I propose to examine the inhibition of apoptosis by the lysophospholipid mediator, lysophosphatidic acid (LPA), via stimulation of specific members a family of GPCRs, known as the endothelial cell differentiation gene (EDG) receptors. The true cellular function of EDG receptors has yet to be clearly established. However, numerous studies have demonstrated the ability of LPA to elicit various biological responses. The goal of this study is to determine the initial components involved in the mechanism used by lysophospholipids to mediate the inhibition of apoptosis. Ultimately, the information obtained in this study will allow us to establish the pathway utilized by lysophospholipds to mediate this inhibition, and promote the design of pharmaceutical agents that could attenuate this inhibitory effect.