Lysosomal serine protease with tripeptidyl-peptidase I activity. May act as a non-specific lysosomal peptidase which generates tripeptides from the breakdown products produced by lysosomal proteinases. Requires substrates with an unsubstituted N-terminus. Defects in TPP1 are the cause of neuronal ceroid lipofuscinosis type 2 (CLN2). A form of neuronal ceroid lipofuscinosis. Neuronal ceroid lipofuscinoses are progressive neurodegenerative, lysosomal storage diseases characterized by intracellular accumulation of autofluorescent liposomal material, and clinically by seizures, dementia, visual loss, and/or cerebral atrophy. The lipopigment pattern seen most often in CLN2 consists of curvilinear profiles. Belongs to the peptidase S53 family. 2 isoforms of the human protein are produced by alternative splicing. Note: This description may include information from UniProtKB.
Protein type: Secreted; Mitochondrial; Protease; Secreted, signal peptide; EC 18.104.22.168
Molecular Function: peptidase activity; tripeptidyl-peptidase activity; protein binding; serine-type peptidase activity; metal ion binding; serine-type endopeptidase activity; endopeptidase activity; peptide binding
Biological Process: cell death; nervous system development; cellular protein metabolic process; unfolded protein response, activation of signaling protein activity; epithelial cell differentiation; lysosome organization and biogenesis; unfolded protein response; peptide catabolic process; protein catabolic process; lipid metabolic process; neuromuscular process controlling balance; proteolysis; bone resorption
SS: The number of records in which this modification site was determined using site-specific methods. SS methods include amino acid sequencing, site-directed mutagenesis, modification site-specific antibodies, specific MS strategies, etc.