The present invention relates to screening methods that make use of Myosin Phosphatase-Rho interacting Protein (M-RIP) for the identification of novel therapeutics for hypertension and hypertensive conditions. Also disclosed are methods for treating or preventing hypertension or hypertensive conditions by administering to a mammal a therapeutically effective amount of an agent that reduces the level or activity of M-RIP. According to this invention, the agent decreases contractile and increases relaxant effects of smooth muscle cells, ultimately decreasing the systemic blood pressure of a mammal. For example, the agent may reduce binding of M-RIP to myosin phosphatase, RhoA, or both.