tailieunhanh - Báo cáo khoa học: Activation of PMCA by calmodulin or ethanol in plasma membrane vesicles from rat brain involves dissociation of the acetylated tubulin/PMCA complex

We have recently shown that acetylated tubulin interacts with plasma mem-brane Na + ,K + -ATPase and inhibits its enzyme activity in several types of cells. H + -ATPase of Saccharomyces cerevisiae is similarly inhibited by interaction with acetylated tubulin. | ỊFEBS Journal Activation of PMCA by calmodulin or ethanol in plasma membrane vesicles from rat brain involves dissociation of the acetylated tubulin PMCA complex Noelia E. Monesterolo1 Veronica S. Santander1 Alexis N. Campetelli1 Carlos A. Arce2 Hector S. Barra2 and Cesar H. Casale1 1 Departamento de Biologia Molecular Universidad Nacionalde Rio Cuarto Argentina 2 Centro de Investigaciones en Quimica Biologica de Cordoba CIQUIBIC Universidad Nacionalde Cordoba Argentina Keywords acetylated tubulin calmodulin ethanol plasma membrane Ca2 -ATPase P-type ATPase Correspondence C. H. Casale Departamento de Biologia Molecular Facultad de Ciencias Exactas Fisico-Quimicas y Naturales Universidad Nacionalde Rio Cuarto Rio Cuarto 5800 Coi rdoba Argentina Fax 54 358 467 6232 Tel 54 358 467 6422 E-mail ccasale@ Received 11 April2008 revised 6 May 2008 accepted 12 May 2008 doi We have recently shown that acetylated tubulin interacts with plasma membrane Na K -ATPase and inhibits its enzyme activity in several types of cells. H -ATPase of Saccharomyces cerevisiae is similarly inhibited by interaction with acetylated tubulin. The activities of both these ATPases are restored upon dissociation of the acetylated tubulin ATPase complex. Here we report that in plasma membrane vesicles isolated from brain syn-aptosomes another P-type ATPase plasma membrane Ca2 -ATPase PMCA undergoes enzyme activity regulation by its association dissocia-tion with acetylated tubulin. The presence of acetylated tubulin PMCA complex in membrane vesicles was demonstrated by analyzing the behavior of acetylated tubulin in a detergent partition and by immunoprecipitation experiments. PMCA is known to be stimulated by ethanol and calmodulin at physiological concentrations. We found that treatment of plasma membrane vesicles with these reagents induced dissociation of the complex with a concomitant restoration of enzyme activity. Conversely incubation of vesicles