PSMA4

PSMA4
Available structures
PDBOrtholog search: PDBe RCSB
Identifiers
Aliases PSMA4, HC9, HsT17706, PSC9, proteasome subunit alpha 4
External IDs MGI: 1347060 HomoloGene: 2083 GeneCards: PSMA4
Genetically Related Diseases
rheumatoid arthritis[1]
RNA expression pattern
More reference expression data
Orthologs
Species Human Mouse
Entrez

5685

26441

Ensembl

ENSG00000041357

ENSMUSG00000032301

UniProt

P25789

Q9R1P0

RefSeq (mRNA)

NM_002789
NM_001102667
NM_001102668

NM_011966

RefSeq (protein)

NP_001096137.1
NP_001096138.1
NP_002780.1

NP_036096.1

Location (UCSC) Chr 15: 78.54 – 78.55 Mb Chr 9: 54.95 – 54.96 Mb
PubMed search [2] [3]
Wikidata
View/Edit HumanView/Edit Mouse

Proteasome subunit alpha type-4 also known as macropain subunit C9, proteasome component C9, and 20S proteasome subunit alpha-3 is a protein that in humans is encoded by the PSMA4 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.

Structure

Protein expression

The PSMA4 gene encodes a member of the peptidase T1A family, that is a 20S core alpha subunit.[5] The gene has 9 exons and locates at chromosome band 15q25.1. The human protein proteasome subunit alpha type-4 is 29.5 kDa in size and composed of 261 amino acids. The calculated theoretical pI of this protein is 7.58.

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

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.[8][9] 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]

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. As a component of alpha ring, proteasome subunit alpha type-4 contributes to the formation of heptameric alpha rings and substrate entrance gate. Importantly, this subunit plays an critical role in the assembly of 19S base and 20S. In a study using Saccharomyces cerevisiae proteasome core particle 20S and regulatory particle 19S (similar to human proteasome) base component to delineate the binding process between 19S and 20S, evidences showed that one 19S subunit, Rpt6, can insert its tail into the pocket formed by alpha2 and alpha3 subunit (based on systematic nomenclature), facilitating the complex formation between 20S and 19S base component.[11]

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) [12] 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.[13] 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,[14][15] cardiovascular diseases,[16][17][18] inflammatory responses and autoimmune diseases,[19] and systemic DNA damage responses leading to malignancies.[20]

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,[21] Parkinson's disease[22] and Pick's disease,[23] Amyotrophic lateral sclerosis (ALS),[23] Huntington's disease,[22] Creutzfeldt–Jakob disease,[24] and motor neuron diseases, polyglutamine (PolyQ) diseases, Muscular dystrophies[25] and several rare forms of neurodegenerative diseases associated with dementia.[26] As part of the Ubiquitin-Proteasome System (UPS), the proteasome maintains cardiac protein homeostasis and thus plays a significant role in cardiac Ischemic injury,[27] ventricular hypertrophy[28] and Heart failure.[29] 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.[30] 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 selectine) and prostaglandins and nitric oxide (NO).[31] 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.[32] Lastly, autoimmune disease patients with SLE, Sjogren's syndrome and rheumatoid arthritis (RA) predominantly exhibit circulating proteasomes which can be applied as clinical biomarkers.[33]

As genetic factors play an crucial role in the predisposition to cancer, genome-wide association studies (GWAS) have linked the chromosome 15q25.1 locus to the susceptibility of lung cancer and implicated the proteasome subunit alpha type-4 (PMSA4) as a candidate gene. A case-control study in lung cancer patients and controls in the Chinese Han population was investigated and suggested an association between PSMA4 and lung cancer.[34] Furthermore, PMSA4 has also been implicated to be involved in the pathogenesis of ankylosing spondylitis (AS) and may therefore be a potential biomarker for clinical applications in AS.[35]

Interactions

PSMA4 has been shown to interact with PLK1.[36]

References

  1. "Diseases that are genetically associated with PSMA4 view/edit references on wikidata".
  2. "Human PubMed Reference:".
  3. "Mouse PubMed Reference:".
  4. Tamura T, Lee DH, Osaka F, Fujiwara T, Shin S, Chung CH, Tanaka K, Ichihara A (Jun 1991). "Molecular cloning and sequence analysis of cDNAs for five major subunits of human proteasomes (multi-catalytic proteinase complexes)". Biochim Biophys Acta. 1089 (1): 95–102. doi:10.1016/0167-4781(91)90090-9. PMID 2025653.
  5. "Entrez Gene: PSMA4 proteasome (prosome, macropain) subunit, alpha type, 4".
  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. 1 2 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 3827779Freely accessible. 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.
  9. 1 2 Groll M, Bajorek M, Köhler A, Moroder L, Rubin DM, Huber R, Glickman MH, Finley D (Nov 2000). "A gated channel into the proteasome core particle". Nature Structural Biology. 7 (11): 1062–7. doi:10.1038/80992. PMID 11062564.
  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. Park S, Li X, Kim HM, Singh CR, Tian G, Hoyt MA, Lovell S, Battaile KP, Zolkiewski M, Coffino P, Roelofs J, Cheng Y, Finley D (May 2013). "Reconfiguration of the proteasome during chaperone-mediated assembly". Nature. 497 (7450): 512–6. Bibcode:2013Natur.497..512P. doi:10.1038/nature12123. PMC 3687086Freely accessible. PMID 23644457.
  12. 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 4037451Freely accessible. PMID 24457024.
  13. Goldberg, AL; Stein, R; Adams, J (August 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.
  14. Sulistio YA, Heese K (Jan 2015). "The Ubiquitin-Proteasome System and Molecular Chaperone Deregulation in Alzheimer's Disease". Molecular Neurobiology. doi:10.1007/s12035-014-9063-4. PMID 25561438.
  15. 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 4179678Freely accessible. PMID 25324717.
  16. 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 4011959Freely accessible. PMID 24380730.
  17. 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 4241867Freely accessible. PMID 25133688.
  18. 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 4317573Freely accessible. PMID 25651176.
  19. Karin, M; Delhase, M (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.
  20. 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. PMID 25560147.
  21. Checler, F; da Costa, CA; Ancolio, K; Chevallier, N; Lopez-Perez, E; Marambaud, P (26 July 2000). "Role of the proteasome in Alzheimer's disease.". Biochimica et Biophysica Acta. 1502 (1): 133–8. doi:10.1016/s0925-4439(00)00039-9. PMID 10899438.
  22. 1 2 Chung, KK; Dawson, VL; Dawson, TM (November 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.
  23. 1 2 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.
  24. Manaka, H; Kato, T; Kurita, K; Katagiri, T; Shikama, Y; Kujirai, K; Kawanami, T; Suzuki, Y; Nihei, K; Sasaki, H (11 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.
  25. Mathews, KD; Moore, SA (January 2003). "Limb-girdle muscular dystrophy.". Current neurology and neuroscience reports. 3 (1): 78–85. doi:10.1007/s11910-003-0042-9. PMID 12507416.
  26. Mayer, RJ (March 2003). "From neurodegeneration to neurohomeostasis: the role of ubiquitin.". Drug news & perspectives. 16 (2): 103–8. doi:10.1358/dnp.2003.16.2.829327. PMID 12792671.
  27. Calise, J; Powell, S. R. (2013). "The ubiquitin proteasome system and myocardial ischemia". AJP: Heart and Circulatory Physiology. 304 (3): H337–49. doi:10.1152/ajpheart.00604.2012. PMC 3774499Freely accessible. PMID 23220331.
  28. Predmore, JM; Wang, P; Davis, F; Bartolone, S; Westfall, MV; Dyke, DB; Pagani, F; Powell, SR; Day, SM (2 March 2010). "Ubiquitin proteasome dysfunction in human hypertrophic and dilated cardiomyopathies.". Circulation. 121 (8): 997–1004. doi:10.1161/circulationaha.109.904557. PMC 2857348Freely accessible. PMID 20159828.
  29. Powell, SR (July 2006). "The ubiquitin-proteasome system in cardiac physiology and pathology". American Journal of Physiology. Heart and Circulatory Physiology. 291 (1): H1–H19. doi:10.1152/ajpheart.00062.2006. PMID 16501026.
  30. Adams, J (1 April 2003). "Potential for proteasome inhibition in the treatment of cancer.". Drug Discovery Today. 8 (7): 307–15. doi:10.1016/s1359-6446(03)02647-3. PMID 12654543.
  31. Karin, M; Delhase, M (February 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.
  32. Ben-Neriah, Y (January 2002). "Regulatory functions of ubiquitination in the immune system". Nature Immunology. 3 (1): 20–6. doi:10.1038/ni0102-20. PMID 11753406.
  33. Egerer, K; Kuckelkorn, U; Rudolph, PE; Rückert, JC; Dörner, T; Burmester, GR; Kloetzel, PM; Feist, E (October 2002). "Circulating proteasomes are markers of cell damage and immunologic activity in autoimmune diseases.". The Journal of rheumatology. 29 (10): 2045–52. PMID 12375310.
  34. Wang, T; Chen, T; Thakur, A; Liang, Y; Gao, L; Zhang, S; Tian, Y; Jin, T; Liu, JJ; Chen, M (6 March 2015). "Association of PSMA4 polymorphisms with lung cancer susceptibility and response to cisplatin-based chemotherapy in a Chinese Han population". Clinical & Translational Oncology. 17 (7): 564–9. doi:10.1007/s12094-015-1279-x. PMID 25744645.
  35. Zhao, H; Wang, D; Fu, D; Xue, L (29 November 2014). "Predicting the potential ankylosing spondylitis-related genes utilizing bioinformatics approaches". Rheumatology international. 35 (6): 973–9. doi:10.1007/s00296-014-3178-9. PMID 25432079.
  36. Feng Y, Longo DL, Ferris DK (Jan 2001). "Polo-like kinase interacts with proteasomes and regulates their activity". Cell Growth Differ. 12 (1): 29–37. PMID 11205743.

Further reading

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