1. The Actin Microfilament System Actin was identified more than 50 years ago as an essential element of the force generating apparatus of muscle cells (1, 2). Together with myosin, tropomyosin, and a large number of other proteins, actin filaments constitute sarcomeres, which are ordered serially along contractile myofibrils (3, 4). In the mid 1960s, […]
2. Signal Transduction and Restructuring of the Actin Microfilament System Cell surface receptors continuously monitor the extracellular milieu and pass signals to the cytoplasm by generating second messengers of various kinds which either stimulate or inhibit the activity in the microfilament system. Addition of growth factors to serum-starved cultured cells causes the immediate outgrowth of […]