The Characterization and Identification of Ceramide‐1‐Phosphate Binding Proteins

Abstract

The activation of cytosolic phospholipase A2 α (cPLA2α) has been implicated in atherosclerosis and cerebral ischemia in previous animal models. The sphingolipid metabolite ceramide‐1‐phosphate (C1P) is known to specifically regulate the activation of cPLA2α and has been shown to increase enzymatic activity 5–10 fold through increased membrane residence. We have recently determined the amino acids that are responsible for C1P binding to cPLA2α in vitro and in a cellular system. In addition to heart disease, the conversation of ceramide to C1P has been implicated in cancer and phagocytosis signaling, suggesting that there are unidentified proteins that are regulated by C1P binding in membranes. Using the novel cPLA2α consensus sequence to search the proteome, we have predicted and are currently investigating new C1P binding proteins. Through the characterization of the C1P binding site, we have constructed a novel model for C1P recognition in membranes that deviates from the traditional lipid binding mechanism. This molecular characterization provides great insight into the molecular basis of C1P recognition and selectivity in biological membranes and will significantly increase the molecular basis of C1P binding by proteins. The understanding of this binding site in particular would lay the groundwork for a promising therapy for heart disease.AHA 11PRE7640028 (KEW)NIH T32GM075762 (KEW)