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McDonald EF, Meiler J, Plate L. CFTR Folding: From Structure and Proteostasis to Cystic Fibrosis Personalized Medicine. ACS Chem Biol 2023; 18:2128-2143. [PMID: 37730207 PMCID: PMC10595991 DOI: 10.1021/acschembio.3c00310] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Accepted: 08/02/2023] [Indexed: 09/22/2023]
Abstract
Cystic fibrosis (CF) is a lethal genetic disease caused by mutations in the chloride ion channel cystic fibrosis transmembrane conductance regulator (CFTR). Class-II mutants of CFTR lack intermolecular interactions important for CFTR structural stability and lead to misfolding. Misfolded CFTR is detected by a diverse suite of proteostasis factors that preferentially bind and route mutant CFTR toward premature degradation, resulting in reduced plasma membrane CFTR levels and impaired chloride ion conductance associated with CF. CF treatment has been vastly improved over the past decade by the availability of small molecules called correctors. Correctors directly bind CFTR, stabilize its structure by conferring thermodynamically favorable interactions that compensate for mutations, and thereby lead to downstream folding fidelity. However, each of over 100 Class-II CF causing mutations causes unique structural defects and shows a unique response to drug treatment, described as theratype. Understanding CFTR structural defects, the proteostasis factors evaluating those defects, and the stabilizing effects of CFTR correctors will illuminate a path toward personalized medicine for CF. Here, we review recent advances in our understanding of CFTR folding, focusing on structure, corrector binding sites, the mechanisms of proteostasis factors that evaluate CFTR, and the implications for CF personalized medicine.
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Affiliation(s)
- Eli Fritz McDonald
- Department
of Chemistry, Vanderbilt University, Nashville, Tennessee 37235, United States
- Center
for Structural Biology, Vanderbilt University, Nashville, Tennessee 37240, United States
| | - Jens Meiler
- Department
of Chemistry, Vanderbilt University, Nashville, Tennessee 37235, United States
- Center
for Structural Biology, Vanderbilt University, Nashville, Tennessee 37240, United States
- Department
of Pharmacology, Vanderbilt University, Nashville, Tennessee 37240, United States
- Institute
for Drug Discovery, Leipzig University, Leipzig, SAC 04103, Germany
| | - Lars Plate
- Department
of Chemistry, Vanderbilt University, Nashville, Tennessee 37235, United States
- Department
of Biological Sciences, Vanderbilt University, Nashville, Tennessee 37235, United States
- Department
of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
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2
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Alharbi BM, Albinhassan TH, Alzahrani RA, Bouchama A, Mohammad S, Alomari AA, Bin-Jumah MN, AlSuhaibani ES, Malik SS. Profiling the Hsp70 Chaperone Network in Heat-Induced Proteotoxic Stress Models of Human Neurons. BIOLOGY 2023; 12:416. [PMID: 36979108 PMCID: PMC10045125 DOI: 10.3390/biology12030416] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Revised: 02/28/2023] [Accepted: 03/06/2023] [Indexed: 03/12/2023]
Abstract
Heat stroke is among the most hazardous hyperthermia-related illnesses and an emerging threat to humans from climate change. Acute brain injury and long-lasting brain damage are the hallmarks of this condition. Hyperthermic neurological manifestations are remarkable for their damage correlation with stress amplitude and long-term persistence. Hyperthermia-induced protein unfolding, and nonspecific aggregation accumulation have neurotoxic effects and contribute to the pathogenesis of brain damage in heat stroke. Therefore, we generated heat-induced, dose-responsive extreme and mild proteotoxic stress models in medulloblastoma [Daoy] and neuroblastoma [SH-SY5Y] and differentiated SH-SY5Y neuronal cells. We show that heat-induced protein aggregation is associated with reduced cell proliferation and viability. Higher protein aggregation in differentiated neurons than in neuroblastoma precursors suggests a differential neuronal vulnerability to heat. We characterized the neuronal heat shock response through RT-PCR array analysis of eighty-four genes involved in protein folding and protein quality control (PQC). We identify seventeen significantly expressed genes, five of which are Hsp70 chaperones, and four of their known complementing function proteins. Protein expression analysis determined the individual differential contribution of the five Hsp70 chaperones to the proteotoxic stress response and the significance of only two members under mild conditions. The co-expression analysis reveals significantly high co-expression between the Hsp70 chaperones and their interacting partners. The findings of this study lend support to the hypothesis that hyperthermia-induced proteotoxicity may underlie the brain injury of heat stroke. Additionally, this study presents a comprehensive map of the Hsp70 network in these models with potential clinical and translational implications.
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Affiliation(s)
- Bothina Mohammed Alharbi
- Experimental Medicine Department, King Abdullah International Medical Research Center, King Saud bin Abdulaziz University for Health Sciences, Ministry of National Guard Health Affairs, Riyadh 11426, Saudi Arabia
| | - Tahani H. Albinhassan
- Zoology Department, College of Science, King Saud University, Riyadh 12372, Saudi Arabia
| | - Razan Ali Alzahrani
- Experimental Medicine Department, King Abdullah International Medical Research Center, King Saud bin Abdulaziz University for Health Sciences, Ministry of National Guard Health Affairs, Riyadh 11426, Saudi Arabia
| | - Abderrezak Bouchama
- Experimental Medicine Department, King Abdullah International Medical Research Center, King Saud bin Abdulaziz University for Health Sciences, Ministry of National Guard Health Affairs, Riyadh 11426, Saudi Arabia
| | - Sameer Mohammad
- Experimental Medicine Department, King Abdullah International Medical Research Center, King Saud bin Abdulaziz University for Health Sciences, Ministry of National Guard Health Affairs, Riyadh 11426, Saudi Arabia
| | - Awatif Abdulaziz Alomari
- Biology Department, College of Science, Princess Nourah bint Abdulrahman University, Riyadh 11564, Saudi Arabia
| | - May Nasser Bin-Jumah
- Biology Department, College of Science, Princess Nourah bint Abdulrahman University, Riyadh 11564, Saudi Arabia
| | | | - Shuja Shafi Malik
- Experimental Medicine Department, King Abdullah International Medical Research Center, King Saud bin Abdulaziz University for Health Sciences, Ministry of National Guard Health Affairs, Riyadh 11426, Saudi Arabia
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3
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Bracher A, Verghese J. Nucleotide Exchange Factors for Hsp70 Molecular Chaperones: GrpE, Hsp110/Grp170, HspBP1/Sil1, and BAG Domain Proteins. Subcell Biochem 2023; 101:1-39. [PMID: 36520302 DOI: 10.1007/978-3-031-14740-1_1] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Molecular chaperones of the Hsp70 family are key components of the cellular protein-folding machinery. Substrate folding is accomplished by iterative cycles of ATP binding, hydrolysis, and release. The ATPase activity of Hsp70 is regulated by two main classes of cochaperones: J-domain proteins stimulate ATPase hydrolysis by Hsp70, while nucleotide exchange factors (NEFs) facilitate the conversion from the ADP-bound to the ATP-bound state, thus closing the chaperone folding cycle. NEF function can additionally be antagonized by ADP dissociation inhibitors. Beginning with the discovery of the prototypical bacterial NEF, GrpE, a large diversity of nucleotide exchange factors for Hsp70 have been identified, connecting it to a multitude of cellular processes in the eukaryotic cell. Here we review recent advances toward structure and function of nucleotide exchange factors from the Hsp110/Grp170, HspBP1/Sil1, and BAG domain protein families and discuss how these cochaperones connect protein folding with cellular quality control and degradation pathways.
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Affiliation(s)
- Andreas Bracher
- Department of Cellular Biochemistry, Max-Planck-Institute of Biochemistry, Martinsried, Germany.
| | - Jacob Verghese
- Department of Cellular Biochemistry, Max-Planck-Institute of Biochemistry, Martinsried, Germany
- Trophic Communications GmbH, Munich, Germany
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4
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Gupta MK, Randhawa PK, Masternak MM. Role of BAG5 in Protein Quality Control: Double-Edged Sword? FRONTIERS IN AGING 2022; 3:844168. [PMID: 35821856 PMCID: PMC9261338 DOI: 10.3389/fragi.2022.844168] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/27/2021] [Accepted: 02/08/2022] [Indexed: 11/15/2022]
Abstract
Cardiovascular disorder is the major health burden and cause of death among individuals worldwide. As the cardiomyocytes lack the ability for self-renewal, it is utmost necessary to surveil the protein quality in the cells. The Bcl-2 associated anthanogene protein (BAG) family and molecular chaperones (HSP70, HSP90) actively participate in maintaining cellular protein quality control (PQC) to limit cellular dysfunction in the cells. The BAG family contains a unique BAG domain which facilitates their interaction with the ATPase domain of the heat shock protein 70 (HSP70) to assist in protein folding. Among the BAG family members (BAG1-6), BAG5 protein is unique since it has five domains in tandem, and the binding of BD5 induces certain conformational changes in the nucleotide-binding domain (NBD) of HSP70 such that it loses its affinity for binding to ADP and results in enhanced protein refolding activity of HSP70. In this review, we shall describe the role of BAG5 in modulating mitophagy, endoplasmic stress, and cellular viability. Also, we have highlighted the interaction of BAG5 with other proteins, including PINK, DJ-1, CHIP, and their role in cellular PQC. Apart from this, we have described the role of BAG5 in cellular metabolism and aging.
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5
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Strub MD, McCray, Jr. PB. Transcriptomic and Proteostasis Networks of CFTR and the Development of Small Molecule Modulators for the Treatment of Cystic Fibrosis Lung Disease. Genes (Basel) 2020; 11:genes11050546. [PMID: 32414011 PMCID: PMC7288469 DOI: 10.3390/genes11050546] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 05/07/2020] [Accepted: 05/08/2020] [Indexed: 12/18/2022] Open
Abstract
Cystic fibrosis (CF) is a lethal autosomal recessive disease caused by mutations in the CF transmembrane conductance regulator (CFTR) gene. The diversity of mutations and the multiple ways by which the protein is affected present challenges for therapeutic development. The observation that the Phe508del-CFTR mutant protein is temperature sensitive provided proof of principle that mutant CFTR could escape proteosomal degradation and retain partial function. Several specific protein interactors and quality control checkpoints encountered by CFTR during its proteostasis have been investigated for therapeutic purposes, but remain incompletely understood. Furthermore, pharmacological manipulation of many CFTR interactors has not been thoroughly investigated for the rescue of Phe508del-CFTR. However, high-throughput screening technologies helped identify several small molecule modulators that rescue CFTR from proteosomal degradation and restore partial function to the protein. Here, we discuss the current state of CFTR transcriptomic and biogenesis research and small molecule therapy development. We also review recent progress in CFTR proteostasis modulators and discuss how such treatments could complement current FDA-approved small molecules.
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Affiliation(s)
- Matthew D. Strub
- Interdisciplinary Graduate Program in Genetics, The University of Iowa, Iowa City, IA 52242, USA;
- Stead Family Department of Pediatrics, The University of Iowa, Iowa City, IA 52242, USA
| | - Paul B. McCray, Jr.
- Interdisciplinary Graduate Program in Genetics, The University of Iowa, Iowa City, IA 52242, USA;
- Stead Family Department of Pediatrics, The University of Iowa, Iowa City, IA 52242, USA
- Correspondence: ; Tel.: +1-(319)-335-6844
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Anglès F, Hutt DM, Balch WE. HDAC inhibitors rescue multiple disease-causing CFTR variants. Hum Mol Genet 2020; 28:1982-2000. [PMID: 30753450 DOI: 10.1093/hmg/ddz026] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Revised: 12/21/2018] [Accepted: 01/16/2019] [Indexed: 12/14/2022] Open
Abstract
Understanding the role of the epigenome in protein-misfolding diseases remains a challenge in light of genetic diversity found in the world-wide population revealed by human genome sequencing efforts and the highly variable response of the disease population to therapeutics. An ever-growing body of evidence has shown that histone deacetylase (HDAC) inhibitors (HDACi) can have significant benefit in correcting protein-misfolding diseases that occur in response to both familial and somatic mutation. Cystic fibrosis (CF) is a familial autosomal recessive disease, caused by genetic diversity in the CF transmembrane conductance regulator (CFTR) gene, a cyclic Adenosine MonoPhosphate (cAMP)-dependent chloride channel expressed at the apical plasma membrane of epithelial cells in multiple tissues. The potential utility of HDACi in correcting the phenylalanine 508 deletion (F508del) CFTR variant as well as the over 2000 CF-associated variants remains controversial. To address this concern, we examined the impact of US Food and Drug Administration-approved HDACi on the trafficking and function of a panel of CFTR variants. Our data reveal that panobinostat (LBH-589) and romidepsin (FK-228) provide functional correction of Class II and III CFTR variants, restoring cell surface chloride channel activity in primary human bronchial epithelial cells. We further demonstrate a synergistic effect of these HDACi with Vx809, which can significantly restore channel activity for multiple CFTR variants. These data suggest that HDACi can serve to level the cellular playing field for correcting CF-causing mutations, a leveling effect that might also extend to other protein-misfolding diseases.
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Affiliation(s)
- Frédéric Anglès
- Department of Molecular Medicine, Scripps Research, North Torrey Pines Rd, La Jolla, CA, USA
| | - Darren M Hutt
- Department of Molecular Medicine, Scripps Research, North Torrey Pines Rd, La Jolla, CA, USA
| | - William E Balch
- Department of Molecular Medicine, Scripps Research, North Torrey Pines Rd, La Jolla, CA, USA.,Skaggs Institute of Chemical Biology, North Torrey Pines Rd, La Jolla, CA, USA
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7
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Regulation of CFTR Biogenesis by the Proteostatic Network and Pharmacological Modulators. Int J Mol Sci 2020; 21:ijms21020452. [PMID: 31936842 PMCID: PMC7013518 DOI: 10.3390/ijms21020452] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2019] [Revised: 01/06/2020] [Accepted: 01/08/2020] [Indexed: 12/14/2022] Open
Abstract
Cystic fibrosis (CF) is the most common lethal inherited disease among Caucasians in North America and a significant portion of Europe. The disease arises from one of many mutations in the gene encoding the cystic fibrosis transmembrane conductance regulator, or CFTR. The most common disease-associated allele, F508del, along with several other mutations affect the folding, transport, and stability of CFTR as it transits from the endoplasmic reticulum (ER) to the plasma membrane, where it functions primarily as a chloride channel. Early data demonstrated that F508del CFTR is selected for ER associated degradation (ERAD), a pathway in which misfolded proteins are recognized by ER-associated molecular chaperones, ubiquitinated, and delivered to the proteasome for degradation. Later studies showed that F508del CFTR that is rescued from ERAD and folds can alternatively be selected for enhanced endocytosis and lysosomal degradation. A number of other disease-causing mutations in CFTR also undergo these events. Fortunately, pharmacological modulators of CFTR biogenesis can repair CFTR, permitting its folding, escape from ERAD, and function at the cell surface. In this article, we review the many cellular checkpoints that monitor CFTR biogenesis, discuss the emergence of effective treatments for CF, and highlight future areas of research on the proteostatic control of CFTR.
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8
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Hanrahan JW, Sato Y, Carlile GW, Jansen G, Young JC, Thomas DY. Cystic Fibrosis: Proteostatic correctors of CFTR trafficking and alternative therapeutic targets. Expert Opin Ther Targets 2019; 23:711-724. [PMID: 31169041 DOI: 10.1080/14728222.2019.1628948] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Introduction: Cystic fibrosis (CF) is the most frequent lethal orphan disease and is caused by mutations in the CFTR gene. The most frequent mutation F508del-CFTR affects multiple organs; infections and subsequent infections and complications in the lung lead to death. Areas covered: This review focuses on new targets and mechanisms that are attracting interest for the development of CF therapies. The F508del-CFTR protein is retained in the endoplasmic reticulum (ER) but has some function if it can traffic to the plasma membrane. Cell-based assays have been used to screen chemical libraries for small molecule correctors that restore its trafficking. Pharmacological chaperones are correctors that bind directly to the F508del-CFTR mutant and promote its folding and trafficking. Other correctors fall into a heterogeneous class of proteostasis modulators that act indirectly by altering cellular homeostasis. Expert opinion: Pharmacological chaperones have so far been the most successful correctors of F508del-CFTR trafficking, but their level of correction means that more than one corrector is required. Proteostasis modulators have low levels of correction but hold promise because some can correct several different CFTR mutations. Identification of their cellular targets and the potential for development may lead to new therapies for CF.
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Affiliation(s)
- John W Hanrahan
- a Department of Physiology , McGill University , Montréal , QC , Canada.,c Research Institute of the McGill University Health Centre , McGill University , Montréal , QC , Canada
| | - Yukiko Sato
- a Department of Physiology , McGill University , Montréal , QC , Canada.,b Cystic Fibrosis Translational Research centre , McGill University , Montréal , QC , Canada
| | - Graeme W Carlile
- b Cystic Fibrosis Translational Research centre , McGill University , Montréal , QC , Canada.,d Department of Biochemistry , McGill University , Montréal , QC , Canada
| | - Gregor Jansen
- d Department of Biochemistry , McGill University , Montréal , QC , Canada
| | - Jason C Young
- b Cystic Fibrosis Translational Research centre , McGill University , Montréal , QC , Canada.,d Department of Biochemistry , McGill University , Montréal , QC , Canada
| | - David Y Thomas
- b Cystic Fibrosis Translational Research centre , McGill University , Montréal , QC , Canada.,d Department of Biochemistry , McGill University , Montréal , QC , Canada.,e Department of Human Genetics , McGill University , Montréal , QC , Canada
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9
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Bentley SJ, Jamabo M, Boshoff A. The Hsp70/J-protein machinery of the African trypanosome, Trypanosoma brucei. Cell Stress Chaperones 2019; 24:125-148. [PMID: 30506377 PMCID: PMC6363631 DOI: 10.1007/s12192-018-0950-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Revised: 11/06/2018] [Accepted: 11/12/2018] [Indexed: 12/28/2022] Open
Abstract
The etiological agent of the neglected tropical disease African trypanosomiasis, Trypanosoma brucei, possesses an expanded and diverse repertoire of heat shock proteins, which have been implicated in cytoprotection, differentiation, as well as progression and transmission of the disease. Hsp70 plays a crucial role in proteostasis, and inhibition of its interactions with co-chaperones is emerging as a potential therapeutic target for numerous diseases. In light of genome annotations and the release of the genome sequence of the human infective subspecies, an updated and current in silico overview of the Hsp70/J-protein machinery in both T. brucei brucei and T. brucei gambiense was conducted. Functional, structural, and evolutionary analyses of the T. brucei Hsp70 and J-protein families were performed. The Hsp70 and J-proteins from humans and selected kinetoplastid parasites were used to assist in identifying proteins from T. brucei, as well as the prediction of potential Hsp70-J-protein partnerships. The Hsp70 and J-proteins were mined from numerous genome-wide proteomics studies, which included different lifecycle stages and subcellular localisations. In this study, 12 putative Hsp70 proteins and 67 putative J-proteins were identified to be encoded on the genomes of both T. brucei subspecies. Interestingly there are 6 type III J-proteins that possess tetratricopeptide repeat-containing (TPR) motifs. Overall, it is envisioned that the results of this study will provide a future context for studying the biology of the African trypanosome and evaluating Hsp70 and J-protein interactions as potential drug targets.
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Affiliation(s)
| | - Miebaka Jamabo
- Biotechnology Innovation Centre, Rhodes University, Grahamstown, South Africa
| | - Aileen Boshoff
- Biotechnology Innovation Centre, Rhodes University, Grahamstown, South Africa.
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Regulation of Human Hsc70 ATPase and Chaperone Activities by Apg2: Role of the Acidic Subdomain. J Mol Biol 2018; 431:444-461. [PMID: 30521813 DOI: 10.1016/j.jmb.2018.11.026] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Revised: 10/30/2018] [Accepted: 11/26/2018] [Indexed: 12/28/2022]
Abstract
Protein aggregate reactivation in metazoans is accomplished by the combined activity of Hsp70, Hsp40 and Hsp110 chaperones. Hsp110s support the refolding of aggregated polypeptides acting as specialized nucleotide exchange factors of Hsp70. We have studied how Apg2, one of the three human Hsp110s, regulates the activity of Hsc70 (HspA8), the constitutive Hsp70 in our cells. Apg2 shows a biphasic behavior: at low concentration, it stimulates the ATPase cycle of Hsc70, binding of the chaperone to protein aggregates and the refolding activity of the system, while it inhibits these three processes at high concentration. When the acidic subdomain of Apg2, a characteristic sequence present in the substrate binding domain of all Hsp110s, is deleted, the detrimental effects occur at lower concentration and are more pronounced, which concurs with an increase in the affinity of the Apg2 mutant for Hsc70. Our data support a mechanism in which Apg2 arrests the chaperone cycle through an interaction with Hsc70(ATP) that might lead to premature ATP dissociation before hydrolysis. In this line, the acidic subdomain might serve as a conformational switch to support dissociation of the Hsc70:Apg2 complex.
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11
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Hutt DM, Loguercio S, Campos AR, Balch WE. A Proteomic Variant Approach (ProVarA) for Personalized Medicine of Inherited and Somatic Disease. J Mol Biol 2018; 430:2951-2973. [PMID: 29924966 PMCID: PMC6097907 DOI: 10.1016/j.jmb.2018.06.017] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Revised: 06/07/2018] [Accepted: 06/08/2018] [Indexed: 12/21/2022]
Abstract
The advent of precision medicine for genetic diseases has been hampered by the large number of variants that cause familial and somatic disease, a complexity that is further confounded by the impact of genetic modifiers. To begin to understand differences in onset, progression and therapeutic response that exist among disease-causing variants, we present the proteomic variant approach (ProVarA), a proteomic method that integrates mass spectrometry with genomic tools to dissect the etiology of disease. To illustrate its value, we examined the impact of variation in cystic fibrosis (CF), where 2025 disease-associated mutations in the CF transmembrane conductance regulator (CFTR) gene have been annotated and where individual genotypes exhibit phenotypic heterogeneity and response to therapeutic intervention. A comparative analysis of variant-specific proteomics allows us to identify a number of protein interactions contributing to the basic defects associated with F508del- and G551D-CFTR, two of the most common disease-associated variants in the patient population. We demonstrate that a number of these causal interactions are significantly altered in response to treatment with Vx809 and Vx770, small-molecule therapeutics that respectively target the F508del and G551D variants. ProVarA represents the first comparative proteomic analysis among multiple disease-causing mutations, thereby providing a methodological approach that provides a significant advancement to existing proteomic efforts in understanding the impact of variation in CF disease. We posit that the implementation of ProVarA for any familial or somatic mutation will provide a substantial increase in the knowledge base needed to implement a precision medicine-based approach for clinical management of disease.
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Affiliation(s)
- Darren M Hutt
- The Scripps Research Institute, Department of Molecular Medicine, 10550 North Torrey Pines Rd, La Jolla CA USA 92037
| | - Salvatore Loguercio
- The Scripps Research Institute, Department of Molecular Medicine, 10550 North Torrey Pines Rd, La Jolla CA USA 92037
| | - Alexandre Rosa Campos
- Sanford Burnham Prebys Medical Discovery Institute Proteomic Core 10901 North Torrey Pines Road, La Jolla CA USA 92037
| | - William E Balch
- The Scripps Research Institute, Department of Molecular Medicine, 10550 North Torrey Pines Rd, La Jolla CA USA 92037
- Integrative Structural and Computational Biology, 10550 North Torrey Pines Rd, La Jolla CA USA 92037
- The Skaggs Institute for Chemical Biology, 10550 North Torrey Pines Rd, La Jolla CA USA 92037
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12
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Hutt DM, Loguercio S, Roth DM, Su AI, Balch WE. Correcting the F508del-CFTR variant by modulating eukaryotic translation initiation factor 3-mediated translation initiation. J Biol Chem 2018; 293:13477-13495. [PMID: 30006345 DOI: 10.1074/jbc.ra118.003192] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Revised: 07/05/2018] [Indexed: 12/31/2022] Open
Abstract
Inherited and somatic rare diseases result from >200,000 genetic variants leading to loss- or gain-of-toxic function, often caused by protein misfolding. Many of these misfolded variants fail to properly interact with other proteins. Understanding the link between factors mediating the transcription, translation, and protein folding of these disease-associated variants remains a major challenge in cell biology. Herein, we utilized the cystic fibrosis transmembrane conductance regulator (CFTR) protein as a model and performed a proteomics-based high-throughput screen (HTS) to identify pathways and components affecting the folding and function of the most common cystic fibrosis-associated mutation, the F508del variant of CFTR. Using a shortest-path algorithm we developed, we mapped HTS hits to the CFTR interactome to provide functional context to the targets and identified the eukaryotic translation initiation factor 3a (eIF3a) as a central hub for the biogenesis of CFTR. Of note, siRNA-mediated silencing of eIF3a reduced the polysome-to-monosome ratio in F508del-expressing cells, which, in turn, decreased the translation of CFTR variants, leading to increased CFTR stability, trafficking, and function at the cell surface. This finding suggested that eIF3a is involved in mediating the impact of genetic variations in CFTR on the folding of this protein. We posit that the number of ribosomes on a CFTR mRNA transcript is inversely correlated with the stability of the translated polypeptide. Polysome-based translation challenges the capacity of the proteostasis environment to balance message fidelity with protein folding, leading to disease. We suggest that this deficit can be corrected through control of translation initiation.
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Affiliation(s)
| | | | | | - Andrew I Su
- Integrative Structural and Computational Biology and
| | - William E Balch
- From the Departments of Molecular Medicine and .,the Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, California 92037
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13
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Huang X, Dong H, Ting Z. Cloning, expression of a truncated HSP110 protein that augments the activities of tumor antigen-specific cytotoxic and apoptosis via tHSP110-peptide complex vaccines. INTERNATIONAL JOURNAL OF CLINICAL AND EXPERIMENTAL PATHOLOGY 2017; 10:10304-10314. [PMID: 31966365 PMCID: PMC6965763] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Accepted: 08/09/2017] [Indexed: 06/10/2023]
Abstract
The present study used a genetic engineering method to express a truncated heat shock protein 110 (tHSP110) isoform in Escherichia coli and verified its ability to bind to and present macromolecular antigens. Polymerase chain reaction (PCR) was used to obtain the truncated HSP110 gene, which was expressed in E. coli. The tHSP110 protein was non-covalently coupled to the intracellular domain (ICD) of human epidermal growth factor receptor 2 (HER2/Neu) in vitro to construct the antigen peptide complex tHSP110-ICD, which was identified by a co-immunoprecipitation assay. BALB/c mice were immunized 14-day interval for three times with the HSP110, tHSP110, HSP110-ICD, tHSP110-ICD, HSP110-P851-859 (a complex formed by full-length HSP110 with a cytotoxic T lymphocyte (CTL) epitope peptide of the Her2/neu ICD) and tHSP110-P851-859 complexes. Fourteen days after the last immunization, D2F2 cells were inoculated into BALB/c mice. The in vivo tumor volume of each group was measured every three days after cell inoculation to evaluate the immunization efficacy of the vaccine in each group. The level of the IFN-γ secreted by activated lymphocytes, the specific CTLs activity was detected. Immunohistochemical staining of bcl-2 and bax were measured on the tumor tissues of each group. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) showed that the expressed tHSP110 protein was 66 kDa in size. The non-covalent coupling of tHSP110 with ICD and peptide were confirmed by a co-immunoprecipitation assay. The in vivo tumor experiment results indicated no differences in the tumor volumes of the tHSP110-ICD and HSP110-ICD groups. In contrast, the tumor volume of the tHSP110-ICD group was significantly different compared with the tumor volume of the tHSP110-P851-859 group. After the mice immunized with tHSP110-ICD, tHSP110-P851-859 complexes, the complexes have potential immunogenicity, and can induce specific CTLs activity and apoptosis in BALB/c mice. As a tumor vaccine to inhibit in vivo tumor growth, the tHSP110 has the same ability to bind macromolecular antigens and activate tumor immune responses as full-length HSP110.
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Affiliation(s)
- Xu Huang
- Jiaxing University Medical CollegeJiaxing, Zhejiang, China
| | - Han Dong
- Jiaxing University Medical CollegeJiaxing, Zhejiang, China
| | - Zhang Ting
- College of Medical Technology, Zhejiang Chinese Medical UniversityHangzhou, China
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Mota R, Rodríguez JE, Bonetto A, O’Connell TM, Asher SA, Parry TL, Lockyer P, McCudden CR, Couch ME, Willis MS. Post-translationally modified muscle-specific ubiquitin ligases as circulating biomarkers in experimental cancer cachexia. Am J Cancer Res 2017; 7:1948-1958. [PMID: 28979816 PMCID: PMC5622228] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Accepted: 08/24/2017] [Indexed: 06/07/2023] Open
Abstract
Cancer cachexia is a severe wasting syndrome characterized by the progressive loss of lean body mass and systemic inflammation. Up to 80% of cancer patients experience cachexia, with 20-30% of cancer-related deaths directly linked to cachexia. Despite efforts to identify early cachexia and cancer relapse, clinically useful markers are lacking. Recently, we identified the role of muscle-specific ubiquitin ligases Atrogin-1 (MAFbx, FBXO32) and Muscle Ring Finger-1 in the pathogenesis of cardiac atrophy and hypertrophy. We hypothesized that during cachexia, the Atrogin-1 and MuRF1 ubiquitin ligases are released from muscle and migrate to the circulation where they could be detected and serve as a cachexia biomarker. To test this, we induced cachexia in mice using the C26 adenocarcinoma cells or vehicle (control). Body weight, tumor volume, and food consumption were measured from inoculation until ~day 14 to document cachexia. Western blot analysis of serum identified the presence of Atrogin-1 and MuRF1 with unique post-translational modifications consistent with mono- and poly- ubiquitination of Atrogin-1 and MuRF1 found only in cachectic serum. These findings suggest that both increased Atrogin-1 and the presence of unique post-translational modifications may serve as a surrogate marker specific for cachexia.
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Affiliation(s)
- Roberto Mota
- McAllister Heart Institute, University of North CarolinaChapel Hill, NC, USA
- Division of Vascular Surgery, Department of Surgery, University of North CarolinaChapel Hill, NC, USA (Current)
| | - Jessica E Rodríguez
- Department of Pathology & Laboratory Medicine, University of North CarolinaChapel Hill, NC, USA
- Montefiore Medical Center, The University Hospital for Albert Einstein College of MedicineBronx, NY, USA (Current)
| | - Andrea Bonetto
- Department of Surgery, Indiana University School of MedicineIndianapolis, IN, USA
- Department of Otolaryngology, Head and Neck Surgery, Indiana University School of MedicineIndianapolis, IN, USA
- Simon Cancer Center, Indiana University School of Medicine, Indiana University-Purdue University at Indianapolis, Center for Cachexia Research, Innovation and Therapy, Indiana University School of MedicineIndianapolis, IN, USA
- Indiana Center for Musculoskeletal Health, Indiana UniversityIndianapolis, IN, USA
| | - Thomas M O’Connell
- Department of Otolaryngology, Head and Neck Surgery, Indiana University School of MedicineIndianapolis, IN, USA
- Simon Cancer Center, Indiana University School of Medicine, Indiana University-Purdue University at Indianapolis, Center for Cachexia Research, Innovation and Therapy, Indiana University School of MedicineIndianapolis, IN, USA
- Indiana Center for Musculoskeletal Health, Indiana UniversityIndianapolis, IN, USA
- Department of Otolaryngology-Head and Neck Surgery, University of North Carolina, School of MedicineChapel Hill, North Carolina, USA
| | - Scott A Asher
- Department of Otolaryngology-Head and Neck Surgery, University of North Carolina, School of MedicineChapel Hill, North Carolina, USA
- Division of Surgery, Department of Clinical Sciences, The Florida State University College of MedicineTallahassee, FL, USA (Current)
| | - Traci L Parry
- McAllister Heart Institute, University of North CarolinaChapel Hill, NC, USA
- Department of Pathology & Laboratory Medicine, University of North CarolinaChapel Hill, NC, USA
| | - Pamela Lockyer
- McAllister Heart Institute, University of North CarolinaChapel Hill, NC, USA
- Department of Pathology & Laboratory Medicine, University of North CarolinaChapel Hill, NC, USA
| | - Christopher R McCudden
- Department of Pathology & Laboratory Medicine, University of North CarolinaChapel Hill, NC, USA
- Department of Pathology & Laboratory Medicine, University of OttawaOttawa ON, Canada (Current)
| | - Marion E Couch
- Department of Otolaryngology, Head and Neck Surgery, Indiana University School of MedicineIndianapolis, IN, USA
- Simon Cancer Center, Indiana University School of Medicine, Indiana University-Purdue University at Indianapolis, Center for Cachexia Research, Innovation and Therapy, Indiana University School of MedicineIndianapolis, IN, USA
- Department of Otolaryngology-Head and Neck Surgery, University of North Carolina, School of MedicineChapel Hill, North Carolina, USA
| | - Monte S Willis
- McAllister Heart Institute, University of North CarolinaChapel Hill, NC, USA
- Department of Pathology & Laboratory Medicine, University of North CarolinaChapel Hill, NC, USA
- Department of Pharmacology, University of North CarolinaChapel Hill, NC, USA
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15
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Garcia VM, Nillegoda NB, Bukau B, Morano KA. Substrate binding by the yeast Hsp110 nucleotide exchange factor and molecular chaperone Sse1 is not obligate for its biological activities. Mol Biol Cell 2017; 28:2066-2075. [PMID: 28539411 PMCID: PMC5509420 DOI: 10.1091/mbc.e17-01-0070] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Revised: 05/15/2017] [Accepted: 05/17/2017] [Indexed: 02/05/2023] Open
Abstract
The highly conserved heat shock protein 70 (Hsp70) is a ubiquitous molecular chaperone essential for maintaining cellular protein homeostasis. The related protein Hsp110 (Sse1/Sse2 in Saccharomyces cerevisiae) functions as a nucleotide exchange factor (NEF) to regulate the protein folding activity of Hsp70. Hsp110/Sse1 also can prevent protein aggregation in vitro via its substrate-binding domain (SBD), but the cellular roles of this "holdase" activity are poorly defined. We generated and characterized an Sse1 mutant that separates, for the first time, its nucleotide exchange and substrate-binding functions. Sse1sbd retains nucleotide-binding and nucleotide exchange activities while exhibiting severe deficiencies in chaperone holdase activity for unfolded polypeptides. In contrast, we observed no effect of the SBD mutation in reconstituted disaggregation or refolding reactions in vitro. In vivo, Sse1sbd successfully heterodimerized with the yeast cytosolic Hsp70s Ssa and Ssb and promoted normal growth, with the exception of sensitivity to prolonged heat but not other proteotoxic stress. Moreover, Sse1sbd was fully competent to support Hsp90-dependent signaling through heterologously expressed glucocorticoid receptor and degradation of a permanently misfolded protein, two previously defined roles for Sse1. We conclude that despite conservation among eukaryotic homologues, chaperone holdase activity is not an obligate function in the Hsp110 family.
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Affiliation(s)
- Veronica M Garcia
- Department of Microbiology and Molecular Genetics, University of Texas McGovern Medical School at Houston, Houston, TX 77030.,MD Anderson UT Health Graduate School of Biomedical Sciences, Houston, TX 77030
| | - Nadinath B Nillegoda
- Center for Molecular Biology of Heidelberg University and German Cancer Research Center, D-69120 Heidelberg, Germany
| | - Bernd Bukau
- Center for Molecular Biology of Heidelberg University and German Cancer Research Center, D-69120 Heidelberg, Germany
| | - Kevin A Morano
- Department of Microbiology and Molecular Genetics, University of Texas McGovern Medical School at Houston, Houston, TX 77030
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16
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Qin L, Guo J, Zheng Q, Zhang H. BAG2 structure, function and involvement in disease. Cell Mol Biol Lett 2016; 21:18. [PMID: 28536620 PMCID: PMC5415834 DOI: 10.1186/s11658-016-0020-2] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2016] [Accepted: 09/10/2016] [Indexed: 12/30/2022] Open
Abstract
Bcl2-associated athanogene 2 (BAG2) shares a similar molecular structure and function with other BAG family members. Functioning as a co-chaperone, it interacts with the ATPase domain of the heat shock protein 70 (dHsp70) through its BAG domain. It also interacts with many other molecules and regulates various cellular functions. An increasing number of studies have indicated that BAG2 is involved in the pathogenesis of various diseases, including cancers and neurodegenerative diseases. This paper is a comprehensive review of the structure, functions, and protein interactions of BAG2. We also discuss its roles in diseases, including cancer, Alzheimer's disease, Parkinson's disease and spinocerebellar ataxia type-3. Further research on BAG2 could lead to an understanding of the pathogenesis of these disorders or even to novel therapeutic approaches.
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Affiliation(s)
- Lixia Qin
- Department of Neurology, The Second Xiangya Hospital, Central South University, Changsha, China.,Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
| | - Jifeng Guo
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
| | - Qian Zheng
- Department of Neurology, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Hainan Zhang
- Department of Neurology, The Second Xiangya Hospital, Central South University, Changsha, China
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17
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Wang FY, Zhang YQ, Wang XM, Wang C, Wang XF, Wu JD, Wu F, Zhang WJ, Zhang L. A small hairpin RNA targeting myeloid cell leukemia-1 enhances apoptosis in host macrophages infected with Mycobacterium tuberculosis. J Microbiol 2016; 54:330-7. [DOI: 10.1007/s12275-016-5627-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Revised: 02/19/2016] [Accepted: 02/22/2016] [Indexed: 01/24/2023]
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18
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Zuo D, Subjeck J, Wang XY. Unfolding the Role of Large Heat Shock Proteins: New Insights and Therapeutic Implications. Front Immunol 2016; 7:75. [PMID: 26973652 PMCID: PMC4771732 DOI: 10.3389/fimmu.2016.00075] [Citation(s) in RCA: 67] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2015] [Accepted: 02/15/2016] [Indexed: 11/13/2022] Open
Abstract
Heat shock proteins (HSPs) of eukaryotes are evolutionarily conserved molecules present in all the major intracellular organelles. They mainly function as molecular chaperones and participate in maintenance of protein homeostasis in physiological state and under stressful conditions. Despite their relative abundance, the large HSPs, i.e., Hsp110 and glucose-regulated protein 170 (Grp170), have received less attention compared to other conventional HSPs. These proteins are distantly related to the Hsp70 and belong to Hsp70 superfamily. Increased sizes of Hsp110 and Grp170, due to the presence of a loop structure, result in their exceptional capability in binding to polypeptide substrates or non-protein ligands, such as pathogen-associated molecules. These interactions that occur in the extracellular environment during tissue injury or microbial infection may lead to amplification of an immune response engaging both innate and adaptive immune components. Here, we review the current advances in understanding these large HSPs as molecular chaperones in proteostasis control and immune modulation as well as their therapeutic implications in treatment of cancer and neurodegeneration. Given their unique immunoregulatory activities, we also discuss the emerging evidence of their potential involvement in inflammatory and immune-related diseases.
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Affiliation(s)
- Daming Zuo
- Department of Immunology, Southern Medical University, Guangzhou, China; State Key Laboratory of Organ Failure Research, Department of Infectious Diseases, Nanfang Hospital, Southern Medical University, Guangzhou, China; Guangdong Provincial Key Laboratory of Viral Hepatitis Research, Department of Infectious Diseases, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - John Subjeck
- Department of Cellular Stress Biology, Roswell Park Cancer Institute , Buffalo, NY , USA
| | - Xiang-Yang Wang
- Department of Human and Molecular Genetics, Virginia Commonwealth University, Richmond, VA, USA; VCU Massey Cancer Center, Virginia Commonwealth University, Richmond, VA, USA; VCU Institute of Molecular Medicine, Virginia Commonwealth University, Richmond, VA, USA
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19
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Foo B, Williamson B, Young JC, Lukacs G, Shrier A. hERG quality control and the long QT syndrome. J Physiol 2016; 594:2469-81. [PMID: 26718903 DOI: 10.1113/jp270531] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2015] [Accepted: 12/07/2015] [Indexed: 11/08/2022] Open
Abstract
Long-QT syndrome type-2 (LQT2) is characterized by reduced functional expression of the human ether-à-go-go related (hERG) gene product, resulting in impaired cardiac repolarization and predisposition to fatal arrhythmia. Previous studies have implicated abnormal trafficking of misfolded hERG as the primary mechanism of LQT2, with misfolding being caused by mutations in the hERG gene (inherited) or drug treatment (acquired). More generally, environmental and metabolic stresses present a constant challenge to the folding of proteins, including hERG, and must be countered by robust protein quality control (QC) systems. Disposal of partially unfolded yet functional plasma membrane (PM) proteins by protein QC contributes to the loss-of-function phenotype in various conformational diseases including cystic fibrosis (CF) and long-QT syndrome type-2 (LQT2). The prevalent view has been that the loss of PM expression of hERG is attributed to biosynthetic block by endoplasmic reticulum (ER) QC pathways. However, there is a growing appreciation for protein QC pathways acting at post-ER cellular compartments, which may contribute to conformational disease pathogenesis. This article will provide a background on the structure and cellular trafficking of hERG as well as inherited and acquired LQT2. We will review previous work on hERG ER QC and introduce the more novel view that there is a significant peripheral QC at the PM and peripheral cellular compartments. Particular attention is drawn to the unique role of the peripheral QC system in acquired LQT2. Understanding the QC process and players may provide targets for therapeutic intervention in dealing with LQT2.
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Affiliation(s)
- Brian Foo
- Department of Physiology, McGill University, Montréal, Québec, Canada, H3G 1Y6
| | - Brittany Williamson
- Department of Biochemistry, McGill University, Montréal, Québec, Canada, H3G 1Y6
| | - Jason C Young
- Department of Biochemistry, McGill University, Montréal, Québec, Canada, H3G 1Y6
| | - Gergely Lukacs
- Department of Physiology, McGill University, Montréal, Québec, Canada, H3G 1Y6
| | - Alvin Shrier
- Department of Physiology, McGill University, Montréal, Québec, Canada, H3G 1Y6
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20
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Narayan M, Seeley KW, Jinwal UK. Identification and quantitative analysis of cellular proteins affected by treatment with withaferin a using a SILAC-based proteomics approach. JOURNAL OF ETHNOPHARMACOLOGY 2015; 175:86-92. [PMID: 26392330 DOI: 10.1016/j.jep.2015.09.024] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Revised: 08/24/2015] [Accepted: 09/17/2015] [Indexed: 06/05/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Withaferin A (WA) is a major bioactive compound isolated from the medicinal plant Withania somnifera Dunal, also known as "Ashwagandha". A number of published reports suggest various uses for WA including its function as an anti-inflammatory and anti-angiogenic drug molecule. The effects of WA at the molecular level in a cellular environment are not well understood. Knowledge of the molecular mechanism of action of WA could enhance its therapeutic value and may reveal novel pathways it may modulate. MATERIALS AND METHODS In order to identify and characterize proteins affected by treatment with WA, we used SILAC- based proteomics analysis on a mouse microglial cell line (N9), which replicates phenotypic characteristics of primary microglial cells. RESULTS Using stable isotope labeling of amino acids in cell culture (SILAC) and mass spectrometry (MS), a total of 2300 unique protein groups were identified from three biological replicates, with significant expression changes in 32 non-redundant proteins. The top biological functions associated with these differentially expressed proteins include cell death and survival, free radical scavenging, and carbohydrate metabolism. Specifically, several heat shock proteins (Hsps) were found to be upregulated, which suggests that the chaperonic machinery might be regulated by WA. Furthermore, our study revealed several novel protein molecules that were not previously reported to be affected by WA. Among them, annexin A1, a key anti-inflammatory molecule in microglial cells was found to be downregulated. Hsc70, Hsp90α and Hsp105 were found to be upregulated. We also found sequestosome1/p62 (p62) to be upregulated. We performed Ingenuity Pathway Analysis (IPA) and found a number of pathways that were affected by WA treatment. CONCLUSIONS SILAC-based proteomics analysis of a microglial cell model revealed several novel proteins whose expression is regulated by WA and probable pathways regulated by WA.
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Affiliation(s)
- Malathi Narayan
- Department of Pharmaceutical Sciences, College of Pharmacy, Byrd Alzheimer's Institute, University of South Florida-Health, 4001 E. Fletcher Ave, MDC36, Tampa, FL 33613, United States
| | - Kent W Seeley
- Florida Center of Excellence for Drug Discovery & Innovation at the University of South Florida, 3720 Spectrum Blvd., Suite 303, IDR Building, Tampa, FL 33612, United States
| | - Umesh K Jinwal
- Department of Pharmaceutical Sciences, College of Pharmacy, Byrd Alzheimer's Institute, University of South Florida-Health, 4001 E. Fletcher Ave, MDC36, Tampa, FL 33613, United States.
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21
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Amaral MD, Balch WE. Hallmarks of therapeutic management of the cystic fibrosis functional landscape. J Cyst Fibros 2015; 14:687-99. [PMID: 26526359 PMCID: PMC4644672 DOI: 10.1016/j.jcf.2015.09.006] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Revised: 09/16/2015] [Accepted: 09/16/2015] [Indexed: 01/29/2023]
Abstract
The cystic fibrosis (CF) transmembrane conductance regulator (CFTR) protein does not operate in isolation, rather in a dynamic network of interacting components that impact its synthesis, folding, stability, intracellular location and function, referred to herein as the 'CFTR Functional Landscape (CFFL)'. For the prominent F508del mutation, many of these interactors are deeply connected to a protein fold management system, the proteostasis network (PN). However, CF encompasses an additional 2000 CFTR variants distributed along its entire coding sequence (referred to as CFTR2), and each variant contributes a differential liability to PN management of CFTR and to a protein 'social network' (SN) that directs the probability of the (patho)physiologic events that impact ion transport in each cell, tissue and patient in health and disease. Recognition of the importance of the PN and SN in driving the unique patient CFFL leading to disease highlights the importance of precision medicine in therapeutic management of disease progression. We take the view herein that it is not CFTR, rather the PN/SN, and their impact on the CFFL, that are the key physiologic forces driving onset and clinical progression of CF. We posit that a deep understanding of each patients PN/SN gained by merging genomic, proteomic (mass spectrometry (MS)), and high-content microscopy (HCM) technologies in the context of novel network learning algorithms will lead to a paradigm shift in CF clinical management. This should allow for generation of new classes of patient specific PN/SN directed therapeutics for personalized management of the CFFL in the clinic.
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Affiliation(s)
- Margarida D Amaral
- University of Lisboa, Faculty of Sciences, BioISI - Biosystems & Integrative Sciences Institute, Lisboa, Portugal.
| | - William E Balch
- Department of Chemical Physiology, Department of Cell and Molecular Biology, The Skaggs Institute of Chemical Biology, The Scripps Research Institute, La Jolla, CA, USA.
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22
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Nillegoda NB, Bukau B. Metazoan Hsp70-based protein disaggregases: emergence and mechanisms. Front Mol Biosci 2015; 2:57. [PMID: 26501065 PMCID: PMC4598581 DOI: 10.3389/fmolb.2015.00057] [Citation(s) in RCA: 87] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Accepted: 09/22/2015] [Indexed: 11/13/2022] Open
Abstract
Proteotoxic stresses and aging cause breakdown of cellular protein homeostasis, allowing misfolded proteins to form aggregates, which dedicated molecular machines have evolved to solubilize. In bacteria, fungi, protozoa and plants protein disaggregation involves an Hsp70•J-protein chaperone system, which loads and activates a powerful AAA+ ATPase (Hsp100) disaggregase onto protein aggregate substrates. Metazoans lack cytosolic and nuclear Hsp100 disaggregases but still eliminate protein aggregates. This longstanding puzzle of protein quality control is now resolved. Robust protein disaggregation activity recently shown for the metazoan Hsp70-based disaggregases relies instead on a crucial cooperation between two J-protein classes and interaction with the Hsp110 co-chaperone. An expanding multiplicity of Hsp70 and J-protein family members in metazoan cells facilitates different configurations of this Hsp70-based disaggregase allowing unprecedented versatility and specificity in protein disaggregation. Here we review the architecture, operation, and adaptability of the emerging metazoan disaggregation system and discuss how this evolved.
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Affiliation(s)
- Nadinath B Nillegoda
- Center for Molecular Biology (ZMBH) of the University of Heidelberg and German Cancer Research Center (DKFZ), DKFZ-ZMBH Alliance Heidelberg, Germany
| | - Bernd Bukau
- Center for Molecular Biology (ZMBH) of the University of Heidelberg and German Cancer Research Center (DKFZ), DKFZ-ZMBH Alliance Heidelberg, Germany
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23
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Nillegoda NB, Bukau B. Metazoan Hsp70-based protein disaggregases: emergence and mechanisms. Front Mol Biosci 2015; 2:57. [PMID: 26501065 DOI: 10.3389/fmolb.2015.00057/bibtex] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Accepted: 09/22/2015] [Indexed: 05/25/2023] Open
Abstract
Proteotoxic stresses and aging cause breakdown of cellular protein homeostasis, allowing misfolded proteins to form aggregates, which dedicated molecular machines have evolved to solubilize. In bacteria, fungi, protozoa and plants protein disaggregation involves an Hsp70•J-protein chaperone system, which loads and activates a powerful AAA+ ATPase (Hsp100) disaggregase onto protein aggregate substrates. Metazoans lack cytosolic and nuclear Hsp100 disaggregases but still eliminate protein aggregates. This longstanding puzzle of protein quality control is now resolved. Robust protein disaggregation activity recently shown for the metazoan Hsp70-based disaggregases relies instead on a crucial cooperation between two J-protein classes and interaction with the Hsp110 co-chaperone. An expanding multiplicity of Hsp70 and J-protein family members in metazoan cells facilitates different configurations of this Hsp70-based disaggregase allowing unprecedented versatility and specificity in protein disaggregation. Here we review the architecture, operation, and adaptability of the emerging metazoan disaggregation system and discuss how this evolved.
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Affiliation(s)
- Nadinath B Nillegoda
- Center for Molecular Biology (ZMBH) of the University of Heidelberg and German Cancer Research Center (DKFZ), DKFZ-ZMBH Alliance Heidelberg, Germany
| | - Bernd Bukau
- Center for Molecular Biology (ZMBH) of the University of Heidelberg and German Cancer Research Center (DKFZ), DKFZ-ZMBH Alliance Heidelberg, Germany
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24
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A Non-enveloped Virus Hijacks Host Disaggregation Machinery to Translocate across the Endoplasmic Reticulum Membrane. PLoS Pathog 2015; 11:e1005086. [PMID: 26244546 PMCID: PMC4526233 DOI: 10.1371/journal.ppat.1005086] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2015] [Accepted: 07/15/2015] [Indexed: 02/02/2023] Open
Abstract
Mammalian cytosolic Hsp110 family, in concert with the Hsc70:J-protein complex, functions as a disaggregation machinery to rectify protein misfolding problems. Here we uncover a novel role of this machinery in driving membrane translocation during viral entry. The non-enveloped virus SV40 penetrates the endoplasmic reticulum (ER) membrane to reach the cytosol, a critical infection step. Combining biochemical, cell-based, and imaging approaches, we find that the Hsp110 family member Hsp105 associates with the ER membrane J-protein B14. Here Hsp105 cooperates with Hsc70 and extracts the membrane-penetrating SV40 into the cytosol, potentially by disassembling the membrane-embedded virus. Hence the energy provided by the Hsc70-dependent Hsp105 disaggregation machinery can be harnessed to catalyze a membrane translocation event. How non-enveloped viruses penetrate a host membrane to enter cells and cause disease remains an enigmatic step. To infect cells, the non-enveloped SV40 must transport across the ER membrane to reach the cytosol. In this study, we report that a cellular Hsp105-powered disaggregation machinery pulls SV40 into the cytosol, likely by uncoating the ER membrane-penetrating virus. Because this disaggregation machinery is thought to clarify cellular aggregated proteins, we propose that the force generated by this machinery can also be hijacked by a non-enveloped virus to propel its entry into the host.
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25
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Chaperone-assisted protein aggregate reactivation: Different solutions for the same problem. Arch Biochem Biophys 2015; 580:121-34. [PMID: 26159839 DOI: 10.1016/j.abb.2015.07.006] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2015] [Revised: 07/02/2015] [Accepted: 07/04/2015] [Indexed: 12/15/2022]
Abstract
The oligomeric AAA+ chaperones Hsp104 in yeast and ClpB in bacteria are responsible for the reactivation of aggregated proteins, an activity essential for cell survival during severe stress. The protein disaggregase activity of these members of the Hsp100 family is linked to the activity of chaperones from the Hsp70 and Hsp40 families. The precise mechanism by which these proteins untangle protein aggregates remains unclear. Strikingly, Hsp100 proteins are not present in metazoans. This does not mean that animal cells do not have a disaggregase activity, but that this activity is performed by the Hsp70 system and a representative of the Hsp110 family instead of a Hsp100 protein. This review describes the actual view of Hsp100-mediated aggregate reactivation, including the ATP-induced conformational changes associated with their disaggregase activity, the dynamics of the oligomeric assembly that is regulated by its ATPase cycle and the DnaK system, and the tight allosteric coupling between the ATPase domains within the hexameric ring complexes. The lack of homologs of these disaggregases in metazoans has suggested that they might be used as potential targets to develop antimicrobials. The current knowledge of the human disaggregase machinery and the role of Hsp110 are also discussed.
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26
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Loureiro CA, Matos AM, Dias-Alves Â, Pereira JF, Uliyakina I, Barros P, Amaral MD, Matos P. A molecular switch in the scaffold NHERF1 enables misfolded CFTR to evade the peripheral quality control checkpoint. Sci Signal 2015; 8:ra48. [PMID: 25990958 DOI: 10.1126/scisignal.aaa1580] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The peripheral protein quality control (PPQC) checkpoint removes improperly folded proteins from the plasma membrane through a mechanism involving the E3 ubiquitin ligase CHIP (carboxyl terminus of Hsc70 interacting protein). PPQC limits the efficacy of some cystic fibrosis (CF) drugs, such as VX-809, that improve trafficking to the plasma membrane of misfolded mutants of the CF transmembrane conductance regulator (CFTR), including F508del-CFTR, which retains partial functionality. We investigated the PPQC checkpoint in lung epithelial cells with F508del-CFTR that were exposed to VX-809. The conformation of the scaffold protein NHERF1 (Na(+)/H(+) exchange regulatory factor 1) determined whether the PPQC recognized "rescued" F508del-CFTR (the portion that reached the cell surface in VX-809-treated cells). Activation of the cytoskeletal regulator Rac1 promoted an interaction between the actin-binding adaptor protein ezrin and NHERF1, triggering exposure of the second PDZ domain of NHERF1, which interacted with rescued F508del-CFTR. Because binding of F508del-CFTR to the second PDZ of NHERF1 precluded the recruitment of CHIP, the coexposure of airway cells to Rac1 activator nearly tripled the efficacy of VX-809. Interference with the NHERF1-ezrin interaction prevented the increase of efficacy of VX-809 by Rac1 activation, but the actin-binding domain of ezrin was not required for the increase in efficacy. Thus, rather than mainly directing anchoring of F508del-CFTR to the actin cytoskeleton, induction of ezrin activation by Rac1 signaling triggered a conformational change in NHERF1, which was then able to bind and stabilize misfolded CFTR at the plasma membrane. These insights into the cell surface stabilization of CFTR provide new targets to improve treatment of CF.
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Affiliation(s)
- Cláudia A Loureiro
- Department of Human Genetics, National Health Institute Doutor Ricardo Jorge, Av. Padre Cruz, 1649-016 Lisboa, Portugal. Biosystems & Integrative Sciences Institute (BioISI), Faculty of Sciences, University of Lisboa, Campo Grande-C8, 1749-016 Lisboa, Portugal
| | - Ana Margarida Matos
- Department of Human Genetics, National Health Institute Doutor Ricardo Jorge, Av. Padre Cruz, 1649-016 Lisboa, Portugal. Biosystems & Integrative Sciences Institute (BioISI), Faculty of Sciences, University of Lisboa, Campo Grande-C8, 1749-016 Lisboa, Portugal
| | - Ângela Dias-Alves
- Department of Human Genetics, National Health Institute Doutor Ricardo Jorge, Av. Padre Cruz, 1649-016 Lisboa, Portugal. Biosystems & Integrative Sciences Institute (BioISI), Faculty of Sciences, University of Lisboa, Campo Grande-C8, 1749-016 Lisboa, Portugal
| | - Joana F Pereira
- Department of Human Genetics, National Health Institute Doutor Ricardo Jorge, Av. Padre Cruz, 1649-016 Lisboa, Portugal. Biosystems & Integrative Sciences Institute (BioISI), Faculty of Sciences, University of Lisboa, Campo Grande-C8, 1749-016 Lisboa, Portugal
| | - Inna Uliyakina
- Biosystems & Integrative Sciences Institute (BioISI), Faculty of Sciences, University of Lisboa, Campo Grande-C8, 1749-016 Lisboa, Portugal
| | - Patrícia Barros
- Department of Human Genetics, National Health Institute Doutor Ricardo Jorge, Av. Padre Cruz, 1649-016 Lisboa, Portugal. Biosystems & Integrative Sciences Institute (BioISI), Faculty of Sciences, University of Lisboa, Campo Grande-C8, 1749-016 Lisboa, Portugal
| | - Margarida D Amaral
- Biosystems & Integrative Sciences Institute (BioISI), Faculty of Sciences, University of Lisboa, Campo Grande-C8, 1749-016 Lisboa, Portugal
| | - Paulo Matos
- Department of Human Genetics, National Health Institute Doutor Ricardo Jorge, Av. Padre Cruz, 1649-016 Lisboa, Portugal. Biosystems & Integrative Sciences Institute (BioISI), Faculty of Sciences, University of Lisboa, Campo Grande-C8, 1749-016 Lisboa, Portugal.
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27
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Bracher A, Verghese J. GrpE, Hsp110/Grp170, HspBP1/Sil1 and BAG domain proteins: nucleotide exchange factors for Hsp70 molecular chaperones. Subcell Biochem 2015; 78:1-33. [PMID: 25487014 DOI: 10.1007/978-3-319-11731-7_1] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Molecular chaperones of the Hsp70 family are key components of the cellular protein folding machinery. Substrate folding is accomplished by iterative cycles of ATP binding, hydrolysis and release. The ATPase activity of Hsp70 is regulated by two main classes of cochaperones: J-domain proteins stimulate ATPase hydrolysis by Hsp70, while nucleotide exchange factors (NEF) facilitate its conversion from the ADP-bound to the ATP-bound state, thus closing the chaperone folding cycle. Beginning with the discovery of the prototypical bacterial NEF GrpE, a large diversity of Hsp70 nucleotide exchange factors has been identified, connecting Hsp70 to a multitude of cellular processes in the eukaryotic cell. Here we review recent advances towards structure and function of nucleotide exchange factors from the Hsp110/Grp170, HspBP1/Sil1 and BAG domain protein families and discuss how these cochaperones connect protein folding with quality control and degradation pathways.
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Affiliation(s)
- Andreas Bracher
- Dept. of Cellular Biochemistry, Max-Planck-Institute of Biochemistry, 82152, Martinsried, Germany,
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28
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Berard AR, Coombs KM, Severini A. Quantification of the host response proteome after herpes simplex virus type 1 infection. J Proteome Res 2015; 14:2121-42. [PMID: 25815715 DOI: 10.1021/pr5012284] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Viruses employ numerous host cell metabolic functions to propagate and manage to evade the host immune system. For herpes simplex virus type 1 (HSV1), a virus that has evolved to efficiently infect humans without seriously harming the host in most cases, the virus-host interaction is specifically interesting. This interaction can be best characterized by studying the proteomic changes that occur in the host during infection. Previous studies have been successful at identifying numerous host proteins that play important roles in HSV infection; however, there is still much that we do not know. This study identifies host metabolic functions and proteins that play roles in HSV infection, using global quantitative stable isotope labeling by amino acids in cell culture (SILAC) proteomic profiling of the host cell combined with LC-MS/MS. We showed differential proteins during early, mid and late infection, using both cytosolic and nuclear fractions. We identified hundreds of differentially regulated proteins involved in fundamental cellular functions, including gene expression, DNA replication, inflammatory response, cell movement, cell death, and RNA post-transcriptional modification. Novel differentially regulated proteins in HSV infections include some previously identified in other virus systems, as well as fusion protein, involved in malignant liposarcoma (FUS) and hypoxia up-regulated 1 protein precursor (HYOU1), which have not been identified previously in any virus infection.
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Affiliation(s)
- Alicia R Berard
- †Department of Medical Microbiology, Faculty of Medicine, University of Manitoba, Winnipeg, Manitoba, Canada R3E 0J9.,‡Manitoba Center for Proteomics and Systems Biology, University of Manitoba, Room 799 John Buhler Research Centre, Winnipeg, Manitoba, Canada R3E 3P4
| | - Kevin M Coombs
- †Department of Medical Microbiology, Faculty of Medicine, University of Manitoba, Winnipeg, Manitoba, Canada R3E 0J9.,‡Manitoba Center for Proteomics and Systems Biology, University of Manitoba, Room 799 John Buhler Research Centre, Winnipeg, Manitoba, Canada R3E 3P4.,§Manitoba Institute of Child Health, University of Manitoba, Room 641 John Buhler Research Centre, Winnipeg, Manitoba, Canada R3E 3P4
| | - Alberto Severini
- †Department of Medical Microbiology, Faculty of Medicine, University of Manitoba, Winnipeg, Manitoba, Canada R3E 0J9.,∥National Microbiology Laboratory, Public Health Agency of Canada, 1015 Arlington Street, Winnipeg, Manitoba, Canada R3E 3P6
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29
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Bracher A, Verghese J. The nucleotide exchange factors of Hsp70 molecular chaperones. Front Mol Biosci 2015; 2:10. [PMID: 26913285 PMCID: PMC4753570 DOI: 10.3389/fmolb.2015.00010] [Citation(s) in RCA: 138] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2015] [Accepted: 03/18/2015] [Indexed: 11/13/2022] Open
Abstract
Molecular chaperones of the Hsp70 family form an important hub in the cellular protein folding networks in bacteria and eukaryotes, connecting translation with the downstream machineries of protein folding and degradation. The Hsp70 folding cycle is driven by two types of cochaperones: J-domain proteins stimulate ATP hydrolysis by Hsp70, while nucleotide exchange factors (NEFs) promote replacement of Hsp70-bound ADP with ATP. Bacteria and organelles of bacterial origin have only one known NEF type for Hsp70, GrpE. In contrast, a large diversity of Hsp70 NEFs has been discovered in the eukaryotic cell. These NEFs belong to the Hsp110/Grp170, HspBP1/Sil1, and BAG domain protein families. In this short review we compare the structures and molecular mechanisms of nucleotide exchange factors for Hsp70 and discuss how these cochaperones contribute to protein folding and quality control in the cell.
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Affiliation(s)
- Andreas Bracher
- Department of Cellular Biochemistry, Max-Planck-Institute of Biochemistry Martinsried, Germany
| | - Jacob Verghese
- Department of Cellular Biochemistry, Max-Planck-Institute of Biochemistry Martinsried, Germany
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30
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Young JC. The role of the cytosolic HSP70 chaperone system in diseases caused by misfolding and aberrant trafficking of ion channels. Dis Model Mech 2015; 7:319-29. [PMID: 24609033 PMCID: PMC3944492 DOI: 10.1242/dmm.014001] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Protein-folding diseases are an ongoing medical challenge. Many diseases within this group are genetically determined, and have no known cure. Among the examples in which the underlying cellular and molecular mechanisms are well understood are diseases driven by misfolding of transmembrane proteins that normally function as cell-surface ion channels. Wild-type forms are synthesized and integrated into the endoplasmic reticulum (ER) membrane system and, upon correct folding, are trafficked by the secretory pathway to the cell surface. Misfolded mutant forms traffic poorly, if at all, and are instead degraded by the ER-associated proteasomal degradation (ERAD) system. Molecular chaperones can assist the folding of the cytosolic domains of these transmembrane proteins; however, these chaperones are also involved in selecting misfolded forms for ERAD. Given this dual role of chaperones, diseases caused by the misfolding and aberrant trafficking of ion channels (referred to here as ion-channel-misfolding diseases) can be regarded as a consequence of insufficiency of the pro-folding chaperone activity and/or overefficiency of the chaperone ERAD role. An attractive idea is that manipulation of the chaperones might allow increased folding and trafficking of the mutant proteins, and thereby partial restoration of function. This Review outlines the roles of the cytosolic HSP70 chaperone system in the best-studied paradigms of ion-channel-misfolding disease--the CFTR chloride channel in cystic fibrosis and the hERG potassium channel in cardiac long QT syndrome type 2. In addition, other ion channels implicated in ion-channel-misfolding diseases are discussed.
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Affiliation(s)
- Jason C Young
- McGill University, Department of Biochemistry, Groupe de Recherche Axé sur la Structure des Protéines, 3649 Promenade Sir William Osler, Montreal, QC H3G 0B1, Canada
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31
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Interference with ubiquitination in CFTR modifies stability of core glycosylated and cell surface pools. Mol Cell Biol 2014; 34:2554-65. [PMID: 24777605 DOI: 10.1128/mcb.01042-13] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
It is recognized that both wild-type and mutant CFTR proteins undergo ubiquitination at multiple lysines in the proteins and in one or more subcellular locations. We hypothesized that ubiquitin is added to specific sites in wild-type CFTR to stabilize it and at other sites to signal for proteolysis. Mass spectrometric analysis of wild-type CFTR identified ubiquitinated lysines 68, 710, 716, 1041, and 1080. We demonstrate that the ubiquitinated K710, K716, and K1041 residues stabilize wild-type CFTR, protecting it from proteolysis. The polyubiquitin linkage is predominantly K63. N-tail mutants, K14R and K68R, lead to increased mature band CCFTR, which can be augmented by proteasomal (but not lysosomal) inhibition, allowing trafficking to the surface. The amount of CFTR in the K1041R mutant was drastically reduced and consisted of bands A/B, suggesting that the site in transmembrane 10 (TM10) was critical to further processing beyond the proteasome. The K1218R mutant increases total and cell surface CFTR, which is further accumulated by proteasomal and lysosomal inhibition. Thus, ubiquitination at residue 1218 may destabilize wild-type CFTR in both the endoplasmic reticulum (ER) and recycling pools. Small molecules targeting the region of residue 1218 to block ubiquitination or to preserving structure at residues 710 to 716 might be protein sparing for some forms of cystic fibrosis.
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32
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Huang X, Hernandez CC, Hu N, Macdonald RL. Three epilepsy-associated GABRG2 missense mutations at the γ+/β- interface disrupt GABAA receptor assembly and trafficking by similar mechanisms but to different extents. Neurobiol Dis 2014; 68:167-79. [PMID: 24798517 PMCID: PMC4169075 DOI: 10.1016/j.nbd.2014.04.015] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2014] [Revised: 04/22/2014] [Accepted: 04/25/2014] [Indexed: 11/23/2022] Open
Abstract
We compared the effects of three missense mutations in the GABAA receptor γ2 subunit on GABAA receptor assembly, trafficking and function in HEK293T cells cotransfected with α1, β2, and wildtype or mutant γ2 subunits. The mutations R82Q and P83S were identified in families with genetic epilepsy with febrile seizures plus (GEFS+), and N79S was found in a single patient with generalized tonic-clonic seizures (GTCS). Although all three mutations were located in an N-terminal loop that contributes to the γ+/β- subunit-subunit interface, we found that each mutation impaired GABAA receptor assembly to a different extent. The γ2(R82Q) and γ2(P83S) subunits had reduced α1β2γ2 receptor surface expression due to impaired assembly into pentamers, endoplasmic reticulum (ER) retention and degradation. In contrast, γ2(N79S) subunits were efficiently assembled into GABAA receptors with only minimally altered receptor trafficking, suggesting that N79S was a rare or susceptibility variant rather than an epilepsy mutation. Increased structural variability at assembly motifs was predicted by R82Q and P83S, but not N79S, substitution, suggesting that R82Q and P83S substitutions were less tolerated. Membrane proteins with missense mutations that impair folding and assembly often can be "rescued" by decreased temperatures. We coexpressed wildtype or mutant γ2 subunits with α1 and β2 subunits and found increased surface and total levels of both wildtype and mutant γ2 subunits after decreasing the incubation temperature to 30°C for 24h, suggesting that lower temperatures increased GABAA receptor stability. Thus epilepsy-associated mutations N79S, R82Q and P83S disrupted GABAA receptor assembly to different extents, an effect that could be potentially rescued by facilitating protein folding and assembly.
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Affiliation(s)
- Xuan Huang
- The Graduate Program of Neuroscience, Vanderbilt University Medical Center, Nashville, TN 37212, USA; Departments of Neurology, Vanderbilt University Medical Center, Nashville, TN 37212, USA
| | - Ciria C Hernandez
- Departments of Neurology, Vanderbilt University Medical Center, Nashville, TN 37212, USA
| | - Ningning Hu
- Departments of Neurology, Vanderbilt University Medical Center, Nashville, TN 37212, USA
| | - Robert L Macdonald
- The Graduate Program of Neuroscience, Vanderbilt University Medical Center, Nashville, TN 37212, USA; Departments of Neurology, Vanderbilt University Medical Center, Nashville, TN 37212, USA.
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33
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Robinson N, Baranski M, Mahapatra KD, Saha JN, Das S, Mishra J, Das P, Kent M, Arnyasi M, Sahoo PK. A linkage map of transcribed single nucleotide polymorphisms in rohu (Labeo rohita) and QTL associated with resistance to Aeromonas hydrophila. BMC Genomics 2014; 15:541. [PMID: 24984705 PMCID: PMC4226992 DOI: 10.1186/1471-2164-15-541] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2013] [Accepted: 06/17/2014] [Indexed: 11/22/2022] Open
Abstract
BACKGROUND Production of carp dominates world aquaculture. More than 1.1 million tonnes of rohu carp, Labeo rohita (Hamilton), were produced in 2010. Aeromonas hydrophila is a bacterial pathogen causing aeromoniasis in rohu, and is a major problem for carp production worldwide. There is a need to better understand the genetic mechanisms affecting resistance to this disease, and to develop tools that can be used with selective breeding to improve resistance. Here we use a 6 K SNP array to genotype 21 full-sibling families of L. rohita that were experimentally challenged intra-peritoneally with a virulent strain of A. hydrophila to scan the genome for quantitative trait loci associated with disease resistance. RESULTS In all, 3193 SNPs were found to be informative and were used to create a linkage map and to scan for QTL affecting resistance to A. hydrophila. The linkage map consisted of 25 linkage groups, corresponding to the number of haploid chromosomes in L. rohita. Male and female linkage maps were similar in terms of order, coverage (1384 and 1393 cM, respectively) and average interval distances (1.32 and 1.35 cM, respectively). Forty-one percent of the SNPs were annotated with gene identity using BLAST (cut off E-score of 0.001). Twenty-one SNPs mapping to ten linkage groups showed significant associations with the traits hours of survival and dead or alive (P <0.05 after Bonferroni correction). Of the SNPs showing significant or suggestive associations with the traits, several were homologous to genes of known immune function or were in close linkage to such genes. Genes of interest included heat shock proteins (70, 60, 105 and "small heat shock proteins"), mucin (5b precursor and 2), lectin (receptor and CD22), tributyltin-binding protein, major histocompatibility loci (I and II), complement protein component c7-1, perforin 1, ubiquitin (ligase, factor e4b isoform 2 and conjugation enzyme e2 c), proteasome subunit, T-cell antigen receptor and lymphocyte specific protein tyrosine kinase. CONCLUSIONS A panel of markers has been identified that will be validated for use with both genomic and marker-assisted selection to improve resistance of L. rohita to A. hydrophila.
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Affiliation(s)
- Nicholas Robinson
- Breeding and Genetics, Nofima, PO Box 5010, 1432 Ås, Norway
- Biological Sciences, Flinders University, Bedford Park, Australia
| | | | - Kanta Das Mahapatra
- Central Institute of Freshwater Aquaculture, Kausalyaganga, Bhubaneswar, India
| | - Jatindra Nath Saha
- Central Institute of Freshwater Aquaculture, Kausalyaganga, Bhubaneswar, India
| | - Sweta Das
- Central Institute of Freshwater Aquaculture, Kausalyaganga, Bhubaneswar, India
| | - Jashobanta Mishra
- Central Institute of Freshwater Aquaculture, Kausalyaganga, Bhubaneswar, India
| | - Paramananda Das
- Central Institute of Freshwater Aquaculture, Kausalyaganga, Bhubaneswar, India
| | - Matthew Kent
- Centre for Integrative Genetics, University of Life Sciences, Ås, Norway
| | - Mariann Arnyasi
- Centre for Integrative Genetics, University of Life Sciences, Ås, Norway
| | - Pramoda Kumar Sahoo
- Central Institute of Freshwater Aquaculture, Kausalyaganga, Bhubaneswar, India
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34
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Abrams JL, Verghese J, Gibney PA, Morano KA. Hierarchical functional specificity of cytosolic heat shock protein 70 (Hsp70) nucleotide exchange factors in yeast. J Biol Chem 2014; 289:13155-67. [PMID: 24671421 DOI: 10.1074/jbc.m113.530014] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Heat shock protein 70 (Hsp70) molecular chaperones play critical roles in protein homeostasis. In the budding yeast Saccharomyces cerevisiae, cytosolic Hsp70 interacts with up to three types of nucleotide exchange factors (NEFs) homologous to human counterparts: Sse1/Sse2 (Heat shock protein 110 (Hsp110)), Fes1 (HspBP1), and Snl1 (Bag-1). All three NEFs stimulate ADP release; however, it is unclear why multiple distinct families have been maintained throughout eukaryotic evolution. In this study we investigate NEF roles in Hsp70 cell biology using an isogenic combinatorial collection of NEF deletion mutants. Utilizing well characterized model substrates, we find that Sse1 participates in most Hsp70-mediated processes and is of particular importance in protein biogenesis and degradation, whereas Fes1 contributes to a minimal extent. Surprisingly, disaggregation and resolubilization of thermally denatured firefly luciferase occurred independently of NEF activity. Simultaneous deletion of SSE1 and FES1 resulted in constitutive activation of heat shock protein expression mediated by the transcription factor Hsf1, suggesting that these two factors are important for modulating stress response. Fes1 was found to interact in vivo preferentially with the Ssa family of cytosolic Hsp70 and not the co-translational Ssb homolog, consistent with the lack of cold sensitivity and protein biogenesis phenotypes for fes1Δ cells. No significant consequence could be attributed to deletion of the minor Hsp110 SSE2 or the Bag homolog SNL1. Together, these lines of investigation provide a comparative analysis of NEF function in yeast that implies Hsp110 is the principal NEF for cytosolic Hsp70, making it an ideal candidate for therapeutic intervention in human protein folding disorders.
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Affiliation(s)
- Jennifer L Abrams
- From the Department of Microbiology and Molecular Genetics, University of Texas Medical School, Houston, Texas 77030
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35
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Rauch JN, Gestwicki JE. Binding of human nucleotide exchange factors to heat shock protein 70 (Hsp70) generates functionally distinct complexes in vitro. J Biol Chem 2013; 289:1402-14. [PMID: 24318877 DOI: 10.1074/jbc.m113.521997] [Citation(s) in RCA: 114] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Proteins with Bcl2-associated anthanogene (BAG) domains act as nucleotide exchange factors (NEFs) for the molecular chaperone heat shock protein 70 (Hsp70). There are six BAG family NEFs in humans, and each is thought to link Hsp70 to a distinct cellular pathway. However, little is known about how the NEFs compete for binding to Hsp70 or how they might differentially shape its biochemical activities. Toward these questions, we measured the binding of human Hsp72 (HSPA1A) to BAG1, BAG2, BAG3, and the unrelated NEF Hsp105. These studies revealed a clear hierarchy of affinities: BAG3 > BAG1 > Hsp105 ≫ BAG2. All of the NEFs competed for binding to Hsp70, and their relative affinity values predicted their potency in nucleotide and peptide release assays. Finally, we combined the Hsp70-NEF pairs with cochaperones of the J protein family (DnaJA1, DnaJA2, DnaJB1, and DnaJB4) to generate 16 permutations. The activity of the combinations in ATPase and luciferase refolding assays were dependent on the identity and stoichiometry of both the J protein and NEF so that some combinations were potent chaperones, whereas others were inactive. Given the number and diversity of cochaperones in mammals, it is likely that combinatorial assembly could generate a large number of distinct permutations.
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Affiliation(s)
- Jennifer N Rauch
- From the Departments of Biochemistry and Pathology and the Life Sciences Institute, University of Michigan, Ann Arbor, Michigan 48109 and
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Kuo Y, Ren S, Lao U, Edgar BA, Wang T. Suppression of polyglutamine protein toxicity by co-expression of a heat-shock protein 40 and a heat-shock protein 110. Cell Death Dis 2013; 4:e833. [PMID: 24091676 PMCID: PMC3824661 DOI: 10.1038/cddis.2013.351] [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: 05/14/2013] [Revised: 07/29/2013] [Accepted: 08/12/2013] [Indexed: 01/17/2023]
Abstract
A network of heat-shock proteins mediates cellular protein homeostasis, and has a fundamental role in preventing aggregation-associated neurodegenerative diseases. In a Drosophila model of polyglutamine (polyQ) disease, the HSP40 family protein, DNAJ-1, is a superior suppressor of toxicity caused by the aggregation of polyQ containing proteins. Here, we demonstrate that one specific HSP110 protein, 70 kDa heat-shock cognate protein cb (HSC70cb), interacts physically and genetically with DNAJ-1 in vivo, and that HSC70cb is necessary for DNAJ-1 to suppress polyglutamine-induced cell death in Drosophila. Expression of HSC70cb together with DNAJ-1 significantly enhanced the suppressive effects of DNAJ-1 on polyQ-induced neurodegeneration, whereas expression of HSC70cb alone did not suppress neurodegeneration in Drosophila models of either general polyQ disease or Huntington's disease. Furthermore, expression of a human HSP40, DNAJB1, together with a human HSP110, APG-1, protected cells from polyQ-induced neural degeneration in flies, whereas expression of either component alone had little effect. Our data provide a functional link between HSP40 and HSP110 in suppressing the cytotoxicity of aggregation-prone proteins, and suggest that HSP40 and HSP110 function together in protein homeostasis control.
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Affiliation(s)
- Y Kuo
- Division of Basic Sciences, National Institute of Biological Sciences, Beijing, China
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Wang XY, Subjeck JR. High molecular weight stress proteins: Identification, cloning and utilisation in cancer immunotherapy. Int J Hyperthermia 2013; 29:364-75. [PMID: 23829534 DOI: 10.3109/02656736.2013.803607] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Although the large stress/heat shock proteins (HSPs), i.e. Hsp110 and Grp170, were identified over 30 years ago, these abundant and highly conserved molecules have received much less attention compared to other conventional HSPs. Large stress proteins act as molecular chaperones with exceptional protein-holding capability and prevent the aggregation of proteins induced by thermal stress. The chaperoning properties of Hsp110 and Grp170 are integral to the ability of these molecules to modulate immune functions and are essential for developing large chaperone complex vaccines for cancer immunotherapy. The potent anti-tumour activity of the Hsp110/Grp170-tumour protein antigen complexes demonstrated in preclinical studies has led to a phase I clinical trial through the National Cancer Institute's rapid access to intervention development (RAID) programme that is presently underway. Here we review aspects of the structure and function of these large stress proteins, their roles as molecular chaperones in the biology of cell stress, and prospects for their use in immune regulation and cancer immunotherapy. Lastly, we will discuss the recently revealed immunosuppressive activity of scavenger receptor A that binds to Hsp110 and Grp170, as well as the feasibility of targeting this receptor to promote T-cell activation and anti-tumour immunity induced by large HSP vaccines and other immunotherapies.
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Affiliation(s)
- Xiang-Yang Wang
- Department of Human Molecular Genetics, Massey Cancer Center, Virginia Commonwealth University, Richmond, Virginia, USA
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