1. From the Cardiologie Cellulaire et Moléculaire U-446 INSERM (A.K., V.V., E.B., A.M., R.V.-C.), Université Paris-Sud, Châtenay-Malabry, France; Molecular Physiology and Genetics (M.N.), Slovak Academy of Sciences, Bratislava, Slovak Republic. Present address for A.K. is Department of Pharmacology, University of Tartu, Tartu, Estonia; present address for E.B. is Wellcome Trust Centre for Human Genetics, Oxford, UK.