151
|
Gomes AV. Genetics of proteasome diseases. SCIENTIFICA 2013; 2013:637629. [PMID: 24490108 PMCID: PMC3892944 DOI: 10.1155/2013/637629] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2013] [Accepted: 11/18/2013] [Indexed: 05/28/2023]
Abstract
The proteasome is a large, multiple subunit complex that is capable of degrading most intracellular proteins. Polymorphisms in proteasome subunits are associated with cardiovascular diseases, diabetes, neurological diseases, and cancer. One polymorphism in the proteasome gene PSMA6 (-8C/G) is associated with three different diseases: type 2 diabetes, myocardial infarction, and coronary artery disease. One type of proteasome, the immunoproteasome, which contains inducible catalytic subunits, is adapted to generate peptides for antigen presentation. It has recently been shown that mutations and polymorphisms in the immunoproteasome catalytic subunit PSMB8 are associated with several inflammatory and autoinflammatory diseases including Nakajo-Nishimura syndrome, CANDLE syndrome, and intestinal M. tuberculosis infection. This comprehensive review describes the disease-related polymorphisms in proteasome genes associated with human diseases and the physiological modulation of proteasome function by these polymorphisms. Given the large number of subunits and the central importance of the proteasome in human physiology as well as the fast pace of detection of proteasome polymorphisms associated with human diseases, it is likely that other polymorphisms in proteasome genes associated with diseases will be detected in the near future. While disease-associated polymorphisms are now readily discovered, the challenge will be to use this genetic information for clinical benefit.
Collapse
Affiliation(s)
- Aldrin V. Gomes
- Department of Neurobiology, Physiology, and Behavior, University of California, Davis, CA 95616, USA
- Department of Physiology and Membrane Biology, University of California, Davis, CA 95616, USA
| |
Collapse
|
152
|
Demasi M, Netto LE, Silva GM, Hand A, de Oliveira CL, Bicev RN, Gozzo F, Barros MH, Leme JM, Ohara E. Redox regulation of the proteasome via S-glutathionylation. Redox Biol 2013; 2:44-51. [PMID: 24396728 PMCID: PMC3881202 DOI: 10.1016/j.redox.2013.12.003] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2013] [Revised: 12/04/2013] [Accepted: 12/05/2013] [Indexed: 12/13/2022] Open
Abstract
The proteasome is a multimeric and multicatalytic intracellular protease responsible for the degradation of proteins involved in cell cycle control, various signaling processes, antigen presentation, and control of protein synthesis. The central catalytic complex of the proteasome is called the 20S core particle. The majority of these are flanked on one or both sides by regulatory units. Most common among these units is the 19S regulatory unit. When coupled to the 19S unit, the complex is termed the asymmetric or symmetric 26S proteasome depending on whether one or both sides are coupled to the 19S unit, respectively. The 26S proteasome recognizes poly-ubiquitinylated substrates targeted for proteolysis. Targeted proteins interact with the 19S unit where they are deubiquitinylated, unfolded, and translocated to the 20S catalytic chamber for degradation. The 26S proteasome is responsible for the degradation of major proteins involved in the regulation of the cellular cycle, antigen presentation and control of protein synthesis. Alternatively, the proteasome is also active when dissociated from regulatory units. This free pool of 20S proteasome is described in yeast to mammalian cells. The free 20S proteasome degrades proteins by a process independent of poly-ubiquitinylation and ATP consumption. Oxidatively modified proteins and other substrates are degraded in this manner. The 20S proteasome comprises two central heptamers (β-rings) where the catalytic sites are located and two external heptamers (α-rings) that are responsible for proteasomal gating. Because the 20S proteasome lacks regulatory units, it is unclear what mechanisms regulate the gating of α-rings between open and closed forms. In the present review, we discuss 20S proteasomal gating modulation through a redox mechanism, namely, S-glutathionylation of cysteine residues located in the α-rings, and the consequence of this post-translational modification on 20S proteasomal function.
Collapse
Affiliation(s)
- Marilene Demasi
- Laboratório de Bioquímica e Biofísica, Instituto Butantan, São Paulo, SP, Brazil
| | - Luis E.S. Netto
- Departamento de Genética e Biologia Evolutiva, IB-Universidade de São Paulo, São Paulo, SP, Brazil
| | - Gustavo M. Silva
- Laboratório de Bioquímica e Biofísica, Instituto Butantan, São Paulo, SP, Brazil
- Departamento de Genética e Biologia Evolutiva, IB-Universidade de São Paulo, São Paulo, SP, Brazil
| | - Adrian Hand
- Laboratório de Bioquímica e Biofísica, Instituto Butantan, São Paulo, SP, Brazil
| | | | - Renata N. Bicev
- Departamento de Física Experimental, IF-Universidade de São Paulo, São Paulo, SP, Brazil
| | - Fabio Gozzo
- Instituto de Química, UNICAMP, Campinas, SP, Brazil
| | - Mario H. Barros
- Departamento de Microbiologia, ICB-Universidade de São Paulo, São Paulo, SP, Brazil
| | - Janaina M.M. Leme
- Laboratório de Bioquímica e Biofísica, Instituto Butantan, São Paulo, SP, Brazil
- Departamento de Genética e Biologia Evolutiva, IB-Universidade de São Paulo, São Paulo, SP, Brazil
| | - Erina Ohara
- Laboratório de Bioquímica e Biofísica, Instituto Butantan, São Paulo, SP, Brazil
| |
Collapse
|
153
|
Halbach F, Reichelt P, Rode M, Conti E. The yeast ski complex: crystal structure and RNA channeling to the exosome complex. Cell 2013; 154:814-26. [PMID: 23953113 DOI: 10.1016/j.cell.2013.07.017] [Citation(s) in RCA: 125] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2012] [Revised: 05/13/2013] [Accepted: 07/12/2013] [Indexed: 10/26/2022]
Abstract
The Ski complex is a conserved multiprotein assembly required for the cytoplasmic functions of the exosome, including RNA turnover, surveillance, and interference. Ski2, Ski3, and Ski8 assemble in a tetramer with 1:1:2 stoichiometry. The crystal structure of an S. cerevisiae 370 kDa core complex shows that Ski3 forms an array of 33 TPR motifs organized in N-terminal and C-terminal arms. The C-terminal arm of Ski3 and the two Ski8 subunits position the helicase core of Ski2 centrally within the complex, enhancing RNA binding. The Ski3 N-terminal arm and the Ski2 insertion domain allosterically modulate the ATPase and helicase activities of the complex. Biochemical data suggest that the Ski complex can thread RNAs directly to the exosome, coupling the helicase and the exoribonuclease through a continuous RNA channel. Finally, we identify a Ski8-binding motif common to Ski3 and Spo11, rationalizing the moonlighting properties of Ski8 in mRNA decay and meiosis.
Collapse
Affiliation(s)
- Felix Halbach
- Department of Structural Cell Biology, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried/Munich, Germany
| | | | | | | |
Collapse
|
154
|
The C-terminal residues of Saccharomyces cerevisiae Mec1 are required for its localization, stability, and function. G3-GENES GENOMES GENETICS 2013; 3:1661-74. [PMID: 23934994 PMCID: PMC3789791 DOI: 10.1534/g3.113.006841] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Mec1, a member of the phosphoinositide three-kinase-related kinase (PIKK) family of proteins, is involved in the response to replicative stress and DNA damage and in telomere maintenance. An essential 30 to 35 residue, the FATC domain is found at the C-terminus of all PIKK family members. To investigate the roles of the C-terminal residues of Mec1, we characterized alleles of Saccharomyces cerevisiae mec1 that alter the FATC domain. A change of the terminal tryptophan to alanine resulted in temperature-sensitive growth, sensitivity to hydroxyurea, and diminished kinase activity in vitro. Addition of a terminal glycine or deletion of one, two, or three residues resulted in loss of cell viability and kinase function. Each of these Mec1 derivatives was less stable than wild-type Mec1, eluted abnormally from a size exclusion column, and showed reduced nuclear localization. We identified rpn3-L140P, which encodes a component of the 19S proteasomal regulatory particle of the 26S proteasome, as a suppressor of the temperature-sensitive growth caused by mec1-W2368A. The rpn3-L140P allele acted in a partially dominant fashion. It was not able to suppress the inviability of the C-terminal truncations or additions or the hydroxyurea sensitivity of mec1-W2368A. The rpn3-L140P allele restored Mec1-W2368A to nearly wild-type protein levels at 37°, an effect partially mimicked by the proteasome inhibitor MG-132. Our study supports a role for the C-terminus in Mec1 folding and stability, and suggests a role for the proteasome in regulating Mec1 levels.
Collapse
|
155
|
Tomaić V, Ganti K, Pim D, Bauer C, Blattner C, Banks L. Interaction of HPV E6 oncoproteins with specific proteasomal subunits. Virology 2013; 446:389-96. [PMID: 24074603 DOI: 10.1016/j.virol.2013.08.016] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2013] [Revised: 04/25/2013] [Accepted: 08/14/2013] [Indexed: 10/26/2022]
Abstract
The Human Papillomavirus E6 oncoproteins have the capacity to target several of their cellular interacting partners for proteasome mediated degradation, and recent proteomic analyses suggest a close involvement of E6 with the cellular proteasome machinery. In this study we have performed an extensive analysis of the capacity of different E6 oncoproteins to interact with specific proteasome components. We demonstrate that multiple subunits of the proteasome can be bound by different HPV E6 oncoproteins. Furthermore, whilst most of these interactions appear independent of the E6AP ubiquitin ligase, the association of E6 with the major ubiquitin-accepting proteasome subunit, S5a, does require the presence of E6AP. One consequence of the interaction between E6/E6AP and S5a is enhanced ubiquitination of this proteasome subunit. These results suggest a complex interplay between E6 and the proteasome, only some aspects of which are dependent upon the E6AP ubiquitin ligase.
Collapse
Affiliation(s)
- Vjekoslav Tomaić
- International Centre for Genetic Engineering and Biotechnology, Padriciano 99, I-34149 Trieste, Italy
| | | | | | | | | | | |
Collapse
|
156
|
Förster F, Unverdorben P, Śledź P, Baumeister W. Unveiling the Long-Held Secrets of the 26S Proteasome. Structure 2013; 21:1551-62. [DOI: 10.1016/j.str.2013.08.010] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2013] [Revised: 08/15/2013] [Accepted: 08/16/2013] [Indexed: 01/23/2023]
|
157
|
The RNA exosome and proteasome: common principles of degradation control. Nat Rev Mol Cell Biol 2013; 14:654-60. [PMID: 23989960 DOI: 10.1038/nrm3657] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Defective RNAs and proteins are swiftly degraded by cellular quality control mechanisms. A large fraction of their degradation is mediated by the exosome and the proteasome. These complexes have a similar architectural framework based on cylindrical, hollow structures that are conserved from bacteria and archaea to eukaryotes. Mechanistic similarities have also been identified for how RNAs and proteins are channelled into these structures and prepared for degradation. Insights gained from studies of the proteasome should now set the stage for elucidating the regulation, assembly and small-molecule inhibition of the exosome.
Collapse
|
158
|
Ehlinger A, Walters KJ. Structural insights into proteasome activation by the 19S regulatory particle. Biochemistry 2013; 52:3618-28. [PMID: 23672618 DOI: 10.1021/bi400417a] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Since its discovery in the late 1970s, the ubiquitin-proteasome system (UPS) has become recognized as the major pathway for regulated cellular proteolysis. Processes such as cell cycle control, pathogen resistance, and protein quality control rely on selective protein degradation at the proteasome for homeostatic function. Perhaps as a consequence of the importance of this pathway, and the genesis of severe diseases upon its dysregulation, protein degradation by the UPS is highly controlled from the level of substrate recognition to proteolysis. Technological advances over the past decade have created an explosion of structural and mechanistic information that has underscored the complexity of the proteasome and its upstream regulatory factors. Significant insights have come from the study of the 19S proteasome regulatory particle (RP) responsible for recognition and processing of ubiquitinated substrates destined for proteolysis. Established as a highly dynamic proteasome activator, the RP has a large number of both permanent and transient components with specialized functional roles that are critical for proteasome function. In this review, we highlight recent mechanistic developments in the study of proteasome activation by the RP and how they provide context to our current understanding of the UPS.
Collapse
Affiliation(s)
- Aaron Ehlinger
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota , Minneapolis, Minnesota 55455, United States
| | | |
Collapse
|
159
|
Reconfiguration of the proteasome during chaperone-mediated assembly. Nature 2013; 497:512-6. [PMID: 23644457 PMCID: PMC3687086 DOI: 10.1038/nature12123] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2012] [Accepted: 03/27/2013] [Indexed: 01/18/2023]
Abstract
The proteasomal ATPase ring, comprising Rpt1-Rpt6, associates with the heptameric α-ring of the proteasome core particle (CP) in the mature proteasome, with the Rpt carboxy-terminal tails inserting into pockets of the α-ring. Rpt ring assembly is mediated by four chaperones, each binding a distinct Rpt subunit. Here we report that the base subassembly of the Saccharomyces cerevisiae proteasome, which includes the Rpt ring, forms a high-affinity complex with the CP. This complex is subject to active dissociation by the chaperones Hsm3, Nas6 and Rpn14. Chaperone-mediated dissociation was abrogated by a non-hydrolysable ATP analogue, indicating that chaperone action is coupled to nucleotide hydrolysis by the Rpt ring. Unexpectedly, synthetic Rpt tail peptides bound α-pockets with poor specificity, except for Rpt6, which uniquely bound the α2/α3-pocket. Although the Rpt6 tail is not visualized within an α-pocket in mature proteasomes, it inserts into the α2/α3-pocket in the base-CP complex and is important for complex formation. Thus, the Rpt-CP interface is reconfigured when the lid complex joins the nascent proteasome to form the mature holoenzyme.
Collapse
|
160
|
Radha GV, Rani TS, Sarvani B. A review on proniosomal drug delivery system for targeted drug action. J Basic Clin Pharm 2013; 4:42-8. [PMID: 24808669 PMCID: PMC3979263 DOI: 10.4103/0976-0105.113609] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Proniosomes are dry formulation of water soluble carrier particles that are coated with surfactant. They are rehydrated to form niosomal dispersion immediately before use on agitation in hot aqueous media within minutes. Proniosomes are physically stable during the storage and transport. Drug encapsulated in the vesicular structure of proniosomes prolong the existence of drug in the systematic circulation and enhances the penetration into target tissue and reduce toxicity. From a technical point of view, niosomes are promising drug carriers as they possess greater chemical stability and lack of many disadvantages associated with liposomes, such as high- cost and variable purity problems of phospholipids. The present review emphasizes on overall methods of preparation characterization and applicability of proniosomes in targeted drug action.
Collapse
Affiliation(s)
- G. V. Radha
- Department of Pharmaceutics, Gandhi Institute of Technology and Management, Institute of Pharmacy, Gandhi Institute of Technology and Management University, Rushikonda, Visakhapatnam, Andhra Pradesh, India
| | - T. Sudha Rani
- Department of Pharmaceutics, Gandhi Institute of Technology and Management, Institute of Pharmacy, Gandhi Institute of Technology and Management University, Rushikonda, Visakhapatnam, Andhra Pradesh, India
| | - B. Sarvani
- Department of Pharmaceutics, Gandhi Institute of Technology and Management, Institute of Pharmacy, Gandhi Institute of Technology and Management University, Rushikonda, Visakhapatnam, Andhra Pradesh, India
| |
Collapse
|