by using new methods for permeabilizing smooth muscle fibers , which retain the function of receptors and signal transduction systems , we now provide direct evidence that the activation of g protein by norepinephrine or guanosine 5'-0- ( 3-triphosphate ) ( gtp-gamma-s ) , nonhydrolyzable gtp analogue , enhances myofilament sensitivity to ca2+ .
C0037083
signal transduction systems
C0086376
g protein