RnoEX0045048 @ rn6

Comparison of the integrin ITGA6 isoform alpha6AX1X2 (contains cassette exon X2 (HsaEX0032368)) with the alpha6AX1 isoform (lacks exon X2) using similarly transfected K562 cells showed no obvious differences between the alternative extracellular alpha6A isoforms with respect to ligand specificity and activation-dependency of ligand binding. After treatment with the anti-beta1 stimulatory antibody TS2/16, both the alpha6AX1beta1 and alpha6AX1X2beta1 integrin variants mediated cell adhesion to EHS tumor laminin (laminin-1), kalinin (laminin-5), human placental (laminin-2 and -4) and bovine kidney laminins. In contrast, the alpha6AX1beta4 and alpha6AX1X2beta4 integrins also mediated cell adhesion to laminin and kalinin without stimulation. Furthermore, the different transfectants did not differ in their ability to spread on kalinin. The presented data indicate that the X2 region in alpha6 is not involved in defining ligand specificity or affinity.