RasGRP, a Ras Guanyl Nucleotide- Releasing protein with Calcium-and Diacylglycerol-Binding Motifs

摘要

RasGRP, a guanyl nucleotide-releasing protein for the small guanosine triphosphatase Ras, was characterized. Besides the catalytic domain, RasGRP has an atypical pair of "EF hands" that bind calcium and a diacylglycerol (DAG)-bindign domain. RasGRP activated Ras and caused transformation in fibroblasts. A DAG analog caused sustained activation of Fas-Erk signaling and changes in cell morphology. Signaling was associ- ated with partitioning of RasGRP protein into the membrane fraction.