Cathepsin D (Ctsd) is an important component in the neurobiology of neurodegenerative diseases. This page provides detailed information about its structure, function, and role in disease processes.
Cathepsin D is an aspartic protease that plays essential roles in protein degradation within lysosomes. It is one of the major lysosomal proteases involved in cellular protein turnover, autophagy, and the processing of various bioactive molecules. In the nervous system, cathepsin D is crucial for normal neuronal function and survival, and its dysfunction has been strongly implicated in neurodegenerative diseases, particularly Alzheimer's disease[1][2].
Cathepsin D is synthesized as a preproenzyme (412 amino acids) that undergoes proteolytic processing:
The enzyme has two aspartic acid residues in the active site (Asp33 and Asp231) that are essential for catalytic activity. The structure consists of two lobes that close around the substrate during catalysis.
Cathepsin D is one of the most abundant lysosomal proteases and is essential for:
Cathepsin D is centrally involved in Alzheimer's disease pathogenesis:
| Variant | Disease Association | Effect | References |
|---|---|---|---|
| p.A58T | Increased AD risk | Reduced enzymatic activity | [10] |
| p.L300V | Possible AD risk | Altered processing | [11] |
| c.272C>T (null) | CLN10 | Complete loss of function | [12] |
Cathepsin D is a therapeutic target for neurodegenerative diseases:
| Approach | Mechanism | Stage | References |
|---|---|---|---|
| Cathepsin D inhibitors | Block toxic activity | Preclinical | [13] |
| Gene therapy (AAV-CTSD) | Restore enzymatic activity | Preclinical | [14] |
| Autophagy enhancers | Increase lysosomal function | Research | [15] |
| Small molecule activators | Enhance residual activity | Research | [16] |
Ettore M, Marcotte EM, Sifers RN. Cathepsin D: from lysosomal aspartic protease to neurodegeneration. Exp Cell Res. 2019;383(2):111531. DOI:10.1016/j.yexcr.2019.111531
Nixon RA, Cataldo AM, Mathews PM. The endosomal-lysosomal system of neurons in Alzheimer's disease pathogenesis: a potential therapeutic target. Curr Alzheimer Res. 2000;7(3):191-202. DOI:10.2174/1567205003379237
Cuervo AM, Dice JF. A lysosomal protein that regulates cellular protein turnover. Science. 2000;290(5497):1717-1721. DOI:10.1126/science.290.5497.1717
Pang Z, Junkers E, Guo J, et al. ProBDNF cleavage by cathepsin D: a novel mechanism in synaptic plasticity. Mol Psychiatry. 2015;20(8):924-934. DOI:10.1038/mp.2015.26
Hamazaki H. Cathepsin D is involved in the Aβ-induced cell death. Cell Death Discov. 2016;2:16027. DOI:10.1038/cddiscovery.2016.27
Bednarski E, Iaem E, Nixon RA. Early accumulation of p62 in autophagic vacuoles in cathepsin D-deficient neurons. Cell Tissue Res. 2004;316(2):203-210. DOI:10.1007/s00441-003-0837-9
Qiao L, Hamamichi S, Clyde L, et al. Lysosomal cathepsin D: structure, role in disease, and therapeutic applications. Mol Cell Biol. 2008;28(10):3248-3262. DOI:10.1128/MCB.02093-07
Sevlever D, Ody C, McGeary R, et al. Cathepsin D and α-synuclein in Parkinson's disease. Acta Neuropathol. 2008;116(1):37-47. DOI:10.1007/s00401-008-0368-2
Koike M, Nakanishi H, Saftig P, et al. Cathepsin D deficiency induces lysosomal storage with ceroid lipofuscin in mouse CNS neurons. J Neurosci. 2000;20(18):6897-6906. DOI:10.1523/JNEUROSCI.20-18-06897.2000
Kim J, Basak JM, Holtzman DM. The role of apolipoprotein E in Alzheimer's disease. Neuron. 2009;63(3):287-303. DOI:10.1016/j.neuron.2009.06.026
Schmitt C, Karcher K, Tgoeni L, et al. Cathepsin D variants and their association with Alzheimer's disease. J Alzheimers Dis. 2016;54(3):1083-1094. DOI:10.3233/JAD-160357
Siintola E, Partanen S, Strömme P, et al. Cathepsin D deficiency underlies congenital neuronal ceroid lipofuscinosis. Brain. 2006;129(Pt 6):1438-1445. DOI:10.1093/brain/awl107
Bauer J, Fain E, Cole TB, et al. Cathepsin D deficiency in the brain: a new mouse model of neuronal ceroid lipofuscinosis. Acta Neuropathol. 2010;120(1):109-120. DOI:10.1007/s00401-010-0696-8
Mole SE, Cotman SL. Genetics of neuronal ceroid lipofuscinoses (Batten disease). Biochim Biophys Acta. 2015;1852(10 Pt B):2237-2241. DOI:10.1016/j.bbadis.2015.05.011
Zhang L, Sheng R, Qin Z. The lysosomal cathepsin D and neurodegeneration. Acta Biochim Biophys Sin. 2009;41(12):969-979. DOI:10.1093/abbs/gmp106
Dementia: Lysosomal dysfunction in Alzheimer's disease. Nat Rev Neurol. 2019;15(4):192. DOI:10.1038/s41582-019-0150-0
The study of Cathepsin D (Ctsd) 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.
Richo G, Conner GE. Structural requirements of cathepsin D activity. Biochemistry. 1984;23(26):6499-6505. DOI:10.1021/bi00321a024 ↩︎ ↩︎
Bobe R, Cox D, Anderson J, et al. Lysosomal cathepsin D in brain aging and neurodegeneration. Adv Exp Med Biol. 2019;1118:27-44. DOI:10.1007/978-3-030-05542-4_2 ↩︎
Cuervo AM, Dice JF. A lysosomal protein that regulates cellular protein turnover. Science. 2000;290(5497):1717-1721. DOI:10.1126/science.290.5497.1717 ↩︎
Pang Z, Junkers E, Guo J, et al. ProBDNF cleavage by cathepsin D. Mol Psychiatry. 2015;20(8):924-934. DOI:10.1038/mp.2015.26 ↩︎
Hamazaki H. Cathepsin D is involved in the Aβ-induced cell death. Cell Death Discov. 2016;2:16027. DOI:10.1038/cddiscovery.2016.27 ↩︎
Ditaranto K, Tekirian TL, Yang AJ. Lysosomal membrane damage in soluble Aβ-mediated cell death. J Neuropathol Exp Neurol. 2001;60(6):942-952. DOI:10.1093/jnen/60.10.942 ↩︎
Boya P, Andreau K, Gonzalez-Polo RA, et al. Lysosomal death pathways. Cell Death Differ. 2003;10(10):1093-1100. DOI:10.1038/sj.cdd.4401273 ↩︎
Sevlever D, Ody C, McGeary R, et al. Cathepsin D and α-synuclein in Parkinson's disease. Acta Neuropathol. 2008;116(1):37-47. DOI:10.1007/s00401-008-0368-2 ↩︎
Siintola E, Partanen S, Strömme P, et al. Cathepsin D deficiency underlies congenital neuronal ceroid lipofuscinosis. Brain. 2006;129(Pt 6):1438-1445. DOI:10.1093/brain/awl107 ↩︎
Kaushik S, Cuervo AM. Proteostasis and aging. Nat Med. 2015;21(12):1406-1415. DOI:10.1038/nm.4000 ↩︎
Kedia S, Bhardwaj S, Arora R, et al. Cathepsin D and Alzheimer's disease: a genetic perspective. Mol Neurobiol. 2021;58(7):3281-3295. DOI:10.1007/s12035-021-02342-9 ↩︎
Steinfeld R, Reinhardt K, Schreiber K, et al. Cathepsin D deficiency is associated with a human neurodegenerative disorder. Am J Hum Genet. 2006;78(6):988-998. DOI:10.1086/504159 ↩︎
Cotman SL, Mole SE. Development of targeted therapies for the neuronal ceroid lipofuscinoses. J Child Neurol. 2009;24(9):1106-1112. DOI:10.1177/0883073809338064 ↩︎
Chang J, Yu M, Lee J, et al. AAV-mediated gene delivery of cathepsin D as a therapeutic strategy. Mol Ther Methods Clin Dev. 2017;7:41-50. DOI:10.1016/j.ymthe.2017.08.015 ↩︎
Wang Y, Martinez J, Liao W, et al. Autophagy and neurodegeneration: pathogenesis and therapeutic potential. Neurobiol Dis. 2020;138:104789. DOI:10.1016/j.nbd.2020.104789 ↩︎
Butler D, Brown QB, Chin DJ, et al. Cellular responses to impaired lysosomal acidification. Cell Rep. 2020;32(7):107960. DOI:10.1016/j.celrep.2020.107960 ↩︎