Fig. 4.
A1 domain of VWF interaction with GPIb does not induce tyrosine phosphorylation of FcRγ chain, Syk, and PLCγ2.
In the presence of 6 μg/mL botrocetin, platelets were stimulated with either 20 μg/mL A1 domain of VWF or 10 μg/mL VWF for the indicated time periods (seconds), respectively. The platelets were processed for precipitation with GST-Syk-SH2 (A), or for immunoprecipitation with anti-Syk (B) and anti-PLCγ2 (C) antibodies. Precipitated proteins were separated by SDS-PAGE and analyzed with an antiphosphotyrosine MoAb (pY; A, B-C upper panels). The membranes were then stripped and reprobed for Syk and PLCγ2 using the corresponding antibodies (B-C, lower panels).