PYK2/CAK beta represents a redox-sensitive tyrosine kinase in vascular smooth muscle cells

In vascular smooth muscle cells (VSMCs), the focal adhesion kinase-related tyrosine kinase PYK2/CAK beta is activated by vascular mitogens, Because re active oxygen species (ROS) are assumed to mediate mitogenic signals by the se agonists, we examined the possible link between ROS and PYK2 in cultured rat VSMCs. Here we present several lines of evidence showing that PYK2 is activated by ROS in VSMCs. The inhibitory effect of an antioxidant, N-acety l-cysteine, on PYK2 activation by its specific agonists further suggests th e pivotal role of PYK2 in vascular remodeling associated with enhanced ROS production. (C) 2000 Academic Press.