Fig. 4.

Integration of mechanical deformation and chemical signals in striated muscle. The effects of mechanical load and post-translational modification are shown diagrammatically with the resulting protein modifications by the signals for phosphorylation (P), acetylation (Ac), and binding of phospholipid phosphatidylinositol 4,5-bisphosphate (PIP2) to sarcomeric destinations. Mechanical loading alone triggers muscle hypertrophy, as does activation of the chemical signaling pathways alone. The mechanical loading is effective at the subcellular level near to the deformed proteins while the chemical signals is distributed throughout the cells. Thus, both local and whole cell response can be regulated