Cystatin B

CSTB redirects here. It can also refer to the Trade Union Confederation of Bolivian Workers.

Cystatin B (stefin B)
PDB rendering based on 1stf.
Available structures PDB 1STF, 2OCT
Identifiers
Symbols	CSTB; CST6; EPM1; PME; STFB
External IDs	OMIM: 601145 MGI: 109514 HomoloGene: 79 GeneCards: CSTB Gene
Gene Ontology Molecular function • protease binding • endopeptidase inhibitor activity • cysteine-type endopeptidase inhibitor activity • protein binding Cellular component • intracellular • nucleus • nucleolus • cytoplasm Biological process • adult locomotory behavior • negative regulation of peptidase activity • negative regulation of endopeptidase activity • regulation of apoptosis Sources: Amigo / QuickGO
RNA expression pattern
More reference expression data
Orthologs
Species	Human	Mouse
Entrez	1476	13014
Ensembl	ENSG00000160213	ENSMUSG00000005054
UniProt	P04080	Q62426
RefSeq (mRNA)	NM_000100	NM_007793.3
RefSeq (protein)	NP_000091	NP_031819.1
Location (UCSC)	Chr 21: 45.19 – 45.2 Mb	Chr 10: 77.89 – 77.89 Mb
PubMed search	[1]	[2]

Cystatin-B is a protein that in humans is encoded by the CSTB gene.^[1][2]

The cystatin superfamily encompasses proteins that contain multiple cystatin-like sequences. Some of the members are active cysteine protease inhibitors, while others have lost or perhaps never acquired this inhibitory activity. There are three inhibitory families in the superfamily, including the type 1 cystatins (stefins), type 2 cystatins and kininogens. This gene encodes a stefin that functions as an intracellular thiol protease inhibitor. The protein is able to form a dimer stabilized by noncovalent forces, inhibiting papain and cathepsins l, h and b. The protein is thought to play a role in protecting against the proteases leaking from lysosomes. Evidence indicates that mutations in this gene are responsible for the primary defects in patients with progressive myoclonic epilepsy (EPM1).^[2]

Interactions

Cystatin B has been shown to interact with Cathepsin B.^[3][4]

References

1. ^ Pennacchio LA, Lehesjoki AE, Stone NE, Willour VL, Virtaneva K, Miao J, D'Amato E, Ramirez L, Faham M, Koskiniemi M, Warrington JA, Norio R, de la Chapelle A, Cox DR, Myers RM (Apr 1996). "Mutations in the gene encoding cystatin B in progressive myoclonus epilepsy (EPM1)". Science 271 (5256): 1731–4. doi:10.1126/science.271.5256.1731. PMID 8596935. 
2. ^ ^{a b} "Entrez Gene: CSTB cystatin B (stefin B)". http://www.ncbi.nlm.nih.gov/sites/entrez?Db=gene&Cmd=ShowDetailView&TermToSearch=1476. 
3. ^ Pavlova, Alona; Björk Ingemar (Sep. 2003). "Grafting of features of cystatins C or B into the N-terminal region or second binding loop of cystatin A (stefin A) substantially enhances inhibition of cysteine proteinases". Biochemistry (United States) 42 (38): 11326–33. doi:10.1021/bi030119v. ISSN 0006-2960. PMID 14503883. 
4. ^ Pol, E; Björk I (Sep. 2001). "Role of the single cysteine residue, Cys 3, of human and bovine cystatin B (stefin B) in the inhibition of cysteine proteinases". Protein Sci. (United States) 10 (9): 1729–38. doi:10.1110/ps.11901. ISSN 0961-8368. PMC 2253190. PMID 11514663. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2253190. 

Further reading

• Turk V, Bode W (1991). "The cystatins: protein inhibitors of cysteine proteinases.". FEBS Lett. 285 (2): 213–9. doi:10.1016/0014-5793(91)80804-C. PMID 1855589. 
• Järvinen M, Rinne A, Hopsu-Havu VK (1988). "Human cystatins in normal and diseased tissues--a review.". Acta Histochem. 82 (1): 5–18. PMID 3122506. 
• Brown WM, Dziegielewska KM (1997). "Friends and relations of the cystatin superfamily--new members and their evolution.". Protein Sci. 6 (1): 5–12. doi:10.1002/pro.5560060102. PMC 2143511. PMID 9007972. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2143511. 
• Kos J, Lah TT (1998). "Cysteine proteinases and their endogenous inhibitors: target proteins for prognosis, diagnosis and therapy in cancer (review).". Oncol. Rep. 5 (6): 1349–61. PMID 9769367. 
• Stubbs MT, Laber B, Bode W, et al. (1990). "The refined 2.4 A X-ray crystal structure of recombinant human stefin B in complex with the cysteine proteinase papain: a novel type of proteinase inhibitor interaction.". EMBO J. 9 (6): 1939–47. PMC 551902. PMID 2347312. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=551902. 
• Jerala R, Trstenjak M, Lenarcic B, Turk V (1988). "Cloning a synthetic gene for human stefin B and its expression in E. coli.". FEBS Lett. 239 (1): 41–4. doi:10.1016/0014-5793(88)80541-6. PMID 3053245. 
• Lenarcic B, Kos J, Dolenc I, et al. (1988). "Cathepsin D inactivates cysteine proteinase inhibitors, cystatins.". Biochem. Biophys. Res. Commun. 154 (2): 765–72. doi:10.1016/0006-291X(88)90206-9. PMID 3261170. 
• Ritonja A, Machleidt W, Barrett AJ (1985). "Amino acid sequence of the intracellular cysteine proteinase inhibitor cystatin B from human liver.". Biochem. Biophys. Res. Commun. 131 (3): 1187–92. doi:10.1016/0006-291X(85)90216-5. PMID 3902020. 
• Spiess E, Brüning A, Gack S, et al. (1994). "Cathepsin B activity in human lung tumor cell lines: ultrastructural localization, pH sensitivity, and inhibitor status at the cellular level.". J. Histochem. Cytochem. 42 (7): 917–29. PMID 8014475. 
• Lehesjoki AE, Koskiniemi M, Norio R, et al. (1993). "Localization of the EPM1 gene for progressive myoclonus epilepsy on chromosome 21: linkage disequilibrium allows high resolution mapping.". Hum. Mol. Genet. 2 (8): 1229–34. doi:10.1093/hmg/2.8.1229. PMID 8104628. 
• Pennacchio LA, Myers RM (1997). "Isolation and characterization of the mouse cystatin B gene.". Genome Res. 6 (11): 1103–9. doi:10.1101/gr.6.11.1103. PMID 8938434. 
• Lalioti MD, Mirotsou M, Buresi C, et al. (1997). "Identification of mutations in cystatin B, the gene responsible for the Unverricht-Lundborg type of progressive myoclonus epilepsy (EPM1).". Am. J. Hum. Genet. 60 (2): 342–51. PMC 1712389. PMID 9012407. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1712389. 
• Lafrenière RG, Rochefort DL, Chrétien N, et al. (1997). "Unstable insertion in the 5' flanking region of the cystatin B gene is the most common mutation in progressive myoclonus epilepsy type 1, EPM1.". Nat. Genet. 15 (3): 298–302. doi:10.1038/ng0397-298. PMID 9054946. 
• Virtaneva K, D'Amato E, Miao J, et al. (1997). "Unstable minisatellite expansion causing recessively inherited myoclonus epilepsy, EPM1.". Nat. Genet. 15 (4): 393–6. doi:10.1038/ng0497-393. PMID 9090386. 
• Bespalova IN, Adkins S, Pranzatelli M, Burmeister M (1997). "Novel cystatin B mutation and diagnostic PCR assay in an Unverricht-Lundborg progressive myoclonus epilepsy patient.". Am. J. Med. Genet. 74 (5): 467–71. doi:10.1002/(SICI)1096-8628(19970919)74:5<467::AID-AJMG1>3.0.CO;2-L. PMID 9342192. 

External Links

• GeneReviews/NCBI/NIH/UW entry on Unverricht-Lundborg Disease or EPM1
• The MEROPS online database for peptidases and their inhibitors: I25.003