Muscle protein breakdown (MPB)

Muscle protein breakdown refers to the physiological process in which muscle proteins are degraded, principally via the ubiquitin-proteasome pathway, autophagic-lysosomal system, and calpain proteases. The purpose of this breakdown is to recycle amino acids for energy, adaptation, and remodeling in conditions such as exercise, fasting, and disease. Dysregulation of the process is implicated in muscle atrophy syndromes, but it is not a singular pharmacological target. Instead, therapies are designed to modulate its regulatory components, such as E3 ubiquitin ligases (e.g., MuRF1, Atrogin-1), proteasomes, or myostatin signaling, each of which may serve as a discrete target within this broader process.

Other names

Muscle protein catabolismMPBmuscle proteolysismuscle protein degradation

Inhibition of ubiquitin-proteasome pathway, Myostatin/activin receptor inhibition, Suppression of autophagy, Anti-inflammatory signaling