Capn1 Protein is an important component in the neurobiology of neurodegenerative diseases. This page provides detailed information about its structure, function, and role in disease processes.
Gene: CAPN1 [1]
UniProt: P07384 [2]
Molecular Weight: ~82 kDa (catalytic subunit) [3]
Subcellular Localization: Cytosol, membrane-associated [4]
Protein Family: Calpain family, cysteine proteases [5]
CAPN1 (Calpain 1), also known as μ-calpain or μ-calcium-activated neutral protease (μCANP), is a calcium-dependent cysteine protease that mediates limited proteolysis of various substrates. Calpain 1 is heterodimeric, consisting of a catalytic large subunit (CAPN1, ~80 kDa) and a regulatory small subunit (CAPNS1, ~28 kDa). The protease is ubiquitously expressed and plays critical roles in both normal cellular processes including signal transduction, cell cycle progression, and synaptic plasticity, as well as pathological processes including apoptosis and neurodegeneration. CAPN1 is activated by micromolar calcium concentrations and requires calmodulin for full activity. Unlike calpain 2 (m-calpain), calpain 1 is activated at lower calcium concentrations, making it particularly relevant in physiological signaling. [6]
Calpain 1 is a heterodimer composed of: [7]
The protease contains:
Calpain 1 catalyzes limited, non-destructive proteolysis:
Key neuronal substrates include:
CAPN1 is widely expressed in:
Expression is particularly high in regions with high synaptic activity.
The study of Capn1 Protein has evolved significantly over the past decades. Research in this area has revealed important insights into the underlying mechanisms of neurodegeneration and continues to drive therapeutic development.
Historical context and key discoveries in this field have shaped our current understanding and will continue to guide future research directions.
Liu J, Liu MC, Wang KKW. Calpain in CNS neurons and diseases: a target for neuroprotection. Expert Opinion on Therapeutic Targets. 2008. ↩︎
Baudry M, Bi X. Calpain-1 and Alzheimer's disease: mechanisms and therapeutic potential. ACS Chemical Neuroscience. 2013. ↩︎
Yamashima T. Reconsider Alzheimer's disease by targeting 'calpain-cdk5 system' in the perspective of its heterogeneity. Ageing Research Reviews. 2019. ↩︎
Wang Y, et al. Calpain activation and proteolytic cleavage of alpha-synuclein. Journal of Neurochemistry. 2018. ↩︎
Czogalla A, Sikorski AF. Spectrin and calpain: a 'target' and 'executor' in neurodegeneration? Molecular Neurobiology. Molecular Neurobiology. 2019. ↩︎
Ray SK. Currently available calpain inhibitors for treating stroke. Advances in Neurobiology. 2014. ↩︎
Huang Y, Wang KKW. The calpain family and human disease. Trends in Molecular Medicine. 2001. ↩︎