14652018 |
Fernandes AR, Durao PJ, Santos PM, Sa-Correia I: Activation and significance of vacuolar H+-ATPase in Saccharomyces cerevisiae adaptation and resistance to the herbicide 2,4-dichlorophenoxyacetic acid. Biochem Biophys Res Commun. 2003 Dec 26;312(4):1317-24. The stimulation of the activity of the H (+)-ATPase present in the vacuolar membrane (V-ATPase) of Saccharomyces cerevisiae is here described in response to a moderate stress induced by 2,4-dichlorophenoxyacetic acid (2,4-D). This in vivo activation (up to 5-fold) took place essentially during the adaptation period, preceding cell division under herbicide stress, in coordination with a marked activation of plasma membrane H (+)-ATPase (PM-ATPase) (up to 30-fold) and the decrease of intracellular and vacuolar pH values, suggesting that activation may be triggered by acidification. Single deletion of VMA1 and genes encoding other V-ATPase subunits led to a more extended period of adaptation and to slower growth under 2,4-D stress. Results suggest that a functional V-ATPase is required to counteract, more rapidly and efficiently, the dissipation of the physiological H (+)-gradient across vacuolar membrane registered during 2,4-D adaptation. |
14(0,0,2,4) |