IN SEARCH OF A FUNCTION FOR THE RAS-LIKE GTPASE RAP1

Rap1 (Krev-1) is a small GTPase first identified as a transformation s uppressor of K-ras. This GTPase is very similar to Ras, particularly i n the effector region, but its function is still elusive, Recent progr ess in the search for Rap1 function has come from the development of a novel assay to measure Rap1 activation. Using this assay activation o f Rap1 was observed in human platelets and neutrophils after stimulati on with various agonists, We speculate that Rapl plays a role in one o f the specialised functions of these cells. (C) 1997 Federation of Eur opean Biochemical Societies.