Cyr61 induction by Xa is independent of thrombin but mediated by PAR-1 activation.

Serum-starved HeLa cells were stimulated for 90 minutes with 20 nM thrombin, 50 nM Xa, or 0.5 U/mL Ecarin. Where indicated, the cells were incubated with monoclonal antibodies to PAR-1 (10 μg/mL ATAP2, 25 μg/mL WEDE15) or 100 nM hirudin for 20 minutes before the addition of the proteases. Total RNA was purified, and transcripts forCyr61 and GAPDH (G3) as a loading control were detected by Northern blotting.