Inhibition of cell surface ruffling and fluid-phase pinocytosis by microinjection of anti-ras antibodies into living cells.

Fibroblasts transformed by ras oncogenes display enhanced cell surface ruffling and fluid-phase pinocytotic activities. Microinjection of antibodies that specifically bind the ras proteins into these cells results in the inhibition of these two surface activities. The possible underlying biochemical basis of the influence of the ras proteins on membrane ruffling and pinocytosis and the potential relationship of these two biological activities to membrane signal transduction are discussed.