FIGURE 3.

Key PKA targets downstream of β-AR activation in ventricular myocytes, their timing, and functional consequences

PKA phosphorylates multiple target proteins in different domains [red hexagons (P)] at Ca²⁺, Na⁺, and K⁺ channels, SR Ca-ATPase and Na/K-ATPase (ATP), and myofilaments (TPNI, MyBP-C, and titin). Each site may be selectively tuned (both timing and kinetics) to optimize the orchestrated and integrated fight-or-flight response activated by the sympathetic nervous system. Table lists list tentative estimate of timing (numbers) and possibly strength, and related to Ca²⁺ handling (blue) or myofilament (brown).