Tripeptidyl peptidase I
Tripeptidyl-peptidase 1, also known as Lysosomal pepstatin-insensitive protease, is an enzyme that in humans is encoded by the TPP1 gene.[5][6] TPP1 should not be confused with the TPP1 shelterin protein which protects telomeres and is encoded by the ACD gene.[7] Mutations in the TPP1 gene leads to late infantile neuronal ceroid lipofuscinosis.[8]
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| Aliases | TPP1, CLN2, LPIC, SCAR7, TPP-1, GIG1, Tripeptidyl peptidase I, tripeptidyl peptidase 1 | ||||||||||||||||||||||||||||||||||||||||||||||||||
| External IDs | OMIM: 607998 MGI: 1336194 HomoloGene: 335 GeneCards: TPP1 | ||||||||||||||||||||||||||||||||||||||||||||||||||
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Structure
Gene
The human gene TPP1 encodes a member of the sedolisin family of serine proteases. The human gene has 13 exons and locates at the chromosome band 11p15.[6]
Protein
The human TPP1 is 61kDa in size and composed of 563 amino acids. An isoform of 34.5kDa and 320 amino acids is generated by alternative splicing and a peptide fragment of 1-243 amino acid is missing.[9] TPP1 contains a globular structure with a subtilisin-like fold, a Ser475-Glu272-Asp360 catalytic triad. It also contains an octahedrally coordinated Ca2+-binding site that are characteristic features of the S53 sedolisin family of peptidases. Unlike other S53 peptidases, it has steric constraints on the P4 substrate pocket, which might contribute to its preferential cleavage of tripeptides from the unsubstituted N-terminus of proteins. Two alternative conformations of the catalytic Asp276 are associated with the activation status of TPP1.[10]
Function
High expression of TPP1 is found in bone marrow, placenta, lung, pineal and lymphocytes. The protease functions in the lysosome to cleave N-terminal tripeptides from substrates and has weaker endopeptidase activity. It is synthesized as a catalytically inactive enzyme which is activated and autoproteolyzed upon acidification.
Clinical significance
The neuronal ceroid lipofuscinoses (NCLs) are a group of inherited neurodegenerative disorders with pathological phenotypes that auto fluorescent lipopigments present in neurons and other cell types. Over the past two decades, accumulating evidences indicates that NCLs are caused by mutations in eight different genes, including genes encoding several soluble proteins (cathepsin D, PPT1, and TPP1).[11] Mutations of gene TPP1 result in late-infantile neuronal ceroid lipofuscinosis which is associated with the failure to degrade specific neuropeptides and a subunit of ATP synthase in the lysosome.[12] Mutations in the TPP1 gene lead to late infantile neuronal ceroid lipofuscinosis, a fatal neurodegenerative disease of childhood.[10] It has been demonstrated that a single injection of intravitreal implantation of autologous bone marrow derived stem cells transduced with a TPP1 expression construct at an early stage in the disease progression could substantially inhibit the development of disease-related retinal function deficits and structural changes. This result implies that ex vivo gene therapy using autologous stem cells may be an effective means of achieving sustained delivery of therapeutic compounds to tissues such as the retina for which systemic administration would be ineffective.[13]
References
- GRCh38: Ensembl release 89: ENSG00000166340 - Ensembl, May 2017
- GRCm38: Ensembl release 89: ENSMUSG00000030894 - Ensembl, May 2017
- "Human PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
- "Mouse PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
- Liu CG, Sleat DE, Donnelly RJ, Lobel P (June 1998). "Structural organization and sequence of CLN2, the defective gene in classical late infantile neuronal ceroid lipofuscinosis". Genomics. 50 (2): 206–12. doi:10.1006/geno.1998.5328. PMID 9653647.
- "Entrez Gene: TPP1 tripeptidyl peptidase I".
- "ACD ACD, shelterin complex subunit and telomerase recruitment factor [Homo sapiens (human)] - Gene - NCBI". www.ncbi.nlm.nih.gov. Retrieved 2017-02-03.
- Bukina AM, Tsvetkova IV, Semiachkina AN, Il'ina ES (Nov 2002). "[Tripeptidyl peptidase 1 deficiency in neuronal ceroid lipofuscinosis. A novel mutation]". Voprosy Medit︠s︡inskoĭ Khimii. 48 (6): 594–8. PMID 12698559.
- "Uniprot: O14773 - TPP1_HUMAN".
- Pal A, Kraetzner R, Gruene T, Grapp M, Schreiber K, Grønborg M, Urlaub H, Becker S, Asif AR, Gärtner J, Sheldrick GM, Steinfeld R (February 2009). "Structure of tripeptidyl-peptidase I provides insight into the molecular basis of late infantile neuronal ceroid lipofuscinosis". The Journal of Biological Chemistry. 284 (6): 3976–84. doi:10.1074/jbc.M806947200. PMID 19038966.
- Getty AL, Pearce DA (February 2011). "Interactions of the proteins of neuronal ceroid lipofuscinosis: clues to function". Cellular and Molecular Life Sciences. 68 (3): 453–74. doi:10.1007/s00018-010-0468-6. PMC 4120758. PMID 20680390.
- Gardiner RM (2000). "The molecular genetic basis of the neuronal ceroid lipofuscinoses". Neurological Sciences. 21 (3 Suppl): S15–9. doi:10.1007/s100720070035. PMID 11073223. S2CID 9550598.
- Tracy CJ, Whiting RE, Pearce JW, Williamson BG, Vansteenkiste DP, Gillespie LE, Castaner LJ, Bryan JN, Coates JR, Jensen CA, Katz ML (September 2016). "Intravitreal implantation of TPP1-transduced stem cells delays retinal degeneration in canine CLN2 neuronal ceroid lipofuscinosis". Experimental Eye Research. 152: 77–87. doi:10.1016/j.exer.2016.09.003. PMID 27637672.
Further reading
- Mole SE, Mitchison HM, Munroe PB (1999). "Molecular basis of the neuronal ceroid lipofuscinoses: mutations in CLN1, CLN2, CLN3, and CLN5". Human Mutation. 14 (3): 199–215. doi:10.1002/(SICI)1098-1004(1999)14:3<199::AID-HUMU3>3.0.CO;2-A. PMID 10477428.
- Dawson G, Cho S (April 2000). "Batten's disease: clues to neuronal protein catabolism in lysosomes". Journal of Neuroscience Research. 60 (2): 133–40. doi:10.1002/(SICI)1097-4547(20000415)60:2<133::AID-JNR1>3.0.CO;2-3. PMID 10740217. S2CID 28786470.
- Hofmann SL, Atashband A, Cho SK, Das AK, Gupta P, Lu JY (August 2002). "Neuronal ceroid lipofuscinoses caused by defects in soluble lysosomal enzymes (CLN1 and CLN2)". Current Molecular Medicine. 2 (5): 423–37. doi:10.2174/1566524023362294. PMID 12125808.
- Maruyama K, Sugano S (January 1994). "Oligo-capping: a simple method to replace the cap structure of eukaryotic mRNAs with oligoribonucleotides". Gene. 138 (1–2): 171–4. doi:10.1016/0378-1119(94)90802-8. PMID 8125298.
- Page AE, Fuller K, Chambers TJ, Warburton MJ (November 1993). "Purification and characterization of a tripeptidyl peptidase I from human osteoclastomas: evidence for its role in bone resorption". Archives of Biochemistry and Biophysics. 306 (2): 354–9. doi:10.1006/abbi.1993.1523. PMID 8215436.
- Sleat DE, Donnelly RJ, Lackland H, Liu CG, Sohar I, Pullarkat RK, Lobel P (September 1997). "Association of mutations in a lysosomal protein with classical late-infantile neuronal ceroid lipofuscinosis". Science. 277 (5333): 1802–5. doi:10.1126/science.277.5333.1802. PMID 9295267.
- Suzuki Y, Yoshitomo-Nakagawa K, Maruyama K, Suyama A, Sugano S (October 1997). "Construction and characterization of a full length-enriched and a 5'-end-enriched cDNA library". Gene. 200 (1–2): 149–56. doi:10.1016/S0378-1119(97)00411-3. PMID 9373149.
- Rawlings ND, Barrett AJ (January 1999). "Tripeptidyl-peptidase I is apparently the CLN2 protein absent in classical late-infantile neuronal ceroid lipofuscinosis". Biochimica et Biophysica Acta (BBA) - Protein Structure and Molecular Enzymology. 1429 (2): 496–500. doi:10.1016/S0167-4838(98)00238-6. PMID 9989235.
- Vines DJ, Warburton MJ (January 1999). "Classical late infantile neuronal ceroid lipofuscinosis fibroblasts are deficient in lysosomal tripeptidyl peptidase I". FEBS Letters. 443 (2): 131–5. doi:10.1016/S0014-5793(98)01683-4. PMID 9989590. S2CID 41696666.
- Sleat DE, Gin RM, Sohar I, Wisniewski K, Sklower-Brooks S, Pullarkat RK, Palmer DN, Lerner TJ, Boustany RM, Uldall P, Siakotos AN, Donnelly RJ, Lobel P (June 1999). "Mutational analysis of the defective protease in classic late-infantile neuronal ceroid lipofuscinosis, a neurodegenerative lysosomal storage disorder". American Journal of Human Genetics. 64 (6): 1511–23. doi:10.1086/302427. PMC 1377895. PMID 10330339.
- Junaid MA, Wu G, Pullarkat RK (January 2000). "Purification and characterization of bovine brain lysosomal pepstatin-insensitive proteinase, the gene product deficient in the human late-infantile neuronal ceroid lipofuscinosis". Journal of Neurochemistry. 74 (1): 287–94. doi:10.1046/j.1471-4159.2000.0740287.x. PMID 10617131. S2CID 25342240.
- Ezaki J, Takeda-Ezaki M, Oda K, Kominami E (February 2000). "Characterization of endopeptidase activity of tripeptidyl peptidase-I/CLN2 protein which is deficient in classical late infantile neuronal ceroid lipofuscinosis". Biochemical and Biophysical Research Communications. 268 (3): 904–8. doi:10.1006/bbrc.2000.2207. PMID 10679303.
- Haines JL, Boustany RM, Alroy J, Auger KJ, Shook KS, Terwedow H, Lerner TJ (March 1998). "Chromosomal localization of two genes underlying late-infantile neuronal ceroid lipofuscinosis". Neurogenetics. 1 (3): 217–22. doi:10.1007/s100480050032. PMID 10737126. S2CID 23303630.
- Ezaki J, Takeda-Ezaki M, Kominami E (September 2000). "Tripeptidyl peptidase I, the late infantile neuronal ceroid lipofuscinosis gene product, initiates the lysosomal degradation of subunit c of ATP synthase". Journal of Biochemistry. 128 (3): 509–16. doi:10.1093/oxfordjournals.jbchem.a022781. PMID 10965052.
- Lin L, Sohar I, Lackland H, Lobel P (January 2001). "The human CLN2 protein/tripeptidyl-peptidase I is a serine protease that autoactivates at acidic pH". The Journal of Biological Chemistry. 276 (3): 2249–55. doi:10.1074/jbc.M008562200. PMID 11054422.
- Lam CW, Poon PM, Tong SF, Ko CH (March 2001). "Two novel CLN2 gene mutations in a Chinese patient with classical late-infantile neuronal ceroid lipofuscinosis". American Journal of Medical Genetics. 99 (2): 161–3. doi:10.1002/1096-8628(2001)9999:9999<::AID-AJMG1145>3.0.CO;2-Z. PMID 11241479.
- Zhong N, Moroziewicz DN, Ju W, Jurkiewicz A, Johnston L, Wisniewski KE, Brown WT (2001). "Heterogeneity of late-infantile neuronal ceroid lipofuscinosis". Genetics in Medicine. 2 (6): 312–8. doi:10.1097/00125817-200011000-00002. PMID 11339651.