ACTIVATION OF H+-ATPASE BY GLUCOSE IN SACCHAROMYCES CEREVISIAE INVOLVES A MEMBRANE SERINE PROTEASE

CAMPETELLI, A; MONESTROLO, N; PREVITALI, G; SANTANDER, V; AMAIDEN, R; ARCE, C; VALDEZ TAUBAS, J; CASALE, C

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2013 vol. 1830 p. 3593 - 3593

ackground: Glucose induces H+-ATPase activation in Saccharomyces cerevisiae. Our previous study showed that (i) S. cerevisiae plasma membrane H+-ATPase forms a complex with acetylated tubulin (AcTub), resulting in inhibition of the enzyme activity; (ii) exogenous glucose addition results in the dissociation of the complex and recovery of the enzyme activity. Methods: We used classic biochemical and molecular biology tools in order to identify the key components in the mechanism that leads to H+-ATPase activation after glucose treatment. Results: We demonstrate that glucose-induced dissociation of the complex is due to pH-dependent activation of a protease that hydrolyzes membrane tubulin. Biochemical analysis identified a serine protease with a kDa of 35–40 and an isoelectric point between 8 and 9. Analysis of several knockout yeast strains led to the detection of Lpx1p as the serine protease responsible of tubulin proteolysis. When lpx1Δ cells were treated with glucose, tubu