Biochemical characterization of a dual reconstituted system responsive to fusicoccin

Abstract

Recent studies on the mode of action of fusicoccin (FC) have shed some light on the molecular events associated with the perception of FC at the plasma membrane (PM). Several years ago it was suggested that FC affects characteristic physiological processes through the activation of the PM H+-ATPase (Marre, 1979). The circumstantial evidence for this activation, obtained from in vivo experiments, has found support from in vitro systems. In fact, after some controversial reports, some recent papers have reported on the stimulation of proton translocation by FC in microsomal vesicles from radish (Rasi-Caldogno and Pugliarello, 1985; Rasi-Caldogno et al., 1986; De Michelis et al., 1989), as well as of ATP hydrolisis in plasmalemma-rich vesicles from Vicia faba (Blum et al., 1988) and in microsomes from cell-suspension cultures of Corydalis sempervirens(Schulz et al., 1990).