|CD49a is an cell-cell adhesion molecule. CD49a acts as an adhesion receptor for collagen IV and laminin-1. The integrin CD49a/CD29 on choriocarcinoma and melanoma cells binds collagen and the E1 fragment of laminin. CD49a is involved in leukocyte migration into tissues. However, collagen binding is not mediated by CD49a/CD29 on cultured T lymphocytes. In vitro studies have shown enhancement of effector T cell proliferation and cytokine production when bound to collagen via CD49a. In vivo CD49a modulates effector inflammatory responses. An inserted von Willebrand factor type 1 domain is thought to be involved in collagen binding.|
BIOCHEMICAL ACTIVITY: No information.
DISEASE RELEVANCE AND FUNCTION OF CD49a IN INTACT ANIMAL
CD49 is involved in embryo development. CD40a plays a role in inflammatory responses and fibrosis.
PROTEIN AND DNA ELEMENTS WHICH REGULATE TRANSCRIPTION OF CD49a: No information.
SUBSTRATES: No information.
ENZYMES WHICH MODIFY CD49a: No information.
Database accession numbers
Revised June 25, 2008