Recombinant Mouse Integrin alpha 9 beta 1 Protein, CF

Integrin alpha 9 beta 1 is one of twelve integrin family adhesion receptors that share the beta 1 (CD29) subunit (1‑3). It is the non‑covalent heterodimer of 150 kDa alpha 9 and 130 kDa beta 1 type I transmembrane glycoprotein subunits (3). The alpha 9 extracellular domain (ECD) contains an N‑terminal beta ‑propeller structure, followed by domains termed thigh, calf‑1 and calf‑2 (2). The beta 1 ECD contains a vWFA domain, which interacts with the alpha 9 beta ‑propeller to form a binding domain when the dimer is in the active, extended and open conformation. The 1006 amino acid (aa) mouse alpha 9 extracellular domain (ECD) shares 95% and 89% aa sequence identity with rat and human alpha 9, respectively, while the 708 aa mouse beta 1 ECD shares 98% aa identity with rat and 93‑94% with human, bovine, porcine, ovine, canine and feline beta 1. Each subunit has a transmembrane sequence and a short cytoplasmic tail which, for alpha 9, contains binding sites for paxillin and SSAT (spermine/spermidine-N-acetyltransferase) (4, 5). Integrin alpha 9 beta 1 inhibits cell spreading via signaling through paxillin (4). SSAT interaction with alpha 9 beta 1 allows catalysis that lifts spermine/spermidine inhibition of KIR potassium channels, and is shown to enhance cell migration or suppress airway smooth muscle contraction (5, 6). Lymphangiogenic vascular endothelia growth factors VEGF‑C and VEGF‑D are ligands for Integrin alpha 9 beta 1 (7, 8) Genetic deletion of mouse alpha 9 beta 1 results in a fatal chylothorax due to abnormal lymphatic development (9). Integrin alpha 9 beta 1 interacts in cis with G‑CSF R and enhances its signals, contributing to granulopoiesis (10). It also binds VCAM‑1, which promotes neutrophil transendothelial migration and delays apoptosis (11, 12). Other ligands for alpha 9 beta 1 include polydom/SVEP1, tenascin, osteopontin, nerve growth factor, and most members of the ADAM family (13‑16).