CAPN1

Calpain-1, encoded by CAPN1 and also known as mu-calpain, is a calcium-dependent cysteine protease activated by micromolar Ca²⁺ concentrations. It cleaves diverse substrates (cytoskeletal proteins, signaling molecules, enzymes) to regulate cell migration, cytoskeleton remodeling, and signal transduction via pathways like PI3K/Akt and MAPK, maintaining cellular homeostasis.
Dysregulation of CAPN1 links to neurodegenerative disorders (e.g., Alzheimer’s disease, where it cleaves tau protein) and cardiovascular diseases (e.g., myocardial ischemia-reperfusion injury). Calpain inhibitors such as calpeptin and PD150606 are under development, though most remain in preclinical or early clinical stages due to specificity and off-target effect challenges.