 The paper reviews the mechanisms that regulate the turnover of contractile proteins and organelles in muscle tissue, and discusses how impairments in these mechanisms can contribute to muscle atrophy. It also highlights the importance of understanding how protein synthesis and degradation are co-ordinately regulated by signalling pathways influenced by mechanical stress, physical activity, and nutrient availability for the prevention and treatment of muscle atrophy in various diseases. This article was authored by Paulo Bonoldo and Marcos André.