Role of Thr17 phosphorylation (PTHR17) of phospholamban (PLB) in the mechanical recovery from acidosis.

FERRERO P, SAID M, VALVERDE C, MUNDIÑA-WEILENMANN C, VITTONE L, MATTIAZZI A.

Buenos Aires

Congreso; XII Meeting of the International Society for Heart Research. Latin American; 2003

International Society for Heart Research

Role of Thr17 phosphorylation (PThr17) of phospholamban (PLB) in the mechanical recovery from acidosis P. Ferrero, M. Said, C. Valverde, C. Mundiña-Weilenmann, L. Vittone, A. Mattiazzi. Centro. Inv. Cardiovasc. La Plata, Argentina It was suggested that the mechanical recovery (MR) from acidosis in myocytes requires PLB (DeSantiago et al, Biophys J; 2003). The role of PLB phosphorylation sites on MR was studied in Langendorff perfused rat hearts. After the initial impairment in left ventricular developed pressure (LVDP), +dP/dt and LVDP decay (T) produced by acidosis (high pCO2 a rapid MR (within 3 min) ocurred followed by a slow MR towards a steady state. PThr17 significantly increased at 1-3 min of acidosis and then returned to control values. Time of acidosis 1 min 3 min 10 min +dP/dt (% C) n=7 20,9 ±1,1 36,4±2,0 43,0±2,5 t(Dms of C) n=7 15,9±1,9 8,38±0,8 5,7±1,7 P-Thr17(%)+ n=4 80,3±11,4 78,4±12,3 26,8±10,3 P-Ser16(%)+ n=4 22,1±9,9 22,6±9,5 11,9±4,6 † % maximal-isoproterenol site-specific phosphorylation; C = control values before acidosis. † % maximal-isoproterenol site-specific phosphorylation; C = control values before acidosis. † % maximal-isoproterenol site-specific phosphorylation; C = control values before acidosis. The association of the rapid phase of MR with maximal PTh17 suggests a role of this PLB site in the MR