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Müller L, Hoppe T. UPS-dependent strategies of protein quality control degradation. Trends Biochem Sci 2024:S0968-0004(24)00149-X. [PMID: 38945729 DOI: 10.1016/j.tibs.2024.06.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2024] [Revised: 05/29/2024] [Accepted: 06/10/2024] [Indexed: 07/02/2024]
Abstract
The degradation of damaged proteins is critical for tissue integrity and organismal health because damaged proteins have a high propensity to form aggregates. E3 ubiquitin ligases are key regulators of protein quality control (PQC) and mediate the selective degradation of damaged proteins, a process termed 'PQC degradation' (PQCD). The degradation signals (degrons) that trigger PQCD are based on hydrophobic sites that are normally buried within the native protein structure. However, an open question is how PQCD-specialized E3 ligases distinguish between transiently misfolded proteins, which can be efficiently refolded, and permanently damaged proteins, which must be degraded. While significant progress has been made in characterizing degradation determinants, understanding the key regulatory signals of cellular and organismal PQCD pathways remains a challenge.
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Affiliation(s)
- Leonie Müller
- Institute for Genetics, University of Cologne, 50674 Cologne, Germany; Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, 50931 Cologne, Germany; Center for Molecular Medicine Cologne (CMMC), Faculty of Medicine and University Hospital of Cologne, 50931 Cologne, Germany
| | - Thorsten Hoppe
- Institute for Genetics, University of Cologne, 50674 Cologne, Germany; Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, 50931 Cologne, Germany; Center for Molecular Medicine Cologne (CMMC), Faculty of Medicine and University Hospital of Cologne, 50931 Cologne, Germany.
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2
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Clausen L, Okarmus J, Voutsinos V, Meyer M, Lindorff-Larsen K, Hartmann-Petersen R. PRKN-linked familial Parkinson's disease: cellular and molecular mechanisms of disease-linked variants. Cell Mol Life Sci 2024; 81:223. [PMID: 38767677 PMCID: PMC11106057 DOI: 10.1007/s00018-024-05262-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2024] [Revised: 04/25/2024] [Accepted: 05/02/2024] [Indexed: 05/22/2024]
Abstract
Parkinson's disease (PD) is a common and incurable neurodegenerative disorder that arises from the loss of dopaminergic neurons in the substantia nigra and is mainly characterized by progressive loss of motor function. Monogenic familial PD is associated with highly penetrant variants in specific genes, notably the PRKN gene, where homozygous or compound heterozygous loss-of-function variants predominate. PRKN encodes Parkin, an E3 ubiquitin-protein ligase important for protein ubiquitination and mitophagy of damaged mitochondria. Accordingly, Parkin plays a central role in mitochondrial quality control but is itself also subject to a strict protein quality control system that rapidly eliminates certain disease-linked Parkin variants. Here, we summarize the cellular and molecular functions of Parkin, highlighting the various mechanisms by which PRKN gene variants result in loss-of-function. We emphasize the importance of high-throughput assays and computational tools for the clinical classification of PRKN gene variants and how detailed insights into the pathogenic mechanisms of PRKN gene variants may impact the development of personalized therapeutics.
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Affiliation(s)
- Lene Clausen
- Department of Biology, Linderstrøm-Lang Centre for Protein Science, University of Copenhagen, 2200, Copenhagen, Denmark
| | - Justyna Okarmus
- Department of Neurobiology Research, Institute of Molecular Medicine, University of Southern Denmark, 5230, Odense, Denmark
| | - Vasileios Voutsinos
- Department of Biology, Linderstrøm-Lang Centre for Protein Science, University of Copenhagen, 2200, Copenhagen, Denmark
| | - Morten Meyer
- Department of Neurobiology Research, Institute of Molecular Medicine, University of Southern Denmark, 5230, Odense, Denmark
- Department of Neurology, Odense University Hospital, 5000, Odense, Denmark
- Department of Clinical Research, BRIDGE, Brain Research Inter Disciplinary Guided Excellence, University of Southern Denmark, 5230, Odense, Denmark
| | - Kresten Lindorff-Larsen
- Department of Biology, Linderstrøm-Lang Centre for Protein Science, University of Copenhagen, 2200, Copenhagen, Denmark
| | - Rasmus Hartmann-Petersen
- Department of Biology, Linderstrøm-Lang Centre for Protein Science, University of Copenhagen, 2200, Copenhagen, Denmark.
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3
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Grønbæk-Thygesen M, Voutsinos V, Johansson KE, Schulze TK, Cagiada M, Pedersen L, Clausen L, Nariya S, Powell RL, Stein A, Fowler DM, Lindorff-Larsen K, Hartmann-Petersen R. Deep mutational scanning reveals a correlation between degradation and toxicity of thousands of aspartoacylase variants. Nat Commun 2024; 15:4026. [PMID: 38740822 DOI: 10.1038/s41467-024-48481-0] [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: 10/18/2023] [Accepted: 05/02/2024] [Indexed: 05/16/2024] Open
Abstract
Unstable proteins are prone to form non-native interactions with other proteins and thereby may become toxic. To mitigate this, destabilized proteins are targeted by the protein quality control network. Here we present systematic studies of the cytosolic aspartoacylase, ASPA, where variants are linked to Canavan disease, a lethal neurological disorder. We determine the abundance of 6152 of the 6260 ( ~ 98%) possible single amino acid substitutions and nonsense ASPA variants in human cells. Most low abundance variants are degraded through the ubiquitin-proteasome pathway and become toxic upon prolonged expression. The data correlates with predicted changes in thermodynamic stability, evolutionary conservation, and separate disease-linked variants from benign variants. Mapping of degradation signals (degrons) shows that these are often buried and the C-terminal region functions as a degron. The data can be used to interpret Canavan disease variants and provide insight into the relationship between protein stability, degradation and cell fitness.
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Affiliation(s)
- Martin Grønbæk-Thygesen
- Linderstrøm-Lang Centre for Protein Science, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Vasileios Voutsinos
- Linderstrøm-Lang Centre for Protein Science, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Kristoffer E Johansson
- Linderstrøm-Lang Centre for Protein Science, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Thea K Schulze
- Linderstrøm-Lang Centre for Protein Science, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Matteo Cagiada
- Linderstrøm-Lang Centre for Protein Science, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Line Pedersen
- Linderstrøm-Lang Centre for Protein Science, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Lene Clausen
- Linderstrøm-Lang Centre for Protein Science, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Snehal Nariya
- Department of Genome Sciences, University of Washington, Seattle, WA, USA
| | - Rachel L Powell
- Department of Genome Sciences, University of Washington, Seattle, WA, USA
| | - Amelie Stein
- Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Douglas M Fowler
- Department of Genome Sciences, University of Washington, Seattle, WA, USA.
- Department of Bioengineering, University of Washington, Seattle, WA, USA.
| | - Kresten Lindorff-Larsen
- Linderstrøm-Lang Centre for Protein Science, Department of Biology, University of Copenhagen, Copenhagen, Denmark.
| | - Rasmus Hartmann-Petersen
- Linderstrøm-Lang Centre for Protein Science, Department of Biology, University of Copenhagen, Copenhagen, Denmark.
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4
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Clausen L, Voutsinos V, Cagiada M, Johansson KE, Grønbæk-Thygesen M, Nariya S, Powell RL, Have MKN, Oestergaard VH, Stein A, Fowler DM, Lindorff-Larsen K, Hartmann-Petersen R. A mutational atlas for Parkin proteostasis. Nat Commun 2024; 15:1541. [PMID: 38378758 PMCID: PMC10879094 DOI: 10.1038/s41467-024-45829-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Accepted: 02/01/2024] [Indexed: 02/22/2024] Open
Abstract
Proteostasis can be disturbed by mutations affecting folding and stability of the encoded protein. An example is the ubiquitin ligase Parkin, where gene variants result in autosomal recessive Parkinsonism. To uncover the pathological mechanism and provide comprehensive genotype-phenotype information, variant abundance by massively parallel sequencing (VAMP-seq) is leveraged to quantify the abundance of Parkin variants in cultured human cells. The resulting mutational map, covering 9219 out of the 9300 possible single-site amino acid substitutions and nonsense Parkin variants, shows that most low abundance variants are proteasome targets and are located within the structured domains of the protein. Half of the known disease-linked variants are found at low abundance. Systematic mapping of degradation signals (degrons) reveals an exposed degron region proximal to the so-called "activation element". This work provides examples of how missense variants may cause degradation either via destabilization of the native protein, or by introducing local signals for degradation.
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Affiliation(s)
- Lene Clausen
- Linderstrøm-Lang Centre for Protein Science, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Vasileios Voutsinos
- Linderstrøm-Lang Centre for Protein Science, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Matteo Cagiada
- Linderstrøm-Lang Centre for Protein Science, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Kristoffer E Johansson
- Linderstrøm-Lang Centre for Protein Science, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Martin Grønbæk-Thygesen
- Linderstrøm-Lang Centre for Protein Science, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Snehal Nariya
- Department of Genome Sciences, University of Washington, Seattle, WA, USA
| | - Rachel L Powell
- Department of Genome Sciences, University of Washington, Seattle, WA, USA
| | - Magnus K N Have
- Linderstrøm-Lang Centre for Protein Science, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | | | - Amelie Stein
- Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Douglas M Fowler
- Department of Genome Sciences, University of Washington, Seattle, WA, USA.
- Department of Bioengineering, University of Washington, Seattle, WA, USA.
| | - Kresten Lindorff-Larsen
- Linderstrøm-Lang Centre for Protein Science, Department of Biology, University of Copenhagen, Copenhagen, Denmark.
| | - Rasmus Hartmann-Petersen
- Linderstrøm-Lang Centre for Protein Science, Department of Biology, University of Copenhagen, Copenhagen, Denmark.
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5
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Paul AA, Szulc NA, Kobiela A, Brown SJ, Pokrzywa W, Gutowska-Owsiak D. In silico analysis of the profilaggrin sequence indicates alterations in the stability, degradation route, and intracellular protein fate in filaggrin null mutation carriers. Front Mol Biosci 2023; 10:1105678. [PMID: 37200867 PMCID: PMC10185843 DOI: 10.3389/fmolb.2023.1105678] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Accepted: 04/19/2023] [Indexed: 05/20/2023] Open
Abstract
Background: Loss of function mutation in FLG is the major genetic risk factor for atopic dermatitis (AD) and other allergic manifestations. Presently, little is known about the cellular turnover and stability of profilaggrin, the protein encoded by FLG. Since ubiquitination directly regulates the cellular fate of numerous proteins, their degradation and trafficking, this process could influence the concentration of filaggrin in the skin. Objective: To determine the elements mediating the interaction of profilaggrin with the ubiquitin-proteasome system (i.e., degron motifs and ubiquitination sites), the features responsible for its stability, and the effect of nonsense and frameshift mutations on profilaggrin turnover. Methods: The effect of inhibition of proteasome and deubiquitinases on the level and modifications of profilaggrin and processed products was assessed by immunoblotting. Wild-type profilaggrin sequence and its mutated variants were analysed in silico using the DEGRONOPEDIA and Clustal Omega tool. Results: Inhibition of proteasome and deubiquitinases stabilizes profilaggrin and its high molecular weight of presumably ubiquitinated derivatives. In silico analysis of the sequence determined that profilaggrin contains 18 known degron motifs as well as multiple canonical and non-canonical ubiquitination-prone residues. FLG mutations generate products with increased stability scores, altered usage of the ubiquitination marks, and the frequent appearance of novel degrons, including those promoting C-terminus-mediated degradation routes. Conclusion: The proteasome is involved in the turnover of profilaggrin, which contains multiple degrons and ubiquitination-prone residues. FLG mutations alter those key elements, affecting the degradation routes and the mutated products' stability.
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Affiliation(s)
- Argho Aninda Paul
- Experimental and Translational Immunology Group, Intercollegiate Faculty of Biotechnology of University of Gdansk and Medical University of Gdansk, University of Gdansk, Gdansk, Poland
| | - Natalia A. Szulc
- Laboratory of Protein Metabolism, International Institute of Molecular and Cell Biology in Warsaw, Warsaw, Poland
| | - Adrian Kobiela
- Experimental and Translational Immunology Group, Intercollegiate Faculty of Biotechnology of University of Gdansk and Medical University of Gdansk, University of Gdansk, Gdansk, Poland
| | - Sara J. Brown
- Centre for Genomic and Experimental Medicine, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh, United Kingdom
| | - Wojciech Pokrzywa
- Laboratory of Protein Metabolism, International Institute of Molecular and Cell Biology in Warsaw, Warsaw, Poland
| | - Danuta Gutowska-Owsiak
- Experimental and Translational Immunology Group, Intercollegiate Faculty of Biotechnology of University of Gdansk and Medical University of Gdansk, University of Gdansk, Gdansk, Poland
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6
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Dai Y, Farag M, Lee D, Zeng X, Kim K, Son HI, Guo X, Su J, Peterson N, Mohammed J, Ney M, Shapiro DM, Pappu RV, Chilkoti A, You L. Programmable synthetic biomolecular condensates for cellular control. Nat Chem Biol 2023; 19:518-528. [PMID: 36747054 PMCID: PMC10786170 DOI: 10.1038/s41589-022-01252-8] [Citation(s) in RCA: 27] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2022] [Accepted: 12/21/2022] [Indexed: 02/08/2023]
Abstract
The formation of biomolecular condensates mediated by a coupling of associative and segregative phase transitions plays a critical role in controlling diverse cellular functions in nature. This has inspired the use of phase transitions to design synthetic systems. While design rules of phase transitions have been established for many synthetic intrinsically disordered proteins, most efforts have focused on investigating their phase behaviors in a test tube. Here, we present a rational engineering approach to program the formation and physical properties of synthetic condensates to achieve intended cellular functions. We demonstrate this approach through targeted plasmid sequestration and transcription regulation in bacteria and modulation of a protein circuit in mammalian cells. Our approach lays the foundation for engineering designer condensates for synthetic biology applications.
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Affiliation(s)
- Yifan Dai
- Department of Biomedical Engineering, Pratt School of Engineering, Duke University, Durham, NC, USA
- Duke Center for Quantitative Biodesign, Duke University, Durham, NC, USA
| | - Mina Farag
- Department of Biomedical Engineering, Center for Biomolecular Condensates (CBC), James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, USA
| | - Dongheon Lee
- Department of Biomedical Engineering, Pratt School of Engineering, Duke University, Durham, NC, USA
| | - Xiangze Zeng
- Department of Biomedical Engineering, Center for Biomolecular Condensates (CBC), James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, USA
| | - Kyeri Kim
- Department of Biomedical Engineering, Pratt School of Engineering, Duke University, Durham, NC, USA
| | - Hye-In Son
- Department of Biomedical Engineering, Pratt School of Engineering, Duke University, Durham, NC, USA
| | - Xiao Guo
- Department of Biomedical Engineering, Pratt School of Engineering, Duke University, Durham, NC, USA
| | - Jonathan Su
- Department of Biomedical Engineering, Pratt School of Engineering, Duke University, Durham, NC, USA
| | - Nikhil Peterson
- Department of Biomedical Engineering, Pratt School of Engineering, Duke University, Durham, NC, USA
| | - Javid Mohammed
- Department of Immunology, Duke University, Durham, NC, USA
| | - Max Ney
- Department of Biomedical Engineering, Pratt School of Engineering, Duke University, Durham, NC, USA
| | - Daniel Mark Shapiro
- Department of Biomedical Engineering, Pratt School of Engineering, Duke University, Durham, NC, USA
| | - Rohit V Pappu
- Department of Biomedical Engineering, Center for Biomolecular Condensates (CBC), James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, USA
| | - Ashutosh Chilkoti
- Department of Biomedical Engineering, Pratt School of Engineering, Duke University, Durham, NC, USA.
- Duke Center for Quantitative Biodesign, Duke University, Durham, NC, USA.
| | - Lingchong You
- Department of Biomedical Engineering, Pratt School of Engineering, Duke University, Durham, NC, USA.
- Duke Center for Quantitative Biodesign, Duke University, Durham, NC, USA.
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7
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Johansson KE, Mashahreh B, Hartmann-Petersen R, Ravid T, Lindorff-Larsen K. Prediction of Quality-control Degradation Signals in Yeast Proteins. J Mol Biol 2023; 435:167915. [PMID: 36495918 DOI: 10.1016/j.jmb.2022.167915] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Revised: 11/26/2022] [Accepted: 12/01/2022] [Indexed: 12/12/2022]
Abstract
Effective proteome homeostasis is key to cellular and organismal survival, and cells therefore contain efficient quality control systems to monitor and remove potentially toxic misfolded proteins. Such general protein quality control to a large extent relies on the efficient and robust delivery of misfolded or unfolded proteins to the ubiquitin-proteasome system. This is achieved via recognition of so-called degradation motifs-degrons-that are assumed to become exposed as a result of protein misfolding. Despite their importance, the nature and sequence properties of quality-control degrons remain elusive. Here, we have used data from a yeast-based screen of 23,600 17-residue peptides to build a predictor of quality-control degrons. The resulting model, QCDPred (Quality Control Degron Prediction), achieves good accuracy using only the sequence composition of the peptides as input. Our analysis reveals that strong degrons are enriched in hydrophobic amino acids and depleted in negatively charged amino acids, in line with the expectation that they are buried in natively folded proteins. We applied QCDPred to the yeast proteome, enabling us to analyse more widely the potential effects of degrons. As an example, we show a correlation between cellular abundance and degron potential in disordered regions of proteins. Together with recent results on membrane proteins, our work suggest that the recognition of exposed hydrophobic residues is a key and generic mechanism for proteome homeostasis. QCDPred is freely available as open source code and via a web interface.
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Affiliation(s)
- Kristoffer E Johansson
- Linderstrøm-Lang Centre for Protein Science, Section for Biomolecular Sciences, Department of Biology, University for Copenhagen, Copenhagen, Denmark. https://twitter.com/kristofferenoee
| | - Bayan Mashahreh
- Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Rasmus Hartmann-Petersen
- Linderstrøm-Lang Centre for Protein Science, Section for Biomolecular Sciences, Department of Biology, University for Copenhagen, Copenhagen, Denmark. https://twitter.com/rasmushartmannp
| | - Tommer Ravid
- Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel.
| | - Kresten Lindorff-Larsen
- Linderstrøm-Lang Centre for Protein Science, Section for Biomolecular Sciences, Department of Biology, University for Copenhagen, Copenhagen, Denmark.
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8
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Abildgaard AB, Voutsinos V, Petersen SD, Larsen FB, Kampmeyer C, Johansson KE, Stein A, Ravid T, Andréasson C, Jensen MK, Lindorff-Larsen K, Hartmann-Petersen R. HSP70-binding motifs function as protein quality control degrons. Cell Mol Life Sci 2023; 80:32. [PMID: 36609589 PMCID: PMC11072582 DOI: 10.1007/s00018-022-04679-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Revised: 12/21/2022] [Accepted: 12/21/2022] [Indexed: 01/09/2023]
Abstract
Protein quality control (PQC) degrons are short protein segments that target misfolded proteins for proteasomal degradation, and thus protect cells against the accumulation of potentially toxic non-native proteins. Studies have shown that PQC degrons are hydrophobic and rarely contain negatively charged residues, features which are shared with chaperone-binding regions. Here we explore the notion that chaperone-binding regions may function as PQC degrons. When directly tested, we found that a canonical Hsp70-binding motif (the APPY peptide) functioned as a dose-dependent PQC degron both in yeast and in human cells. In yeast, Hsp70, Hsp110, Fes1, and the E3 Ubr1 target the APPY degron. Screening revealed that the sequence space within the chaperone-binding region of APPY that is compatible with degron function is vast. We find that the number of exposed Hsp70-binding sites in the yeast proteome correlates with a reduced protein abundance and half-life. Our results suggest that when protein folding fails, chaperone-binding sites may operate as PQC degrons, and that the sequence properties leading to PQC-linked degradation therefore overlap with those of chaperone binding.
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Affiliation(s)
- Amanda B Abildgaard
- Department of Biology, The Linderstrøm-Lang Centre for Protein Science, University of Copenhagen, Copenhagen, Denmark
| | - Vasileios Voutsinos
- Department of Biology, The Linderstrøm-Lang Centre for Protein Science, University of Copenhagen, Copenhagen, Denmark
| | - Søren D Petersen
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Fia B Larsen
- Department of Biology, The Linderstrøm-Lang Centre for Protein Science, University of Copenhagen, Copenhagen, Denmark
| | - Caroline Kampmeyer
- Department of Biology, The Linderstrøm-Lang Centre for Protein Science, University of Copenhagen, Copenhagen, Denmark
| | - Kristoffer E Johansson
- Department of Biology, The Linderstrøm-Lang Centre for Protein Science, University of Copenhagen, Copenhagen, Denmark
| | - Amelie Stein
- Department of Biology, The Linderstrøm-Lang Centre for Protein Science, University of Copenhagen, Copenhagen, Denmark
| | - Tommer Ravid
- Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Claes Andréasson
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Michael K Jensen
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Kresten Lindorff-Larsen
- Department of Biology, The Linderstrøm-Lang Centre for Protein Science, University of Copenhagen, Copenhagen, Denmark.
| | - Rasmus Hartmann-Petersen
- Department of Biology, The Linderstrøm-Lang Centre for Protein Science, University of Copenhagen, Copenhagen, Denmark.
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9
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Phosphorylation of Thr9 Affects the Folding Landscape of the N-Terminal Segment of Human AGT Enhancing Protein Aggregation of Disease-Causing Mutants. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27248762. [PMID: 36557898 PMCID: PMC9786777 DOI: 10.3390/molecules27248762] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Revised: 12/07/2022] [Accepted: 12/08/2022] [Indexed: 12/14/2022]
Abstract
The mutations G170R and I244T are the most common disease cause in primary hyperoxaluria type I (PH1). These mutations cause the misfolding of the AGT protein in the minor allele AGT-LM that contains the P11L polymorphism, which may affect the folding of the N-terminal segment (NTT-AGT). The NTT-AGT is phosphorylated at T9, although the role of this event in PH1 is unknown. In this work, phosphorylation of T9 was mimicked by introducing the T9E mutation in the NTT-AGT peptide and the full-length protein. The NTT-AGT conformational landscape was studied by circular dichroism, NMR, and statistical mechanical methods. Functional and stability effects on the full-length AGT protein were characterized by spectroscopic methods. The T9E and P11L mutations together reshaped the conformational landscape of the isolated NTT-AGT peptide by stabilizing ordered conformations. In the context of the full-length AGT protein, the T9E mutation had no effect on the overall AGT function or conformation, but enhanced aggregation of the minor allele (LM) protein and synergized with the mutations G170R and I244T. Our findings indicate that phosphorylation of T9 may affect the conformation of the NTT-AGT and synergize with PH1-causing mutations to promote aggregation in a genotype-specific manner. Phosphorylation should be considered a novel regulatory mechanism in PH1 pathogenesis.
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10
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How phosphorylation impacts intrinsically disordered proteins and their function. Essays Biochem 2022; 66:901-913. [PMID: 36350035 PMCID: PMC9760426 DOI: 10.1042/ebc20220060] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Revised: 10/14/2022] [Accepted: 10/17/2022] [Indexed: 11/10/2022]
Abstract
Phosphorylation is the most common post-translational modification (PTM) in eukaryotes, occurring particularly frequently in intrinsically disordered proteins (IDPs). These proteins are highly flexible and dynamic by nature. Thus, it is intriguing that the addition of a single phosphoryl group to a disordered chain can impact its function so dramatically. Furthermore, as many IDPs carry multiple phosphorylation sites, the number of possible states increases, enabling larger complexities and novel mechanisms. Although a chemically simple and well-understood process, the impact of phosphorylation on the conformational ensemble and molecular function of IDPs, not to mention biological output, is highly complex and diverse. Since the discovery of the first phosphorylation site in proteins 75 years ago, we have come to a much better understanding of how this PTM works, but with the diversity of IDPs and their capacity for carrying multiple phosphoryl groups, the complexity grows. In this Essay, we highlight some of the basic effects of IDP phosphorylation, allowing it to serve as starting point when embarking on studies into this topic. We further describe how recent complex cases of multisite phosphorylation of IDPs have been instrumental in widening our view on the effect of protein phosphorylation. Finally, we put forward perspectives on the phosphorylation of IDPs, both in relation to disease and in context of other PTMs; areas where deep insight remains to be uncovered.
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11
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Koren I. The hidden (degron) truth behind the degradation of DHFR disease-associated variants. Structure 2022; 30:1219-1221. [PMID: 36055220 DOI: 10.1016/j.str.2022.08.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
In this issue of Structure, Kampmeyer et al. provide detailed mechanistic insights into how structural changes in disease-associated dihydrofolate reductase (DHFR) missense variants affect their cellular protein abundance and discuss implications for hereditary megaloblastic anemia disease.
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Affiliation(s)
- Itay Koren
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, 5290002, Israel.
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