Fig. 3.
Collagen, but not CVX, requires α2β1 to fully stimulate Rap1 in human platelets.
Washed human platelets were treated with control buffer, 10 μg/mL control IgG1, or 10 μg/mL of the α2-blocking mAb P1E6 for 15 minutes and then stimulated with either fibrillar type I collagen (Col, 50 μg/mL, left panel, middle, right lanes) or CVX (250 ng/mL, right panel, middle, right lanes) for 1 minute. The presence of active Rap1 was determined as described in Figure 1. Note that the inclusion of P1E6 reduced collagen- but not CVX-mediated Rap1 activation. These results were confirmed in 3 separate experiments.
