PSMB1

PSMB1
Available structures PDB Ortholog search: PDBe RCSB List of PDB id codes 4R3O, 4R67, 5A0Q
Identifiers
Aliases	PSMB1 , HC5, PMSB1, PSC5, proteasome subunit beta 1, proteasome 20S subunit beta 1
External IDs	OMIM: 602017 MGI: 104884 HomoloGene: 2087 GeneCards: PSMB1
Gene location (Human) Chr. Chromosome 6 (human) [1] Band 6q27 Start 170,535,120 bp [1] End 170,553,307 bp [1]
RNA expression pattern More reference expression data
Gene ontology Molecular function • endopeptidase activity • peptidase activity • GO:0001948 protein binding • threonine-type endopeptidase activity • hydrolase activity Cellular component • cytoplasm • cytosol • nucleoplasm • proteasome complex • extracellular exosome • nucleus • proteasome core complex • extracellular region • secretory granule lumen • ficolin-1-rich granule lumen • proteasome core complex, beta-subunit complex Biological process • regulation of cellular amino acid metabolic process • antigen processing and presentation of exogenous peptide antigen via MHC class I, TAP-dependent • regulation of mRNA stability • positive regulation of canonical Wnt signaling pathway • protein polyubiquitination • stimulatory C-type lectin receptor signaling pathway • tumor necrosis factor-mediated signaling pathway • MAPK cascade • proteolysis • Fc-epsilon receptor signaling pathway • NIK/NF-kappaB signaling • anaphase-promoting complex-dependent catabolic process • proteolysis involved in cellular protein catabolic process • T cell receptor signaling pathway • negative regulation of canonical Wnt signaling pathway • proteasome-mediated ubiquitin-dependent protein catabolic process • GO:0022415 viral process • Wnt signaling pathway, planar cell polarity pathway • negative regulation of G2/M transition of mitotic cell cycle • protein deubiquitination • SCF-dependent proteasomal ubiquitin-dependent protein catabolic process • neutrophil degranulation • transmembrane transport • regulation of transcription from RNA polymerase II promoter in response to hypoxia • post-translational protein modification • regulation of hematopoietic stem cell differentiation • proteasomal protein catabolic process • proteasomal ubiquitin-independent protein catabolic process • interleukin-1-mediated signaling pathway • regulation of mitotic cell cycle phase transition Sources:Amigo / QuickGO
Orthologs
Species	Human	Mouse
Entrez	5689	19170
Ensembl	ENSG00000008018 ENSG00000281184	ENSMUSG00000014769
UniProt	P20618	O09061
RefSeq (mRNA)	NM_002793	NM_011185
RefSeq (protein)	NP_002784	NP_035315
Location (UCSC)	Chr 6: 170.54 – 170.55 Mb	n/a
PubMed search	[2]	[3]
Wikidata
View/Edit Human View/Edit Mouse

Proteasome subunit beta type-1 also known as 20S proteasome subunit beta-6 (based on systematic nomenclature) is a protein that in humans is encoded by the PSMB1 gene. ^[4] This protein is one of the 17 essential subunits (alpha subunits 1-7, constitutive beta subunits 1-7, and inducible subunits including beta1i, beta2i, beta5i) that contributes to the complete assembly of 20S proteasome complex. In particular, proteasome subunit beta type-1, along with other beta subunits, assemble into two heptameric rings and subsequently a proteolytic chamber for substrate degradation. The eukaryotic proteasome recognized degradable proteins, including damaged proteins for protein quality control purpose or key regulatory protein components for dynamic biological processes. An essential function of a modified proteasome, the immunoproteasome, is the processing of class I MHC peptides.

Structure

Gene

The gene PSMB1 encodes a member of the proteasome B-type family, also known as the T1B family, that is a 20S core beta subunit. This gene is tightly linked to the TBP (TATA-binding protein) gene in human and in mouse, and is transcribed in the opposite orientation in both species. ^[5] The gene has 6 exons and locates at chromosome band 6q27.

Protein

The human protein proteasome subunit beta type-1 is 26.5 kDa in size and composed of 241 amino acids. The calculated theoretical pI of this protein is 8.27.

Complex assembly

The proteasome is a multicatalytic proteinase complex with a highly ordered 20S core structure. This barrel-shaped core structure is composed of 4 axially stacked rings of 28 non-identical subunits: the two end rings are each formed by 7 alpha subunits, and the two central rings are each formed by 7 beta subunits. Three beta subunits (beta1, beta2, and beta5) each contains a proteolytic active site and has distinct substrate preferences. Proteasomes are distributed throughout eukaryotic cells at a high concentration and cleave peptides in an ATP/ubiquitin-dependent process in a non-lysosomal pathway. ^{[6] [7]}

Function

Protein functions are supported by its tertiary structure and its interaction with associating partners. As one of 28 subunits of 20S proteasome, protein proteasome subunit beta type-1 contributes to form a proteolytic environment for substrate degradation. Evidences of the crystal structures of isolated 20S proteasome complex demonstrate that the two rings of beta subunits form a proteolytic chamber and maintain all their active sites of proteolysis within the chamber. ^[7] Concomitantly, the rings of alpha subunits form the entrance for substrates entering the proteolytic chamber. In an inactivated 20S proteasome complex, the gate into the internal proteolytic chamber are guarded by the N-terminal tails of specific alpha-subunit. This unique structure design prevents random encounter between proteolytic active sites and protein substrate, which makes protein degradation a well-regulated process. ^{[8] [9]} 20S proteasome complex, by itself, is usually functionally inactive. The proteolytic capacity of 20S core particle (CP) can be activated when CP associates with one or two regulatory particles (RP) on one or both side of alpha rings. These regulatory particles include 19S proteasome complexes, 11S proteasome complex, etc. Following the CP-RP association, the confirmation of certain alpha subunits will change and consequently cause the opening of substrate entrance gate. Besides RPs, the 20S proteasomes can also be effectively activated by other mild chemical treatments, such as exposure to low levels of sodium dodecylsulfate (SDS) or NP-14. ^{[9] [10]}

Clinical significance

The proteasome and its subunits are of clinical significance for at least two reasons: (1) a compromised complex assembly or a dysfunctional proteasome can be associated with the underlying pathophysiology of specific diseases, and (2) they can be exploited as drug targets for therapeutic interventions. More recently, more effort has been made to consider the proteasome for the development of novel diagnostic markers and strategies. An improved and comprehensive understanding of the pathophysiology of the proteasome should lead to clinical applications in the future.

The proteasomes form a pivotal component for the ubiquitin–proteasome system (UPS) ^[11] and corresponding cellular Protein Quality Control (PQC). Protein ubiquitination and subsequent proteolysis and degradation by the proteasome are important mechanisms in the regulation of the cell cycle, cell growth and differentiation, gene transcription, signal transduction and apoptosis. ^[12] Subsequently, a compromised proteasome complex assembly and function lead to reduced proteolytic activities and the accumulation of damaged or misfolded protein species. Such protein accumulation may contribute to the pathogenesis and phenotypic characteristics in neurodegenerative diseases, ^{[13] [14]} cardiovascular diseases, ^{[15] [16] [17]} inflammatory responses and autoimmune diseases, ^[18] and systemic DNA damage responses leading to malignancies. ^[19]

Several experimental and clinical studies have indicated that aberrations and deregulations of the UPS contribute to the pathogenesis of several neurodegenerative and myodegenerative disorders, including Alzheimer's disease, ^[20] Parkinson's disease ^[21] and Pick's disease, ^[22] Amyotrophic lateral sclerosis (ALS), ^[7] Huntington's disease, ^[21] Creutzfeldt–Jakob disease, ^[23] and motor neuron diseases, polyglutamine (PolyQ) diseases, Muscular dystrophies ^[24] and several rare forms of neurodegenerative diseases associated with dementia. ^[25] As part of the ubiquitin–proteasome system (UPS), the proteasome maintains cardiac protein homeostasis and thus plays a significant role in cardiac ischemic injury, ^[26] ventricular hypertrophy ^[27] and heart failure. ^[28] Additionally, evidence is accumulating that the UPS plays an essential role in malignant transformation. UPS proteolysis plays a major role in responses of cancer cells to stimulatory signals that are critical for the development of cancer. Accordingly, gene expression by degradation of transcription factors, such as p53, c-jun, c-Fos, NF-κB, c-Myc, HIF-1α, MATα2, STAT3, sterol-regulated element-binding proteins and androgen receptors are all controlled by the UPS and thus involved in the development of various malignancies. ^[29] Moreover, the UPS regulates the degradation of tumor suppressor gene products such as adenomatous polyposis coli (APC) in colorectal cancer, retinoblastoma (Rb). and von Hippel–Lindau tumor suppressor (VHL), as well as a number of proto-oncogenes (Raf, Myc, Myb, Rel, Src, Mos, ABL). The UPS is also involved in the regulation of inflammatory responses. This activity is usually attributed to the role of proteasomes in the activation of NF-κB which further regulates the expression of pro inflammatory cytokines such as TNF-α, IL-β, IL-8, adhesion molecules (ICAM-1, VCAM-1, P-selectin) and prostaglandins and nitric oxide (NO). ^[18] Additionally, the UPS also plays a role in inflammatory responses as regulators of leukocyte proliferation, mainly through proteolysis of cyclines and the degradation of CDK inhibitors. ^[30] Lastly, autoimmune disease patients with SLE, Sjögren syndrome and rheumatoid arthritis (RA) predominantly exhibit circulating proteasomes which can be applied as clinical biomarkers. ^[31]

The proteasome subunit beta type-1 (also known as 20S proteasome subunit beta-6) is a protein encoded by the PSMB1 gene in humans and has been a subject of investigations in several clinical conditions. For instance, a mutated form of PSMB1 displayed an increased nuclear translocation, which resulted in the activation of transcription in adipocytes relevant in diabetes mellitus. ^[32] Overall, the PSMB1 protein has been described in several forms of malignancies ^{[33] [34] [35]} such as follicular lymphoma ^[34] with an important mechanistic role in tumorigenesis. ^[36]

References

1. ENSG00000281184 GRCh38: Ensembl release 89: ENSG00000008018, ENSG00000281184 - Ensembl, May 2017
2. "Human PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
3. "Mouse PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
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5. "Entrez Gene: PSMB1 proteasome (prosome, macropain) subunit, beta type, 1".
6. Coux O, Tanaka K, Goldberg AL (1996). "Structure and functions of the 20S and 26S proteasomes". Annual Review of Biochemistry. 65: 801–47. doi:10.1146/annurev.bi.65.070196.004101. PMID   8811196.
7. Tomko RJ, Hochstrasser M (2013). "Molecular architecture and assembly of the eukaryotic proteasome". Annual Review of Biochemistry. 82: 415–45. doi:10.1146/annurev-biochem-060410-150257. PMC   3827779 . PMID   23495936.
8. Groll M, Ditzel L, Löwe J, Stock D, Bochtler M, Bartunik HD, Huber R (Apr 1997). "Structure of 20S proteasome from yeast at 2.4 A resolution". Nature. 386 (6624): 463–71. Bibcode:1997Natur.386..463G. doi:10.1038/386463a0. PMID   9087403. S2CID   4261663.
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10. Zong C, Gomes AV, Drews O, Li X, Young GW, Berhane B, Qiao X, French SW, Bardag-Gorce F, Ping P (Aug 2006). "Regulation of murine cardiac 20S proteasomes: role of associating partners". Circulation Research. 99 (4): 372–80. doi: 10.1161/01.RES.0000237389.40000.02 . PMID   16857963.
11. Kleiger G, Mayor T (Jun 2014). "Perilous journey: a tour of the ubiquitin-proteasome system". Trends in Cell Biology. 24 (6): 352–9. doi:10.1016/j.tcb.2013.12.003. PMC   4037451 . PMID   24457024.
12. Goldberg AL, Stein R, Adams J (Aug 1995). "New insights into proteasome function: from archaebacteria to drug development". Chemistry & Biology. 2 (8): 503–8. doi: 10.1016/1074-5521(95)90182-5 . PMID   9383453.
13. Sulistio YA, Heese K (Jan 2015). "The Ubiquitin–Proteasome System and Molecular Chaperone Deregulation in Alzheimer's Disease". Molecular Neurobiology. 53 (2): 905–31. doi:10.1007/s12035-014-9063-4. PMID   25561438. S2CID   14103185.
14. Ortega Z, Lucas JJ (2014). "Ubiquitin–proteasome system involvement in Huntington's disease". Frontiers in Molecular Neuroscience. 7: 77. doi: 10.3389/fnmol.2014.00077 . PMC   4179678 . PMID   25324717.
15. Sandri M, Robbins J (Jun 2014). "Proteotoxicity: an underappreciated pathology in cardiac disease". Journal of Molecular and Cellular Cardiology. 71: 3–10. doi:10.1016/j.yjmcc.2013.12.015. PMC   4011959 . PMID   24380730.
16. Drews O, Taegtmeyer H (Dec 2014). "Targeting the ubiquitin-proteasome system in heart disease: the basis for new therapeutic strategies". Antioxidants & Redox Signaling. 21 (17): 2322–43. doi:10.1089/ars.2013.5823. PMC   4241867 . PMID   25133688.
17. Wang ZV, Hill JA (Feb 2015). "Protein quality control and metabolism: bidirectional control in the heart". Cell Metabolism. 21 (2): 215–26. doi:10.1016/j.cmet.2015.01.016. PMC   4317573 . PMID   25651176.
18. Karin M, Delhase M (Feb 2000). "The I kappa B kinase (IKK) and NF-kappa B: key elements of proinflammatory signalling". Seminars in Immunology. 12 (1): 85–98. doi:10.1006/smim.2000.0210. PMID   10723801.
19. Ermolaeva MA, Dakhovnik A, Schumacher B (Jan 2015). "Quality control mechanisms in cellular and systemic DNA damage responses". Ageing Research Reviews. 23 (Pt A): 3–11. doi:10.1016/j.arr.2014.12.009. PMC   4886828 . PMID   25560147.
20. Checler F, da Costa CA, Ancolio K, Chevallier N, Lopez-Perez E, Marambaud P (Jul 2000). "Role of the proteasome in Alzheimer's disease". Biochimica et Biophysica Acta (BBA) - Molecular Basis of Disease. 1502 (1): 133–8. doi: 10.1016/s0925-4439(00)00039-9 . PMID   10899438.
21. Chung KK, Dawson VL, Dawson TM (Nov 2001). "The role of the ubiquitin-proteasomal pathway in Parkinson's disease and other neurodegenerative disorders". Trends in Neurosciences. 24 (11 Suppl): S7–14. doi:10.1016/s0166-2236(00)01998-6. PMID   11881748. S2CID   2211658.
22. Ikeda, Kenji; Akiyama, Haruhiko; Arai, Tetsuaki; Ueno, Hideki; Tsuchiya, Kuniaki; Kosaka, Kenji (2002). "Morphometrical reappraisal of motor neuron system of Pick's disease and amyotrophic lateral sclerosis with dementia". Acta Neuropathologica. 104 (1): 21–28. doi:10.1007/s00401-001-0513-5. ISSN   0001-6322. PMID   12070660. S2CID   22396490.
23. Manaka H, Kato T, Kurita K, Katagiri T, Shikama Y, Kujirai K, Kawanami T, Suzuki Y, Nihei K, Sasaki H (May 1992). "Marked increase in cerebrospinal fluid ubiquitin in Creutzfeldt–Jakob disease". Neuroscience Letters. 139 (1): 47–9. doi:10.1016/0304-3940(92)90854-z. PMID   1328965. S2CID   28190967.
24. Mathews KD, Moore SA (Jan 2003). "Limb-girdle muscular dystrophy". Current Neurology and Neuroscience Reports. 3 (1): 78–85. doi:10.1007/s11910-003-0042-9. PMID   12507416. S2CID   5780576.
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26. Calise J, Powell SR (Feb 2013). "The ubiquitin proteasome system and myocardial ischemia". American Journal of Physiology. Heart and Circulatory Physiology. 304 (3): H337–49. doi:10.1152/ajpheart.00604.2012. PMC   3774499 . PMID   23220331.
27. Predmore JM, Wang P, Davis F, Bartolone S, Westfall MV, Dyke DB, Pagani F, Powell SR, Day SM (Mar 2010). "Ubiquitin proteasome dysfunction in human hypertrophic and dilated cardiomyopathies". Circulation. 121 (8): 997–1004. doi:10.1161/CIRCULATIONAHA.109.904557. PMC   2857348 . PMID   20159828.
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31. Egerer K, Kuckelkorn U, Rudolph PE, Rückert JC, Dörner T, Burmester GR, Kloetzel PM, Feist E (Oct 2002). "Circulating proteasomes are markers of cell damage and immunologic activity in autoimmune diseases". The Journal of Rheumatology. 29 (10): 2045–52. PMID   12375310.
32. Yamauchi J, Sekiguchi M, Shirai T, Yamada M, Ishimi Y (2013). "Role of nuclear localization of PSMB1 in transcriptional activation". Bioscience, Biotechnology, and Biochemistry. 77 (8): 1785–7. doi: 10.1271/bbb.130290 . PMID   23924720.
33. Singh V, Sharma V, Verma V, Pandey D, Yadav SK, Maikhuri JP, Gupta G (Nov 2014). "Apigenin manipulates the ubiquitin-proteasome system to rescue estrogen receptor-β from degradation and induce apoptosis in prostate cancer cells". European Journal of Nutrition. 54 (8): 1255–67. doi:10.1007/s00394-014-0803-z. PMID   25408199. S2CID   206969475.
34. Barton MK (Sep 2013). "Predictive biomarkers may help individualize treatment for patients with follicular lymphoma". CA: A Cancer Journal for Clinicians . 63 (5): 293–4. doi: 10.3322/caac.21197 . PMID   23842891. S2CID   37162376.
35. Feng L, Zhang D, Fan C, Ma C, Yang W, Meng Y, Wu W, Guan S, Jiang B, Yang M, Liu X, Guo D (11 July 2013). "ER stress-mediated apoptosis induced by celastrol in cancer cells and important role of glycogen synthase kinase-3β in the signal network". Cell Death & Disease. 4 (7): e715. doi:10.1038/cddis.2013.222. PMC   3730400 . PMID   23846217.
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Further reading

• Coux O, Tanaka K, Goldberg AL (1996). "Structure and functions of the 20S and 26S proteasomes". Annual Review of Biochemistry. 65: 801–47. doi:10.1146/annurev.bi.65.070196.004101. PMID   8811196.
• Goff SP (Aug 2003). "Death by deamination: a novel host restriction system for HIV-1". Cell. 114 (3): 281–3. doi: 10.1016/S0092-8674(03)00602-0 . PMID   12914693. S2CID   16340355.
• Lee LW, Moomaw CR, Orth K, McGuire MJ, DeMartino GN, Slaughter CA (Feb 1990). "Relationships among the subunits of the high molecular weight proteinase, macropain (proteasome)". Biochimica et Biophysica Acta (BBA) - Protein Structure and Molecular Enzymology. 1037 (2): 178–85. doi:10.1016/0167-4838(90)90165-C. PMID   2306472.
• Okumura K, Nogami M, Taguchi H, Hisamatsu H, Tanaka K (May 1995). "The genes for the alpha-type HC3 (PMSA2) and beta-type HC5 (PMSB1) subunits of human proteasomes map to chromosomes 6q27 and 7p12-p13 by fluorescence in situ hybridization". Genomics. 27 (2): 377–9. doi:10.1006/geno.1995.1062. PMID   7558012.
• Kristensen P, Johnsen AH, Uerkvitz W, Tanaka K, Hendil KB (Dec 1994). "Human proteasome subunits from 2-dimensional gels identified by partial sequencing". Biochemical and Biophysical Research Communications. 205 (3): 1785–9. doi:10.1006/bbrc.1994.2876. PMID   7811265.
• Tamura T, Osaka F, Kawamura Y, Higuti T, Ishida N, Nothwang HG, Tsurumi C, Tanaka K, Ichihara A (Nov 1994). "Isolation and characterization of alpha-type HC3 and beta-type HC5 subunit genes of human proteasomes". Journal of Molecular Biology. 244 (1): 117–24. doi:10.1006/jmbi.1994.1710. PMID   7966316.
• Maruyama K, Sugano S (Jan 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.
• Seeger M, Ferrell K, Frank R, Dubiel W (Mar 1997). "HIV-1 tat inhibits the 20 S proteasome and its 11 S regulator-mediated activation". The Journal of Biological Chemistry. 272 (13): 8145–8. doi: 10.1074/jbc.272.13.8145 . PMID   9079628.
• Suzuki Y, Yoshitomo-Nakagawa K, Maruyama K, Suyama A, Sugano S (Oct 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.
• Madani N, Kabat D (Dec 1998). "An endogenous inhibitor of human immunodeficiency virus in human lymphocytes is overcome by the viral Vif protein". Journal of Virology. 72 (12): 10251–5. doi:10.1128/JVI.72.12.10251-10255.1998. PMC   110608 . PMID   9811770.
• Simon JH, Gaddis NC, Fouchier RA, Malim MH (Dec 1998). "Evidence for a newly discovered cellular anti-HIV-1 phenotype". Nature Medicine. 4 (12): 1397–400. doi:10.1038/3987. PMID   9846577. S2CID   25235070.
• Elenich LA, Nandi D, Kent AE, McCluskey TS, Cruz M, Iyer MN, Woodward EC, Conn CW, Ochoa AL, Ginsburg DB, Monaco JJ (Sep 1999). "The complete primary structure of mouse 20S proteasomes". Immunogenetics. 49 (10): 835–42. doi:10.1007/s002510050562. PMID   10436176. S2CID   20977116.
• Mulder LC, Muesing MA (Sep 2000). "Degradation of HIV-1 integrase by the N-end rule pathway". The Journal of Biological Chemistry. 275 (38): 29749–53. doi: 10.1074/jbc.M004670200 . PMID   10893419.
• Feng Y, Longo DL, Ferris DK (Jan 2001). "Polo-like kinase interacts with proteasomes and regulates their activity". Cell Growth & Differentiation. 12 (1): 29–37. PMID   11205743.
• Sheehy AM, Gaddis NC, Choi JD, Malim MH (Aug 2002). "Isolation of a human gene that inhibits HIV-1 infection and is suppressed by the viral Vif protein". Nature. 418 (6898): 646–50. Bibcode:2002Natur.418..646S. doi:10.1038/nature00939. PMID   12167863. S2CID   4403228.
• Huang X, Seifert U, Salzmann U, Henklein P, Preissner R, Henke W, Sijts AJ, Kloetzel PM, Dubiel W (Nov 2002). "The RTP site shared by the HIV-1 Tat protein and the 11S regulator subunit alpha is crucial for their effects on proteasome function including antigen processing". Journal of Molecular Biology. 323 (4): 771–82. doi:10.1016/S0022-2836(02)00998-1. PMID   12419264.
• Suzumori N, Burns KH, Yan W, Matzuk MM (Jan 2003). "RFPL4 interacts with oocyte proteins of the ubiquitin-proteasome degradation pathway". Proceedings of the National Academy of Sciences of the United States of America. 100 (2): 550–5. Bibcode:2003PNAS..100..550S. doi: 10.1073/pnas.0234474100 . PMC   141033 . PMID   12525704.