Annotated protein:Calpain-1 catalytic subunit (EC 3.4.22.52) (Calcium-activated neutral proteinase 1) (CANP 1) (Calpain mu-type) (Calpain-1 large subunit) (Micromolar-calpain) (muCANP). Gene symbol: CAPN1. Taxonomy: Rattus norvegicus (Rat). Uniprot ID: P97571
antibody wiki:
SynGO gene info:SynGO data @ CAPN1
Ontology domain:Cellular Component
SynGO term:presynapse (GO:0098793)
Annotated paper:Perlmutter LS, et al. "The ultrastructural localization of calcium-activated protease "calpain" in rat brain" Synapse. 1988;2(1):79-88 PMID:2843999
Figure(s):Figure 6c
Annotation description:Figure 1: the antibody recognized only one polypeptide specific for calpain 1 on SDS-PAGE from rat brain. No signal was found for calpain 2

Figure 2: the antibody was effective in blocking the activity of brain calpain 1, but was about ten-fold less potent to inhibit brain calpain 2 activity.

Figure 7: immunoEM for calpain 1 in rat brains showed localization to postsynaptic densities and spines.

"Fewer immunoreactive axons were observed within the gray matter, and the staining of presynaptic terminals was relatively rare (see Fig. 6C). Where present, reaction product was deposited within the spaces between the synaptic vesicles"

Furthermore, calpain 1 was observed in dendrites (Fig. 6), axons (Fig. 5), cell bodies (Fig. 4), mitochondria (Fig. 4, 5B), glia (Fig. 3).
Evidence tracking, Biological System:Intact tissue
Evidence tracking, Protein Targeting:Antibody (detection)
Evidence tracking, Experiment Assay:Electron Microscopy
Annotator(s):Frank Koopmans (ORCID:0000-0002-4973-5732)
Guus Smit (ORCID:0000-0002-2286-1587)
Matthijs Verhage (ORCID:0000-0002-2514-0216)
Lab:Department of Functional Genomics, Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Vrije Universiteit Amsterdam, 1081 HV Amsterdam, The Netherlands
SynGO annotation ID:4741
Dataset release (version):20231201
View annotation as GO-CAM model:Gene Ontology