Aluminium fluoride associates with the small guanine nucleotide binding proteins

Abstract
AlF4 has long been known to associate with and activate the GDP‐bound alpha subunits of heterotrimeric G‐proteins. Recently the small guanine nucleotide binding protein Ras has also been shown to associate with AlF4 in the presence of stoichiometric amounts of its TPase ctivating rotein (GAP). Here we present the isolation of a stable Ras·GDP·AlF4 ·GAP ternary complex by gel filtration. In addition, we generalise the association of AlF4 with the small GTP‐binding proteins by demonstrating ternary complex formation for the Cdc42, Rap and Ran proteins in the presence of their respective GAP proteins.