| Structural highlights
Disease
[PSB8_HUMAN] CANDLE syndrome;Nakajo-Nishimura syndrome;JMP syndrome. The disease is caused by mutations affecting the gene represented in this entry.
Function
[PSA7_HUMAN] The proteasome is a multicatalytic proteinase complex which is characterized by its ability to cleave peptides with Arg, Phe, Tyr, Leu, and Glu adjacent to the leaving group at neutral or slightly basic pH. The proteasome has an ATP-dependent proteolytic activity. Plays an important role in the regulation of cell proliferation or cell cycle control, transcriptional regulation, immune and stress response, cell differentiation, and apoptosis. Interacts with some important proteins involved in transcription factor regulation, cell cycle transition, viral replication and even tumor initiation and progression. Inhibits the transactivation function of HIF-1A under both normoxic and hypoxia-mimicking conditions. The interaction with EMAP2 increases the proteasome-mediated HIF-1A degradation under the hypoxic conditions. Plays a role in hepatitis C virus internal ribosome entry site-mediated translation. Mediates nuclear translocation of the androgen receptor (AR) and thereby enhances androgen-mediated transactivation. Promotes MAVS degradation and thereby negatively regulates MAVS-mediated innate immune response.[1] [2] [3] [4] [5] [PSB1_HUMAN] The proteasome is a multicatalytic proteinase complex which is characterized by its ability to cleave peptides with Arg, Phe, Tyr, Leu, and Glu adjacent to the leaving group at neutral or slightly basic pH. The proteasome has an ATP-dependent proteolytic activity. [PSB8_HUMAN] The proteasome is a multicatalytic proteinase complex which is characterized by its ability to cleave peptides with Arg, Phe, Tyr, Leu, and Glu adjacent to the leaving group at neutral or slightly basic pH. The proteasome has an ATP-dependent proteolytic activity. This subunit is involved in antigen processing to generate class I binding peptides. Replacement of PSMB5 by PSMB8 increases the capacity of the immunoproteasome to cleave model peptides after hydrophobic and basic residues. Acts as a major component of interferon gamma-induced sensitivity. Plays a key role in apoptosis via the degradation of the apoptotic inhibitor MCL1. May be involved in the inflammatory response pathway. In cancer cells, substitution of isoform 1 (E2) by isoform 2 (E1) results in immunoproteasome deficiency. Required for the differentiation of preadipocytes into adipocytes.[6] [7] [8] [9] [PSA3_HUMAN] The proteasome is a multicatalytic proteinase complex which is characterized by its ability to cleave peptides with Arg, Phe, Tyr, Leu, and Glu adjacent to the leaving group at neutral or slightly basic pH. The proteasome has an ATP-dependent proteolytic activity. Binds to the C-terminus of CDKN1A and thereby mediates its degradation. Negatively regulates the membrane trafficking of the cell-surface thromboxane A2 receptor (TBXA2R) isoform 2.[10] [11] [PSA4_HUMAN] The proteasome is a multicatalytic proteinase complex which is characterized by its ability to cleave peptides with Arg, Phe, Tyr, Leu, and Glu adjacent to the leaving group at neutral or slightly basic pH. The proteasome has an ATP-dependent proteolytic activity. [PSB2_HUMAN] The proteasome is a multicatalytic proteinase complex which is characterized by its ability to cleave peptides with Arg, Phe, Tyr, Leu, and Glu adjacent to the leaving group at neutral or slightly basic pH. The proteasome has an ATP-dependent proteolytic activity. This subunit has a trypsin-like activity. [PSB10_HUMAN] The proteasome is a multicatalytic proteinase complex which is characterized by its ability to cleave peptides with Arg, Phe, Tyr, Leu, and Glu adjacent to the leaving group at neutral or slightly basic pH. The proteasome has an ATP-dependent proteolytic activity. This subunit is involved in antigen processing to generate class I binding peptides. [PSB4_HUMAN] The proteasome is a multicatalytic proteinase complex which is characterized by its ability to cleave peptides with Arg, Phe, Tyr, Leu, and Glu adjacent to the leaving group at neutral or slightly basic pH. The proteasome has an ATP-dependent proteolytic activity. Mediates the lipopolysaccharide-induced signal macrophage proteasome (By similarity). SMAD1/OAZ1/PSMB4 complex mediates the degradation of the CREBBP/EP300 repressor SNIP1.[12] [PSA6_HUMAN] The proteasome is a multicatalytic proteinase complex which is characterized by its ability to cleave peptides with Arg, Phe, Tyr, Leu, and Glu adjacent to the leaving group at neutral or slightly basic pH. The proteasome has an ATP-dependent proteolytic activity. [PSB9_HUMAN] The proteasome is a multicatalytic proteinase complex which is characterized by its ability to cleave peptides with Arg, Phe, Tyr, Leu, and Glu adjacent to the leaving group at neutral or slightly basic pH. The proteasome has an ATP-dependent proteolytic activity. This subunit is involved in antigen processing to generate class I binding peptides. Replacement of PSMB6 by PSMB9 increases the capacity of the immunoproteasome to cleave model peptides after hydrophobic and basic residues.[13] [PSA1_HUMAN] The proteasome is a multicatalytic proteinase complex which is characterized by its ability to cleave peptides with Arg, Phe, Tyr, Leu, and Glu adjacent to the leaving group at neutral or slightly basic pH. The proteasome has an ATP-dependent proteolytic activity. Mediates the lipopolysaccharide-induced signal transduction in the macrophage proteasome (By similarity). Might be involved in the anti-inflammatory response of macrophages during the interaction with C.albicans heat-inactivated cells (By similarity). [PSB3_HUMAN] The proteasome is a multicatalytic proteinase complex which is characterized by its ability to cleave peptides with Arg, Phe, Tyr, Leu, and Glu adjacent to the leaving group at neutral or slightly basic pH. The proteasome has an ATP-dependent proteolytic activity. [PSA2_HUMAN] The proteasome is a multicatalytic proteinase complex which is characterized by its ability to cleave peptides with Arg, Phe, Tyr, Leu, and Glu adjacent to the leaving group at neutral or slightly basic pH. The proteasome has an ATP-dependent proteolytic activity. PSMA2 may have a potential regulatory effect on another component(s) of the proteasome complex through tyrosine phosphorylation. [PSA5_HUMAN] The proteasome is a multicatalytic proteinase complex which is characterized by its ability to cleave peptides with Arg, Phe, Tyr, Leu, and Glu adjacent to the leaving group at neutral or slightly basic pH. The proteasome has an ATP-dependent proteolytic activity.
Publication Abstract from PubMed
Proteasome inhibitors benefit patients with multiple myeloma and B cell-dependent autoimmune disorders but exert toxicity from inhibition of proteasomes in other cells. Toxicity should be minimized by reversible inhibition of the immunoproteasome beta5i subunit while sparing the constitutive beta5c subunit. Here we report beta5i-selective inhibition by asparagine-ethylenediamine (AsnEDA)-based compounds and present the high-resolution cryo-EM structural analysis of the human immunoproteasome. Despite inhibiting noncompetitively, an AsnEDA inhibitor binds the active site. Hydrophobic interactions are accompanied by hydrogen bonding with beta5i and beta6 subunits. The inhibitors are far more cytotoxic for myeloma and lymphoma cell lines than for hepatocarcinoma or non-activated lymphocytes. They block human B-cell proliferation and promote apoptotic cell death selectively in antibody-secreting B cells, and to a lesser extent in activated human T cells. Reversible, beta5i-selective inhibitors may be useful for treatment of diseases involving activated or neoplastic B cells or activated T cells.
Structure of human immunoproteasome with a reversible and noncompetitive inhibitor that selectively inhibits activated lymphocytes.,Santos RLA, Bai L, Singh PK, Murakami N, Fan H, Zhan W, Zhu Y, Jiang X, Zhang K, Assker JP, Nathan CF, Li H, Azzi J, Lin G Nat Commun. 2017 Nov 22;8(1):1692. doi: 10.1038/s41467-017-01760-5. PMID:29167449[14]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Cho S, Choi YJ, Kim JM, Jeong ST, Kim JH, Kim SH, Ryu SE. Binding and regulation of HIF-1alpha by a subunit of the proteasome complex, PSMA7. FEBS Lett. 2001 Jun 1;498(1):62-6. PMID:11389899
- ↑ Kruger M, Beger C, Welch PJ, Barber JR, Manns MP, Wong-Staal F. Involvement of proteasome alpha-subunit PSMA7 in hepatitis C virus internal ribosome entry site-mediated translation. Mol Cell Biol. 2001 Dec;21(24):8357-64. PMID:11713272 doi:http://dx.doi.org/10.1128/MCB.21.24.8357-8364.2001
- ↑ Lin HK, Altuwaijri S, Lin WJ, Kan PY, Collins LL, Chang C. Proteasome activity is required for androgen receptor transcriptional activity via regulation of androgen receptor nuclear translocation and interaction with coregulators in prostate cancer cells. J Biol Chem. 2002 Sep 27;277(39):36570-6. Epub 2002 Jul 15. PMID:12119296 doi:http://dx.doi.org/10.1074/jbc.M204751200
- ↑ Du H, Huang X, Wang S, Wu Y, Xu W, Li M. PSMA7, a potential biomarker of diseases. Protein Pept Lett. 2009;16(5):486-9. PMID:19442227
- ↑ Jia Y, Song T, Wei C, Ni C, Zheng Z, Xu Q, Ma H, Li L, Zhang Y, He X, Xu Y, Shi W, Zhong H. Negative regulation of MAVS-mediated innate immune response by PSMA7. J Immunol. 2009 Oct 1;183(7):4241-8. doi: 10.4049/jimmunol.0901646. Epub 2009 Sep, 4. PMID:19734229 doi:http://dx.doi.org/10.4049/jimmunol.0901646
- ↑ Heink S, Fricke B, Ludwig D, Kloetzel PM, Kruger E. Tumor cell lines expressing the proteasome subunit isoform LMP7E1 exhibit immunoproteasome deficiency. Cancer Res. 2006 Jan 15;66(2):649-52. PMID:16423992 doi:http://dx.doi.org/10.1158/0008-5472.CAN-05-2872
- ↑ Yang Z, Gagarin D, St Laurent G 3rd, Hammell N, Toma I, Hu CA, Iwasa A, McCaffrey TA. Cardiovascular inflammation and lesion cell apoptosis: a novel connection via the interferon-inducible immunoproteasome. Arterioscler Thromb Vasc Biol. 2009 Aug;29(8):1213-9. doi:, 10.1161/ATVBAHA.109.189407. Epub 2009 May 14. PMID:19443843 doi:http://dx.doi.org/10.1161/ATVBAHA.109.189407
- ↑ Kitamura A, Maekawa Y, Uehara H, Izumi K, Kawachi I, Nishizawa M, Toyoshima Y, Takahashi H, Standley DM, Tanaka K, Hamazaki J, Murata S, Obara K, Toyoshima I, Yasutomo K. A mutation in the immunoproteasome subunit PSMB8 causes autoinflammation and lipodystrophy in humans. J Clin Invest. 2011 Oct;121(10):4150-60. doi: 10.1172/JCI58414. Epub 2011 Sep 1. PMID:21881205 doi:http://dx.doi.org/10.1172/JCI58414
- ↑ Akiyama K, Kagawa S, Tamura T, Shimbara N, Takashina M, Kristensen P, Hendil KB, Tanaka K, Ichihara A. Replacement of proteasome subunits X and Y by LMP7 and LMP2 induced by interferon-gamma for acquirement of the functional diversity responsible for antigen processing. FEBS Lett. 1994 Apr 18;343(1):85-8. PMID:8163024
- ↑ Touitou R, Richardson J, Bose S, Nakanishi M, Rivett J, Allday MJ. A degradation signal located in the C-terminus of p21WAF1/CIP1 is a binding site for the C8 alpha-subunit of the 20S proteasome. EMBO J. 2001 May 15;20(10):2367-75. PMID:11350925 doi:http://dx.doi.org/10.1093/emboj/20.10.2367
- ↑ Sasaki M, Sukegawa J, Miyosawa K, Yanagisawa T, Ohkubo S, Nakahata N. Low expression of cell-surface thromboxane A2 receptor beta-isoform through the negative regulation of its membrane traffic by proteasomes. Prostaglandins Other Lipid Mediat. 2007 Jun;83(4):237-49. Epub 2006 Dec 27. PMID:17499743 doi:http://dx.doi.org/10.1016/j.prostaglandins.2006.12.001
- ↑ Lin Y, Martin J, Gruendler C, Farley J, Meng X, Li BY, Lechleider R, Huff C, Kim RH, Grasser WA, Paralkar V, Wang T. A novel link between the proteasome pathway and the signal transduction pathway of the bone morphogenetic proteins (BMPs). BMC Cell Biol. 2002 Jun 21;3:15. PMID:12097147
- ↑ Akiyama K, Kagawa S, Tamura T, Shimbara N, Takashina M, Kristensen P, Hendil KB, Tanaka K, Ichihara A. Replacement of proteasome subunits X and Y by LMP7 and LMP2 induced by interferon-gamma for acquirement of the functional diversity responsible for antigen processing. FEBS Lett. 1994 Apr 18;343(1):85-8. PMID:8163024
- ↑ Santos RLA, Bai L, Singh PK, Murakami N, Fan H, Zhan W, Zhu Y, Jiang X, Zhang K, Assker JP, Nathan CF, Li H, Azzi J, Lin G. Structure of human immunoproteasome with a reversible and noncompetitive inhibitor that selectively inhibits activated lymphocytes. Nat Commun. 2017 Nov 22;8(1):1692. doi: 10.1038/s41467-017-01760-5. PMID:29167449 doi:http://dx.doi.org/10.1038/s41467-017-01760-5
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