1
|
Litberg TJ, Horowitz S. Roles of Nucleic Acids in Protein Folding, Aggregation, and Disease. ACS Chem Biol 2024; 19:809-823. [PMID: 38477936 PMCID: PMC11149768 DOI: 10.1021/acschembio.3c00695] [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] [Indexed: 03/14/2024]
Abstract
The role of nucleic acids in protein folding and aggregation is an area of continued research, with relevance to understanding both basic biological processes and disease. In this review, we provide an overview of the trajectory of research on both nucleic acids as chaperones and their roles in several protein misfolding diseases. We highlight key questions that remain on the biophysical and biochemical specifics of how nucleic acids have large effects on multiple proteins' folding and aggregation behavior and how this pertains to multiple protein misfolding diseases.
Collapse
Affiliation(s)
- Theodore J. Litberg
- Department of Chemistry & Biochemistry and The Knoebel Institute for Healthy Aging, University of Denver, Denver, CO, 80208, USA
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL, 60611, USA
- Center for Synthetic Biology, Northwestern University, Evanston, IL, 60208, USA
| | - Scott Horowitz
- Department of Chemistry & Biochemistry and The Knoebel Institute for Healthy Aging, University of Denver, Denver, CO, 80208, USA
| |
Collapse
|
2
|
Dirks T, Krewing M, Vogel K, Bandow JE. The cold atmospheric pressure plasma-generated species superoxide, singlet oxygen and atomic oxygen activate the molecular chaperone Hsp33. J R Soc Interface 2023; 20:20230300. [PMID: 37876273 PMCID: PMC10598452 DOI: 10.1098/rsif.2023.0300] [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: 05/24/2023] [Accepted: 09/26/2023] [Indexed: 10/26/2023] Open
Abstract
Cold atmospheric pressure plasmas are used for surface decontamination or disinfection, e.g. in clinical settings. Protein aggregation has been shown to significantly contribute to the antibacterial mechanisms of plasma. To investigate the potential role of the redox-activated zinc-binding chaperone Hsp33 in preventing protein aggregation and thus mediating plasma resistance, we compared the plasma sensitivity of wild-type E. coli to that of an hslO deletion mutant lacking Hsp33 as well as an over-producing strain. Over-production of Hsp33 increased plasma survival rates above wild-type levels. Hsp33 was previously shown to be activated by plasma in vitro. For the PlasmaDerm source applied in dermatology, reversible activation of Hsp33 was confirmed. Thiol oxidation and Hsp33 unfolding, both crucial for Hsp33 activation, occurred during plasma treatment. After prolonged plasma exposure, however, unspecific protein oxidation was detected, the ability of Hsp33 to bind zinc ions was decreased without direct modifications of the zinc-binding motif, and the protein was inactivated. To identify chemical species of potential relevance for plasma-induced Hsp33 activation, reactive oxygen species were tested for their ability to activate Hsp33 in vitro. Superoxide, singlet oxygen and potentially atomic oxygen activate Hsp33, while no evidence was found for activation by ozone, peroxynitrite or hydroxyl radicals.
Collapse
Affiliation(s)
- Tim Dirks
- Applied Microbiology, Faculty of Biology and Biotechnology, Ruhr University Bochum, Bochum, Germany
| | - Marco Krewing
- Applied Microbiology, Faculty of Biology and Biotechnology, Ruhr University Bochum, Bochum, Germany
| | - Katharina Vogel
- Applied Microbiology, Faculty of Biology and Biotechnology, Ruhr University Bochum, Bochum, Germany
| | - Julia E. Bandow
- Applied Microbiology, Faculty of Biology and Biotechnology, Ruhr University Bochum, Bochum, Germany
| |
Collapse
|
3
|
Ulrich K. Redox-regulated chaperones in cell stress responses. Biochem Soc Trans 2023:233014. [PMID: 37140269 DOI: 10.1042/bst20221304] [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: 01/30/2023] [Revised: 04/12/2023] [Accepted: 04/18/2023] [Indexed: 05/05/2023]
Abstract
Proteostasis and redox homeostasis are tightly interconnected and most protein quality control pathways are under direct redox regulation which allow cells to immediately respond to oxidative stress conditions. The activation of ATP-independent chaperones serves as a first line of defense to counteract oxidative unfolding and aggregation of proteins. Conserved cysteine residues evolved as redox-sensitive switches which upon reversible oxidation induce substantial conformational rearrangements and the formation of chaperone-active complexes. In addition to harnessing unfolding proteins, these chaperone holdases interact with ATP-dependent chaperone systems to facilitate client refolding and restoring proteostasis during stress recovery. This minireview gives an insight into highly orchestrated mechanisms regulating the stress-specific activation and inactivation of redox-regulated chaperones and their role in cell stress responses.
Collapse
Affiliation(s)
- Kathrin Ulrich
- Institute of Biochemistry, Cellular Biochemistry, University of Cologne, Zuelpicher Str. 47a, 50674 Cologne, Germany
| |
Collapse
|
4
|
HslO ameliorates arrested ΔrecA polA cell growth and reduces DNA damage and oxidative stress responses. Sci Rep 2022; 12:22182. [PMID: 36564489 PMCID: PMC9789031 DOI: 10.1038/s41598-022-26703-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Accepted: 12/19/2022] [Indexed: 12/24/2022] Open
Abstract
Chromosome damage combined with defective recombinase activity has been widely considered to render cells inviable, owing to deficient double-strand break repair. However, temperature-sensitive recAts polA cells grow well upon induction of DNA damage and supplementation with catalase at restrictive temperatures. These treatments reduce intracellular reactive oxygen species (ROS) levels, which suggests that recAts polA cells are susceptible to ROS, but not chronic chromosome damage. Therefore, we investigated whether polA cells can tolerate a complete lack of recombinase function. We introduced a ΔrecA allele in polA cells in the presence or absence of the hslO-encoding redox molecular chaperon Hsp33 expression plasmid. Induction of the hslO gene with IPTG resulted in increased cell viability in ΔrecA polA cells with the hslO expression plasmid. ΔrecA polA cells in the absence of the hslO expression plasmid showed rich medium sensitivity with increasing ROS levels. Adding catalase to the culture medium considerably rescued growth arrest and decreased ROS. These results suggest that hslO expression manages oxidative stress to an acceptable level in cells with oxidative damage and rescues cell growth. Overall, ROS may regulate several processes, from damage response to cell division, via ROS-sensitive cell metabolism.
Collapse
|
5
|
Molecular Effects of Elongation Factor Ts and Trigger Factor on the Unfolding and Aggregation of Elongation Factor Tu Induced by the Prokaryotic Molecular Chaperone Hsp33. BIOLOGY 2021; 10:biology10111171. [PMID: 34827164 PMCID: PMC8614738 DOI: 10.3390/biology10111171] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 11/10/2021] [Accepted: 11/11/2021] [Indexed: 12/13/2022]
Abstract
Simple Summary Proteins are versatile biological macromolecules involved in most biological processes. However, because of the highly labile nature of protein structures, protein quality control (PQC) to ensure proteostasis (i.e., protein homeostasis)is difficult. Therefore, proteins of a specialized class (i.e., molecular chaperones) are required that assist in proper folding and prevent aberrant folding of other proteins. Hsp33 was originally discovered as a holding chaperone that is overexpressed upon heat shock and activated by oxidation to prevent the misfolding of client proteins. Recently, an unfoldase/aggregase activity of Hsp33 was identified in its reduced state against a specific substrate, EF-Tu, which plays a key role in protein biosynthesis in cells. The present study demonstrates that EF-Tu unfolding/aggregation by Hsp33 can be accelerated by another molecular chaperone trigger factor. Given that the unfolded/aggregated EF-Tu is finally degraded by another chaperone, Lon protease, it is likely that a chaperone network dysregulating EF-Tu operates in heat shock to attenuate protein biosynthesis, which is harmful to cell survival under stressed conditions. Therefore, the apparently contradictory chaperone function (i.e., promotion of client misfolding) of Hsp33 can also be associated with the PQC processes to ensure proteostasis in cells. Abstract Hsp33, a prokaryotic redox-regulated holding chaperone, has been recently identified to be able to exhibit an unfoldase and aggregase activity against elongation factor Tu (EF-Tu) in its reduced state. In this study, we investigated the effect of elongation factor Ts (EF-Ts) and trigger factor (TF) on Hsp33-mediated EF-Tu unfolding and aggregation using gel filtration, light scattering, circular dichroism, and isothermal titration calorimetry. We found that EF-Tu unfolding and subsequent aggregation induced by Hsp33 were evident even in its complex state with EF-Ts, which enhanced EF-Tu stability. In addition, although TF alone had no substantial effect on the stability of EF-Tu, it markedly amplified the Hsp33-mediated EF-Tu unfolding and aggregation. Collectively, the present results constitute the first example of synergistic unfoldase/aggregase activity of molecular chaperones and suggest that the stability of EF-Tu is modulated by a sophisticated network of molecular chaperones to regulate protein biosynthesis in cells under stress conditions.
Collapse
|
6
|
Kamenik AS, Handle PH, Hofer F, Kahler U, Kraml J, Liedl KR. Polarizable and non-polarizable force fields: Protein folding, unfolding, and misfolding. J Chem Phys 2021; 153:185102. [PMID: 33187403 DOI: 10.1063/5.0022135] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Molecular dynamics simulations are an invaluable tool to characterize the dynamic motions of proteins in atomistic detail. However, the accuracy of models derived from simulations inevitably relies on the quality of the underlying force field. Here, we present an evaluation of current non-polarizable and polarizable force fields (AMBER ff14SB, CHARMM 36m, GROMOS 54A7, and Drude 2013) based on the long-standing biophysical challenge of protein folding. We quantify the thermodynamics and kinetics of the β-hairpin formation using Markov state models of the fast-folding mini-protein CLN025. Furthermore, we study the (partial) folding dynamics of two more complex systems, a villin headpiece variant and a WW domain. Surprisingly, the polarizable force field in our set, Drude 2013, consistently leads to destabilization of the native state, regardless of the secondary structure element present. All non-polarizable force fields, on the other hand, stably characterize the native state ensembles in most cases even when starting from a partially unfolded conformation. Focusing on CLN025, we find that the conformational space captured with AMBER ff14SB and CHARMM 36m is comparable, but the ensembles from CHARMM 36m simulations are clearly shifted toward disordered conformations. While the AMBER ff14SB ensemble overstabilizes the native fold, CHARMM 36m and GROMOS 54A7 ensembles both agree remarkably well with experimental state populations. In addition, GROMOS 54A7 also reproduces experimental folding times most accurately. Our results further indicate an over-stabilization of helical structures with AMBER ff14SB. Nevertheless, the presented investigations strongly imply that reliable (un)folding dynamics of small proteins can be captured in feasible computational time with current additive force fields.
Collapse
Affiliation(s)
- Anna S Kamenik
- Institute of General, Inorganic and Theoretical Chemistry, University of Innsbruck, Innrain 80/82, A-6020 Innsbruck, Austria
| | - Philip H Handle
- Institute of General, Inorganic and Theoretical Chemistry, University of Innsbruck, Innrain 80/82, A-6020 Innsbruck, Austria
| | - Florian Hofer
- Institute of General, Inorganic and Theoretical Chemistry, University of Innsbruck, Innrain 80/82, A-6020 Innsbruck, Austria
| | - Ursula Kahler
- Institute of General, Inorganic and Theoretical Chemistry, University of Innsbruck, Innrain 80/82, A-6020 Innsbruck, Austria
| | - Johannes Kraml
- Institute of General, Inorganic and Theoretical Chemistry, University of Innsbruck, Innrain 80/82, A-6020 Innsbruck, Austria
| | - Klaus R Liedl
- Institute of General, Inorganic and Theoretical Chemistry, University of Innsbruck, Innrain 80/82, A-6020 Innsbruck, Austria
| |
Collapse
|
7
|
Qureshi R, Zhu M, Yan H. Visualization of Protein-Drug Interactions for the Analysis of Drug Resistance in Lung Cancer. IEEE J Biomed Health Inform 2021; 25:1839-1848. [PMID: 32991295 DOI: 10.1109/jbhi.2020.3027511] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Non-small cell lung cancer (NSCLC) caused by mutation of the epidermal growth factor receptor (EGFR) is a major cause of death worldwide. Tyrosine kinase inhibitors (TKIs) of EGFR have been developed and show promising results at the initial stage of therapy. However, in most cases, their efficacy becomes limited due to the emergence of secondary mutations causing drug resistance after about a year. In this work, we investigated the mechanism of drug resistance due to these mutations. We performed molecular dynamics (MD) simulations of EGFR-drug interactions to obtain Euclidean distance and binding free energy values to analyse drug resistance and visualize drug-protein interactions. A PCA-based method is proposed to find normal, rigid, flexible, and critical residues. We have established a systematic method for the visualization of protein-drug interactions, which provides an effective framework for the analysis of drug resistance in lung cancer at the atomic level.
Collapse
|
8
|
Dupuy E, Collet JF. Fort CnoX: Protecting Bacterial Proteins From Misfolding and Oxidative Damage. Front Mol Biosci 2021; 8:681932. [PMID: 34017858 PMCID: PMC8129009 DOI: 10.3389/fmolb.2021.681932] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Accepted: 04/13/2021] [Indexed: 11/13/2022] Open
Abstract
How proteins fold and are protected from stress-induced aggregation is a long-standing mystery and a crucial question in biology. Here, we present the current knowledge on the chaperedoxin CnoX, a novel type of protein folding factor that combines holdase chaperone activity with a redox protective function. Focusing on Escherichia coli CnoX, we explain the essential role played by this protein under HOCl (bleach) stress, discussing how it protects its substrates from both aggregation and irreversible oxidation, which could otherwise interfere with refolding. Finally, we highlight the unique ability of CnoX, apparently conserved during evolution, to cooperate with the GroEL/ES folding machinery.
Collapse
Affiliation(s)
- Emile Dupuy
- WELBIO, Brussels, Belgium.,de Duve Institute, Université catholique de Louvain, Brussels, Belgium
| | - Jean-François Collet
- WELBIO, Brussels, Belgium.,de Duve Institute, Université catholique de Louvain, Brussels, Belgium
| |
Collapse
|
9
|
Radzinski M, Oppenheim T, Metanis N, Reichmann D. The Cys Sense: Thiol Redox Switches Mediate Life Cycles of Cellular Proteins. Biomolecules 2021; 11:469. [PMID: 33809923 PMCID: PMC8004198 DOI: 10.3390/biom11030469] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2020] [Revised: 03/15/2021] [Accepted: 03/16/2021] [Indexed: 12/14/2022] Open
Abstract
Protein homeostasis is an essential component of proper cellular function; however, sustaining protein health is a challenging task, especially during the aerobic lifestyle. Natural cellular oxidants may be involved in cell signaling and antibacterial defense; however, imbalanced levels can lead to protein misfolding, cell damage, and death. This merges together the processes of protein homeostasis and redox regulation. At the heart of this process are redox-regulated proteins or thiol-based switches, which carefully mediate various steps of protein homeostasis across folding, localization, quality control, and degradation pathways. In this review, we discuss the "redox code" of the proteostasis network, which shapes protein health during cell growth and aging. We describe the sources and types of thiol modifications and elaborate on diverse strategies of evolving antioxidant proteins in proteostasis networks during oxidative stress conditions. We also highlight the involvement of cysteines in protein degradation across varying levels, showcasing the importance of cysteine thiols in proteostasis at large. The individual examples and mechanisms raised open the door for extensive future research exploring the interplay between the redox and protein homeostasis systems. Understanding this interplay will enable us to re-write the redox code of cells and use it for biotechnological and therapeutic purposes.
Collapse
Affiliation(s)
- Meytal Radzinski
- Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, Safra Campus Givat Ram, The Hebrew University of Jerusalem, Jerusalem 91904, Israel; (M.R.); (T.O.)
| | - Tal Oppenheim
- Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, Safra Campus Givat Ram, The Hebrew University of Jerusalem, Jerusalem 91904, Israel; (M.R.); (T.O.)
| | - Norman Metanis
- Institute of Chemistry, Safra Campus Givat Ram, The Hebrew University of Jerusalem, Jerusalem 91904, Israel;
| | - Dana Reichmann
- Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, Safra Campus Givat Ram, The Hebrew University of Jerusalem, Jerusalem 91904, Israel; (M.R.); (T.O.)
| |
Collapse
|
10
|
Ulrich K, Schwappach B, Jakob U. Thiol-based switching mechanisms of stress-sensing chaperones. Biol Chem 2020; 402:239-252. [PMID: 32990643 DOI: 10.1515/hsz-2020-0262] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2020] [Accepted: 09/11/2020] [Indexed: 12/13/2022]
Abstract
Thiol-based redox switches evolved as efficient post-translational regulatory mechanisms that enable individual proteins to rapidly respond to sudden environmental changes. While some protein functions need to be switched off to save resources and avoid potentially error-prone processes, protective functions become essential and need to be switched on. In this review, we focus on thiol-based activation mechanisms of stress-sensing chaperones. Upon stress exposure, these chaperones convert into high affinity binding platforms for unfolding proteins and protect cells against the accumulation of potentially toxic protein aggregates. Their chaperone activity is independent of ATP, a feature that becomes especially important under oxidative stress conditions, where cellular ATP levels drop and canonical ATP-dependent chaperones no longer operate. Vice versa, reductive inactivation and substrate release require the restoration of ATP levels, which ensures refolding of client proteins by ATP-dependent foldases. We will give an overview over the different strategies that cells evolved to rapidly increase the pool of ATP-independent chaperones upon oxidative stress and provide mechanistic insights into how stress conditions are used to convert abundant cellular proteins into ATP-independent holding chaperones.
Collapse
Affiliation(s)
- Kathrin Ulrich
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, 1105 N. University Ave., Ann Arbor, MI48109, USA
| | - Blanche Schwappach
- Department of Molecular Biology, Universitätsmedizin Göttingen, Humboldtallee 23, 37073 Göttingen, Germany
| | - Ursula Jakob
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, 1105 N. University Ave., Ann Arbor, MI48109, USA.,Department of Biological Chemistry, University of Michigan, Ann Arbor, MI48109, USA
| |
Collapse
|
11
|
Abstract
M. tuberculosis infections are responsible for more than 1 million deaths per year. Developing effective strategies to combat this disease requires a greater understanding of M. tuberculosis biology. As in all cells, protein quality control is essential for the viability of M. tuberculosis, which likely faces proteotoxic stress within a host. Here, we identify an M. tuberculosis protein, Ruc, that gains chaperone activity upon oxidation. Ruc represents a previously unrecognized family of redox-regulated chaperones found throughout the bacterial superkingdom. Additionally, we found that oxidized Ruc promotes the protein-folding activity of the essential M. tuberculosis Hsp70 chaperone system. This work contributes to a growing body of evidence that oxidative stress provides a particular strain on cellular protein stability. The bacterial pathogen Mycobacterium tuberculosis is the leading cause of death by an infectious disease among humans. Here, we describe a previously uncharacterized M. tuberculosis protein, Rv0991c, as a molecular chaperone that is activated by oxidation. Rv0991c has homologs in most bacterial lineages and appears to function analogously to the well-characterized Escherichia coli redox-regulated chaperone Hsp33, despite a dissimilar protein sequence. Rv0991c is transcriptionally coregulated with hsp60 and hsp70 chaperone genes in M. tuberculosis, suggesting that Rv0991c functions with these chaperones in maintaining protein quality control. Supporting this hypothesis, we found that, like oxidized Hsp33, oxidized Rv0991c prevents the aggregation of a model unfolded protein in vitro and promotes its refolding by the M. tuberculosis Hsp70 chaperone system. Furthermore, Rv0991c interacts with DnaK and can associate with many other M. tuberculosis proteins. We therefore propose that Rv0991c, which we named “Ruc” (redox-regulated protein with unstructured C terminus), represents a founding member of a new chaperone family that protects M. tuberculosis and other species from proteotoxicity during oxidative stress.
Collapse
|
12
|
Aramin S, Fassler R, Chikne V, Goldenberg M, Arian T, Kolet Eliaz L, Rimon O, Ram O, Michaeli S, Reichmann D. TrypOx, a Novel Eukaryotic Homolog of the Redox-Regulated Chaperone Hsp33 in Trypanosoma brucei. Front Microbiol 2020; 11:1844. [PMID: 32849441 PMCID: PMC7423844 DOI: 10.3389/fmicb.2020.01844] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Accepted: 07/14/2020] [Indexed: 01/28/2023] Open
Abstract
ATP-independent chaperones are widespread across all domains of life and serve as the first line of defense during protein unfolding stresses. One of the known crucial chaperones for bacterial survival in a hostile environment (e.g., heat and oxidative stress) is the highly conserved, redox-regulated ATP-independent bacterial chaperone Hsp33. Using a bioinformatic analysis, we describe novel eukaryotic homologs of Hsp33 identified in eukaryotic pathogens belonging to the kinetoplastids, a family responsible for lethal human diseases such as Chagas disease as caused by Trypanosoma cruzi, African sleeping sickness caused by Trypanosoma brucei spp., and leishmaniasis pathologies delivered by various Leishmania species. During their pathogenic life cycle, kinetoplastids need to cope with elevated temperatures and oxidative stress, the same conditions which convert Hsp33 into a powerful chaperone in bacteria, thus preventing aggregation of a wide range of misfolded proteins. Here, we focused on a functional characterization of the Hsp33 homolog in one of the members of the kinetoplastid family, T. brucei, (Tb927.6.2630), which we have named TrypOx. RNAi silencing of TrypOx led to a significant decrease in the survival of T. brucei under mild oxidative stress conditions, implying a protective role of TrypOx during the Trypanosomes growth. We then adopted a proteomics-driven approach to investigate the role of TrypOx in defining the oxidative stress response. Depletion of TrypOx significantly altered the abundance of proteins mediating redox homeostasis, linking TrypOx with the antioxidant system. Using biochemical approaches, we identified the redox-switch domain of TrypOx, showing its modularity and oxidation-dependent structural plasticity. Kinetoplastid parasites such as T. brucei need to cope with high levels of oxidants produced by the innate immune system, such that parasite-specific antioxidant proteins like TrypOx - which are depleted in mammals - are highly promising candidates for drug targeting.
Collapse
Affiliation(s)
- Samar Aramin
- Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, Safra Campus Givat Ram, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Rosi Fassler
- Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, Safra Campus Givat Ram, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Vaibhav Chikne
- The Mina and Everard Goodman Faculty of Life Sciences, Advanced Materials and Nanotechnology Institute, Bar-Ilan University, Ramat Gan, Israel
| | - Mor Goldenberg
- Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, Safra Campus Givat Ram, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Tal Arian
- Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, Safra Campus Givat Ram, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Liat Kolet Eliaz
- The Mina and Everard Goodman Faculty of Life Sciences, Advanced Materials and Nanotechnology Institute, Bar-Ilan University, Ramat Gan, Israel
| | - Oded Rimon
- Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, Safra Campus Givat Ram, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Oren Ram
- Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, Safra Campus Givat Ram, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Shulamit Michaeli
- The Mina and Everard Goodman Faculty of Life Sciences, Advanced Materials and Nanotechnology Institute, Bar-Ilan University, Ramat Gan, Israel
| | - Dana Reichmann
- Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, Safra Campus Givat Ram, The Hebrew University of Jerusalem, Jerusalem, Israel
| |
Collapse
|
13
|
Nava Ramírez T, Hansberg W. Características comunes de las chaperonas pequeñas y diméricas. TIP REVISTA ESPECIALIZADA EN CIENCIAS QUÍMICO-BIOLÓGICAS 2020. [DOI: 10.22201/fesz.23958723e.2020.0.234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Las chaperonas moleculares constituyen un mecanismo importante para evitar la muerte celular provocada por la agregación de proteínas. Las chaperonas independientes del ATP son un grupo de proteínas de bajo peso molecular que pueden proteger y ayudar a alcanzar la estructura nativa de las proteínas desplegadas o mal plegadas sin necesidad de un gasto energético. Hemos encontrado que el dominio C-terminal de las catalasas de subunidad grande tiene actividad de chaperona. Por ello, en esta revisión analizamos las características más comunes de las chaperonas pequeñas y más estudiadas como: αB-cristalina, Hsp20, Spy, Hsp33 y Hsp31. En particular, se examina la participación de los aminoácidos hidrofóbicos y de los aminoácidos con carga en el reconocimiento de las proteínas sustrato, así como el papel que tiene la forma dimérica y su oligomerización en la actividad de chaperona. En cada una de esas chaperonas revisaremos la estructura de la proteína, su función, localización celular e importancia para la célula.
Collapse
|
14
|
Hu Y, Li C, He L, Jin C, Liu M. Mechanisms of Chaperones as Active Assistant/Protector for Proteins: Insights from NMR Studies. CHINESE J CHEM 2020. [DOI: 10.1002/cjoc.201900441] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Yunfei Hu
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan National Laboratory for OptoelectronicsNational Center for Magnetic Resonance in Wuhan, Key Laboratory of Magnetic Resonance in Biological Systems, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences (CAS) Wuhan Hubei 430071 China
- University of Chinese Academy of Sciences Beijing 100049 China
| | - Conggang Li
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan National Laboratory for OptoelectronicsNational Center for Magnetic Resonance in Wuhan, Key Laboratory of Magnetic Resonance in Biological Systems, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences (CAS) Wuhan Hubei 430071 China
- University of Chinese Academy of Sciences Beijing 100049 China
| | - Lichun He
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan National Laboratory for OptoelectronicsNational Center for Magnetic Resonance in Wuhan, Key Laboratory of Magnetic Resonance in Biological Systems, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences (CAS) Wuhan Hubei 430071 China
- University of Chinese Academy of Sciences Beijing 100049 China
| | - Changwen Jin
- Beijing Nuclear Magnetic Resonance Center, College of Chemistry and Molecular Engineering, College of Life Sciences, Peking University Beijing 100871 China
| | - Maili Liu
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan National Laboratory for OptoelectronicsNational Center for Magnetic Resonance in Wuhan, Key Laboratory of Magnetic Resonance in Biological Systems, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences (CAS) Wuhan Hubei 430071 China
- University of Chinese Academy of Sciences Beijing 100049 China
| |
Collapse
|
15
|
Moayed F, Bezrukavnikov S, Naqvi MM, Groitl B, Cremers CM, Kramer G, Ghosh K, Jakob U, Tans SJ. The Anti-Aggregation Holdase Hsp33 Promotes the Formation of Folded Protein Structures. Biophys J 2019; 118:85-95. [PMID: 31757359 DOI: 10.1016/j.bpj.2019.10.040] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Revised: 10/04/2019] [Accepted: 10/15/2019] [Indexed: 11/26/2022] Open
Abstract
Holdase chaperones are known to be central to suppressing aggregation, but how they affect substrate conformations remains poorly understood. Here, we use optical tweezers to study how the holdase Hsp33 alters folding transitions within single maltose binding proteins and aggregation transitions between maltose binding protein substrates. Surprisingly, we find that Hsp33 not only suppresses aggregation but also guides the folding process. Two modes of action underlie these effects. First, Hsp33 binds unfolded chains, which suppresses aggregation between substrates and folding transitions within substrates. Second, Hsp33 binding promotes substrate states in which most of the chain is folded and modifies their structure, possibly by intercalating its intrinsically disordered regions. A statistical ensemble model shows how Hsp33 function results from the competition between these two contrasting effects. Our findings reveal an unexpectedly comprehensive functional repertoire for Hsp33 that may be more prevalent among holdases and dispels the notion of a strict chaperone hierarchy.
Collapse
Affiliation(s)
| | | | | | - Bastian Groitl
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, Michigan
| | - Claudia M Cremers
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, Michigan
| | - Guenter Kramer
- Center for Molecular Biology of the University of Heidelberg (ZMBH), DKFZ-ZMBH Alliance, Heidelberg, Germany
| | - Kingshuk Ghosh
- Department of Physics and Astronomy, University of Denver, Denver, Colorado
| | - Ursula Jakob
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, Michigan
| | | |
Collapse
|
16
|
Wu K, Stull F, Lee C, Bardwell JCA. Protein folding while chaperone bound is dependent on weak interactions. Nat Commun 2019; 10:4833. [PMID: 31645566 PMCID: PMC6811625 DOI: 10.1038/s41467-019-12774-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Accepted: 09/23/2019] [Indexed: 12/31/2022] Open
Abstract
It is generally assumed that protein clients fold following their release from chaperones instead of folding while remaining chaperone-bound, in part because binding is assumed to constrain the mobility of bound clients. Previously, we made the surprising observation that the ATP-independent chaperone Spy allows its client protein Im7 to fold into the native state while continuously bound to the chaperone. Spy apparently permits sufficient client mobility to allow folding to occur while chaperone bound. Here, we show that strengthening the interaction between Spy and a recently discovered client SH3 strongly inhibits the ability of the client to fold while chaperone bound. The more tightly Spy binds to its client, the more it slows the folding rate of the bound client. Efficient chaperone-mediated folding while bound appears to represent an evolutionary balance between interactions of sufficient strength to mediate folding and interactions that are too tight, which tend to inhibit folding. Spy is an ATP independent chaperone that allows folding of its client protein Im7 while continuously bound to Spy. Here the authors employ kinetics measurements to study the folding of another Spy client protein SH3 and find that Spy’s ability to allow a client to fold while bound is inversely related to how strongly it interacts with that client.
Collapse
Affiliation(s)
- Kevin Wu
- Howard Hughes Medical Institute, University of Michigan, Ann Arbor, MI, 48109-1085, USA.,Department of Biophysics, University of Michigan, Ann Arbor, MI, 48109-1055, USA
| | - Frederick Stull
- Howard Hughes Medical Institute, University of Michigan, Ann Arbor, MI, 48109-1085, USA.,Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI, 48109-1085, USA.,Department of Chemistry, Western Michigan University, Kalamazoo, MI, 49008-5413, USA
| | - Changhan Lee
- Howard Hughes Medical Institute, University of Michigan, Ann Arbor, MI, 48109-1085, USA.,Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI, 48109-1085, USA
| | - James C A Bardwell
- Howard Hughes Medical Institute, University of Michigan, Ann Arbor, MI, 48109-1085, USA. .,Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI, 48109-1085, USA.
| |
Collapse
|
17
|
Goemans CV, Collet JF. Stress-induced chaperones: a first line of defense against the powerful oxidant hypochlorous acid. F1000Res 2019; 8. [PMID: 31583082 PMCID: PMC6758839 DOI: 10.12688/f1000research.19517.1] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 09/18/2019] [Indexed: 01/12/2023] Open
Abstract
Hypochlorous acid (HOCl; bleach) is a powerful weapon used by our immune system to eliminate invading bacteria. Yet the way HOCl actually kills bacteria and how they defend themselves from its oxidative action have only started to be uncovered. As this molecule induces both protein oxidation and aggregation, bacteria need concerted efforts of chaperones and antioxidants to maintain proteostasis during stress. Recent advances in the field identified several stress-activated chaperones, like Hsp33, RidA, and CnoX, which display unique structural features and play a central role in protecting the bacterial proteome during HOCl stress.
Collapse
Affiliation(s)
- Camille V Goemans
- European Molecular Biology Laboratory, Meyerhofstrasse 1, 69117, Heidelberg, Germany
| | | |
Collapse
|
18
|
Casanova-Morales N, Quiroga-Roger D, Alfaro-Valdés HM, Alavi Z, Lagos-Espinoza MIA, Zocchi G, Wilson CAM. Mechanical properties of BiP protein determined by nano-rheology. Protein Sci 2019; 27:1418-1426. [PMID: 29696702 DOI: 10.1002/pro.3432] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2017] [Revised: 04/06/2018] [Accepted: 04/19/2018] [Indexed: 02/01/2023]
Abstract
Immunoglobulin Binding Protein (BiP) is a chaperone and molecular motor belonging to the Hsp70 family, involved in the regulation of important biological processes such as synthesis, folding and translocation of proteins in the Endoplasmic Reticulum. BiP has two highly conserved domains: the N-terminal Nucleotide-Binding Domain (NBD), and the C-terminal Substrate-Binding Domain (SBD), connected by a hydrophobic linker. ATP binds and it is hydrolyzed to ADP in the NBD, and BiP's extended polypeptide substrates bind in the SBD. Like many molecular motors, BiP function depends on both structural and catalytic properties that may contribute to its performance. One novel approach to study the mechanical properties of BiP considers exploring the changes in the viscoelastic behavior upon ligand binding, using a technique called nano-rheology. This technique is essentially a traditional rheology experiment, in which an oscillatory force is directly applied to the protein under study, and the resulting average deformation is measured. Our results show that the folded state of the protein behaves like a viscoelastic material, getting softer when it binds nucleotides- ATP, ADP, and AMP-PNP-, but stiffer when binding HTFPAVL peptide substrate. Also, we observed that peptide binding dramatically increases the affinity for ADP, decreasing it dissociation constant (KD ) around 1000 times, demonstrating allosteric coupling between SBD and NBD domains.
Collapse
Affiliation(s)
- Nathalie Casanova-Morales
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Santiago, 8380494, Chile
| | - Diego Quiroga-Roger
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Santiago, 8380494, Chile
| | - Hilda M Alfaro-Valdés
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Santiago, 8380494, Chile
| | - Zahra Alavi
- Department of Physics and Astronomy, University of California - Los Angeles, Los Angeles, California, 90095, US.,Department of Physics, Loyola Marymount University, Los Angeles, California, 90045, US
| | - Miguel I A Lagos-Espinoza
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Santiago, 8380494, Chile
| | - Giovanni Zocchi
- Department of Physics and Astronomy, University of California - Los Angeles, Los Angeles, California, 90095, US
| | - Christian A M Wilson
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Santiago, 8380494, Chile
| |
Collapse
|
19
|
Local unfolding of the HSP27 monomer regulates chaperone activity. Nat Commun 2019; 10:1068. [PMID: 30842409 PMCID: PMC6403371 DOI: 10.1038/s41467-019-08557-8] [Citation(s) in RCA: 77] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Accepted: 12/20/2018] [Indexed: 12/21/2022] Open
Abstract
The small heat-shock protein HSP27 is a redox-sensitive molecular chaperone that is expressed throughout the human body. Here, we describe redox-induced changes to the structure, dynamics, and function of HSP27 and its conserved α-crystallin domain (ACD). While HSP27 assembles into oligomers, we show that the monomers formed upon reduction are highly active chaperones in vitro, but are susceptible to self-aggregation. By using relaxation dispersion and high-pressure nuclear magnetic resonance (NMR) spectroscopy, we observe that the pair of β-strands that mediate dimerisation partially unfold in the monomer. We note that numerous HSP27 mutations associated with inherited neuropathies cluster to this dynamic region. High levels of sequence conservation in ACDs from mammalian sHSPs suggest that the exposed, disordered interface present in free monomers or oligomeric subunits may be a general, functional feature of sHSPs. The small heat-shock protein HSP27 occurs predominantly in oligomeric forms, which makes its structural characterisation challenging. Here the authors employ CPMG and high-pressure NMR with native mass spectrometry and biophysical assays to show that the active monomeric form of HSP27 is substantially disordered and highly chaperone-active.
Collapse
|
20
|
Unique Unfoldase/Aggregase Activity of a Molecular Chaperone Hsp33 in its Holding-Inactive State. J Mol Biol 2019; 431:1468-1480. [DOI: 10.1016/j.jmb.2019.02.022] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Revised: 02/12/2019] [Accepted: 02/18/2019] [Indexed: 11/21/2022]
|
21
|
Teixeira F, Tse E, Castro H, Makepeace KAT, Meinen BA, Borchers CH, Poole LB, Bardwell JC, Tomás AM, Southworth DR, Jakob U. Chaperone activation and client binding of a 2-cysteine peroxiredoxin. Nat Commun 2019; 10:659. [PMID: 30737390 PMCID: PMC6368585 DOI: 10.1038/s41467-019-08565-8] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2018] [Accepted: 01/14/2019] [Indexed: 02/02/2023] Open
Abstract
Many 2-Cys-peroxiredoxins (2-Cys-Prxs) are dual-function proteins, either acting as peroxidases under non-stress conditions or as chaperones during stress. The mechanism by which 2-Cys-Prxs switch functions remains to be defined. Our work focuses on Leishmania infantum mitochondrial 2-Cys-Prx, whose reduced, decameric subpopulation adopts chaperone function during heat shock, an activity that facilitates the transition from insects to warm-blooded host environments. Here, we have solved the cryo-EM structure of mTXNPx in complex with a thermally unfolded client protein, and revealed that the flexible N-termini of mTXNPx form a well-resolved central belt that contacts and encapsulates the unstructured client protein in the center of the decamer ring. In vivo and in vitro cross-linking studies provide further support for these interactions, and demonstrate that mTXNPx decamers undergo temperature-dependent structural rearrangements specifically at the dimer-dimer interfaces. These structural changes appear crucial for exposing chaperone-client binding sites that are buried in the peroxidase-active protein.
Collapse
Affiliation(s)
- Filipa Teixeira
- Department of Molecular, Cellular and Developmental, University of Michigan, Ann Arbor, 48109-1085, MI, USA.,i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, 4200-135, Portugal.,IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, 4050-313, Portugal.,ICBAS - Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Porto, 4050-313, Portugal
| | - Eric Tse
- Department of Biochemistry and Biophysics, Institute for Neurodegenerative Diseases, University of California, San Francisco, 94158, CA, USA
| | - Helena Castro
- i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, 4200-135, Portugal.,IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, 4050-313, Portugal
| | - Karl A T Makepeace
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, V8P 5C2, BC, Canada.,Genome British Columbia Proteomics Centre, University of Victoria, Victoria, V8Z 7X8, BC, Canada
| | - Ben A Meinen
- Department of Molecular, Cellular and Developmental, University of Michigan, Ann Arbor, 48109-1085, MI, USA.,Howard Hughes Medical Institute, Ann Arbor, 48109-1085, MI, USA
| | - Christoph H Borchers
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, V8P 5C2, BC, Canada.,Genome British Columbia Proteomics Centre, University of Victoria, Victoria, V8Z 7X8, BC, Canada.,Gerald Bronfman Department of Oncology, Jewish General Hospital, Montreal, H4A 3T2, QC, Canada.,Proteomics Centre, Segal Cancer Centre, Lady Davis Institute, Jewish General Hospital, Montreal, H3T 1E2, QC, Canada
| | - Leslie B Poole
- Department of Biochemistry, Wake Forest School of Medicine, Winston-Salem, 27157, NC, USA
| | - James C Bardwell
- Department of Molecular, Cellular and Developmental, University of Michigan, Ann Arbor, 48109-1085, MI, USA.,Howard Hughes Medical Institute, Ann Arbor, 48109-1085, MI, USA
| | - Ana M Tomás
- i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, 4200-135, Portugal.,IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, 4050-313, Portugal.,ICBAS - Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Porto, 4050-313, Portugal
| | - Daniel R Southworth
- Department of Biochemistry and Biophysics, Institute for Neurodegenerative Diseases, University of California, San Francisco, 94158, CA, USA.
| | - Ursula Jakob
- Department of Molecular, Cellular and Developmental, University of Michigan, Ann Arbor, 48109-1085, MI, USA.
| |
Collapse
|
22
|
Erdős G, Mészáros B, Reichmann D, Dosztányi Z. Large-Scale Analysis of Redox-Sensitive Conditionally Disordered Protein Regions Reveals Their Widespread Nature and Key Roles in High-Level Eukaryotic Processes. Proteomics 2019; 19:e1800070. [PMID: 30628183 DOI: 10.1002/pmic.201800070] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2018] [Revised: 12/13/2018] [Indexed: 12/17/2022]
Abstract
Recently developed quantitative redox proteomic studies enable the direct identification of redox-sensing cysteine residues that regulate the functional behavior of target proteins in response to changing levels of reactive oxygen species. At the molecular level, redox regulation can directly modify the active sites of enzymes, although a growing number of examples indicate the importance of an additional underlying mechanism that involves conditionally disordered proteins. These proteins alter their functional behavior by undergoing a disorder-to-order transition in response to changing redox conditions. However, the extent to which this mechanism is used in various proteomes is currently unknown. Here, a recently developed sequence-based prediction tool incorporated into the IUPred2A web server is used to estimate redox-sensitive conditionally disordered regions at a large scale. It is shown that redox-sensitive conditional disorder is fairly widespread in various proteomes and that its presence strongly correlates with the expansion of specific domains in multicellular organisms that largely rely on extra stability provided by disulfide bonds or zinc ion binding. The analyses of yeast redox proteomes and human disease data further underlie the significance of this phenomenon in the regulation of a wide range of biological processes, as well as its biomedical importance.
Collapse
Affiliation(s)
- Gábor Erdős
- MTA-ELTE Lendület Bioinformatics Research Group, Department of Biochemistry, Eötvös Loránd University, Budapest, H-1117, Hungary
| | - Bálint Mészáros
- MTA-ELTE Lendület Bioinformatics Research Group, Department of Biochemistry, Eötvös Loránd University, Budapest, H-1117, Hungary.,Structural and Computational Biology Unit, European Molecular Biology Laboratory, Heidelberg, 69117, Germany
| | - Dana Reichmann
- Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, Safra Campus Givat Ram, The Hebrew University of Jerusalem, Jerusalem, 91904, Israel
| | - Zsuzsanna Dosztányi
- MTA-ELTE Lendület Bioinformatics Research Group, Department of Biochemistry, Eötvös Loránd University, Budapest, H-1117, Hungary
| |
Collapse
|
23
|
Reichmann D, Voth W, Jakob U. Maintaining a Healthy Proteome during Oxidative Stress. Mol Cell 2019; 69:203-213. [PMID: 29351842 DOI: 10.1016/j.molcel.2017.12.021] [Citation(s) in RCA: 111] [Impact Index Per Article: 22.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Revised: 12/11/2017] [Accepted: 12/21/2017] [Indexed: 12/11/2022]
Abstract
Some of the most challenging stress conditions that organisms encounter during their lifetime involve the transient accumulation of reactive oxygen and chlorine species. Extremely reactive to amino acid side chains, these oxidants cause widespread protein unfolding and aggregation. It is therefore not surprising that cells draw on a variety of different strategies to counteract the damage and maintain a healthy proteome. Orchestrated largely by direct changes in the thiol oxidation status of key proteins, the response strategies involve all layers of protein protection. Reprogramming of basic biological functions helps decrease nascent protein synthesis and restore redox homeostasis. Mobilization of oxidative stress-activated chaperones and production of stress-resistant non-proteinaceous chaperones prevent irreversible protein aggregation. Finally, redox-controlled increase in proteasome activity removes any irreversibly damaged proteins. Together, these systems pave the way to restore protein homeostasis and enable organisms to survive stress conditions that are inevitable when living an aerobic lifestyle.
Collapse
Affiliation(s)
- Dana Reichmann
- Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, Safra Campus Givat Ram, The Hebrew University of Jerusalem, Jerusalem 91904, Israel.
| | - Wilhelm Voth
- Department of Molecular, Cellular, and Developmental Biology and Department of Biological Chemistry, University of Michigan, Ann Arbor, MI 48109-1048, USA
| | - Ursula Jakob
- Department of Molecular, Cellular, and Developmental Biology and Department of Biological Chemistry, University of Michigan, Ann Arbor, MI 48109-1048, USA.
| |
Collapse
|
24
|
Xu Q, Shan Y, Wang N, Liu Y, Zhang M, Ma M. Sialic acid involves in the interaction between ovomucin and hemagglutinin and influences the antiviral activity of ovomucin. Int J Biol Macromol 2018; 119:533-539. [PMID: 30071221 PMCID: PMC7124660 DOI: 10.1016/j.ijbiomac.2018.07.186] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2018] [Revised: 07/23/2018] [Accepted: 07/29/2018] [Indexed: 11/27/2022]
Abstract
Ovomucin (OVM) plays an important role in inhibiting infection of various pathogens. However, this bioactivity mechanism is not much known. Here, the role of sialic acid in OVM anti-virus activity has been studied by ELISA with lectin or ligand. Structural changes of OVM after removing sialic acid were analyzed by circular dichroism and fluorescence spectroscopy. OVM could be binding to the hemagglutinin (HA) of avian influenza viruses H5N1 and H1N1, this binding was specific and required the involvement of sialic acid. When sialic acid was removed, the binding was significantly reduced 71.5% and 64.35%, respectively. Therefore, sialic acid was proved as a recognition site which avian influenza virus bound to. Meanwhile, the endogenous fluorescence and surface hydrophobicity of OVM removing sialic acid were increased and the secondary structure tended to shift to random coil. This indicated that OVM molecules were in an unfolded state and spatial conformation disorder raising weakly. Remarkably, free sialic acid strongly promoted OVM binding to HA and thereby enhanced the interaction. It may contribute to the inhibition of host cell infection, agglutinate viruses. This study can be extended to the deepening of passive immunization field.
Collapse
Affiliation(s)
- Qi Xu
- College of Food Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, People's Republic of China
| | - Yuanyuan Shan
- College of Food Science and Engineering, Northwest A&F University, Yangling 712100, People's Republic of China
| | - Ning Wang
- College of Food Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, People's Republic of China
| | - Yaping Liu
- College of Food Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, People's Republic of China
| | - Maojie Zhang
- College of Food Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, People's Republic of China
| | - Meihu Ma
- College of Food Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, People's Republic of China.
| |
Collapse
|
25
|
Fassler R, Edinger N, Rimon O, Reichmann D. Defining Hsp33's Redox-regulated Chaperone Activity and Mapping Conformational Changes on Hsp33 Using Hydrogen-deuterium Exchange Mass Spectrometry. J Vis Exp 2018. [PMID: 29939186 DOI: 10.3791/57806] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Living organisms regularly need to cope with fluctuating environments during their life cycle, including changes in temperature, pH, the accumulation of reactive oxygen species, and more. These fluctuations can lead to a widespread protein unfolding, aggregation, and cell death. Therefore, cells have evolved a dynamic and stress-specific network of molecular chaperones, which maintain a "healthy" proteome during stress conditions. ATP-independent chaperones constitute one major class of molecular chaperones, which serve as first-line defense molecules, protecting against protein aggregation in a stress-dependent manner. One feature these chaperones have in common is their ability to utilize structural plasticity for their stress-specific activation, recognition, and release of the misfolded client. In this paper, we focus on the functional and structural analysis of one such intrinsically disordered chaperone, the bacterial redox-regulated Hsp33, which protects proteins against aggregation during oxidative stress. Here, we present a toolbox of diverse techniques for studying redox-regulated chaperone activity, as well as for mapping conformational changes of the chaperone, underlying its activity. Specifically, we describe a workflow which includes the preparation of fully reduced and fully oxidized proteins, followed by an analysis of the chaperone anti-aggregation activity in vitro using light-scattering, focusing on the degree of the anti-aggregation activity and its kinetics. To overcome frequent outliers accumulated during aggregation assays, we describe the usage of Kfits, a novel graphical tool which allows easy processing of kinetic measurements. This tool can be easily applied to other types of kinetic measurements for removing outliers and fitting kinetic parameters. To correlate the function with the protein structure, we describe the setup and workflow of a structural mass spectrometry technique, hydrogen-deuterium exchange mass spectrometry, that allows the mapping of conformational changes on the chaperone and substrate during different stages of Hsp33 activity. The same methodology can be applied to other protein-protein and protein-ligand interactions.
Collapse
Affiliation(s)
- Rosi Fassler
- Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, Safra Campus Givat Ram, The Hebrew University of Jerusalem
| | - Nufar Edinger
- Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, Safra Campus Givat Ram, The Hebrew University of Jerusalem
| | - Oded Rimon
- Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, Safra Campus Givat Ram, The Hebrew University of Jerusalem
| | - Dana Reichmann
- Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, Safra Campus Givat Ram, The Hebrew University of Jerusalem;
| |
Collapse
|
26
|
A switch point in the molecular chaperone Hsp90 responding to client interaction. Nat Commun 2018; 9:1472. [PMID: 29662162 PMCID: PMC5902578 DOI: 10.1038/s41467-018-03946-x] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Accepted: 03/22/2018] [Indexed: 12/13/2022] Open
Abstract
Heat shock protein 90 (Hsp90) is a dimeric molecular chaperone that undergoes large conformational changes during its functional cycle. It has been established that conformational switch points exist in the N-terminal (Hsp90-N) and C-terminal (Hsp90-C) domains of Hsp90, however information for switch points in the large middle-domain (Hsp90-M) is scarce. Here we report on a tryptophan residue in Hsp90-M as a new type of switch point. Our study shows that this conserved tryptophan senses the interaction of Hsp90 with a stringent client protein and transfers this information via a cation–π interaction with a neighboring lysine. Mutations at this position hamper the communication between domains and the ability of a client protein to affect the Hsp90 cycle. The residue thus allows Hsp90 to transmit information on the binding of a client from Hsp90-M to Hsp90-N which is important for progression of the conformational cycle and the efficient processing of client proteins. The heat shock protein 90 (Hsp90) chaperone undergoes large conformational changes during its functional cycle. Here the authors combine in vivo, biochemical, biophysical and computational approaches and provide insights into the allosteric regulation of Hsp90 by identifying and characterizing a switch point in the Hsp90 middle domain.
Collapse
|
27
|
Davis CM, Gruebele M, Sukenik S. How does solvation in the cell affect protein folding and binding? Curr Opin Struct Biol 2018; 48:23-29. [PMID: 29035742 DOI: 10.1016/j.sbi.2017.09.003] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Revised: 09/19/2017] [Accepted: 09/22/2017] [Indexed: 12/21/2022]
Abstract
The cellular environment is highly diverse and capable of rapid changes in solute composition and concentrations. Decades of protein studies have highlighted their sensitivity to solute environment, yet these studies were rarely performed in situ. Recently, new techniques capable of monitoring proteins in their natural context within a live cell have emerged. A recurring theme of these investigations is the importance of the often-neglected cellular solvation environment to protein function. An emerging consensus is that protein processes in the cell are affected by a combination of steric and non-steric interactions with this solution. Here we explain how protein surface area and volume changes control these two interaction types, and give recent examples that highlight how even mild environmental changes can alter cellular processes.
Collapse
Affiliation(s)
- Caitlin M Davis
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Department of Physics, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Martin Gruebele
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Department of Physics, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
| | - Shahar Sukenik
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| |
Collapse
|
28
|
Rimon O, Suss O, Goldenberg M, Fassler R, Yogev O, Amartely H, Propper G, Friedler A, Reichmann D. A Role of Metastable Regions and Their Connectivity in the Inactivation of a Redox-Regulated Chaperone and Its Inter-Chaperone Crosstalk. Antioxid Redox Signal 2017; 27:1252-1267. [PMID: 28394178 DOI: 10.1089/ars.2016.6900] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
AIMS A recently discovered group of conditionally disordered chaperones share a very unique feature; they need to lose structure to become active as chaperones. This activation mechanism makes these chaperones particularly suited to respond to protein-unfolding stress conditions, such as oxidative unfolding. However, the role of this disorder in stress-related activation, chaperone function, and the crosstalk with other chaperone systems is not yet clear. Here, we focus on one of the members of the conditionally disordered chaperones, a thiol-redox switch of the bacterial proteostasis system, Hsp33. RESULTS By modifying the Hsp33's sequence, we reveal that the metastable region has evolved to abolish redox-dependent chaperone activity, rather than enhance binding affinity for client proteins. The intrinsically disordered region of Hsp33 serves as an anchor for the reduced, inactive state of Hsp33, and it dramatically affects the crosstalk with the synergetic chaperone system, DnaK/J. Using mass spectrometry, we describe the role that the metastable region plays in determining client specificity during normal and oxidative stress conditions in the cell. Innovation and Conclusion: We uncover a new role of protein plasticity in Hsp33's inactivation, client specificity, crosstalk with the synergistic chaperone system DnaK/J, and oxidative stress-specific interactions in bacteria. Our results also suggest that Hsp33 might serve as a member of the house-keeping proteostasis machinery, tasked with maintaining a "healthy" proteome during normal conditions, and that this function does not depend on the metastable linker region. Antioxid. Redox Signal. 27, 1252-1267.
Collapse
Affiliation(s)
- Oded Rimon
- 1 Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, Safra Campus Givat Ram, The Hebrew University of Jerusalem , Jerusalem, Israel
| | - Ohad Suss
- 1 Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, Safra Campus Givat Ram, The Hebrew University of Jerusalem , Jerusalem, Israel
| | - Mor Goldenberg
- 1 Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, Safra Campus Givat Ram, The Hebrew University of Jerusalem , Jerusalem, Israel
| | - Rosi Fassler
- 1 Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, Safra Campus Givat Ram, The Hebrew University of Jerusalem , Jerusalem, Israel
| | - Ohad Yogev
- 1 Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, Safra Campus Givat Ram, The Hebrew University of Jerusalem , Jerusalem, Israel
| | - Hadar Amartely
- 2 Institute of Chemistry, The Hebrew University of Jerusalem , Safra Campus Givat Ram, Jerusalem, Israel
| | - Guy Propper
- 1 Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, Safra Campus Givat Ram, The Hebrew University of Jerusalem , Jerusalem, Israel
| | - Assaf Friedler
- 2 Institute of Chemistry, The Hebrew University of Jerusalem , Safra Campus Givat Ram, Jerusalem, Israel
| | - Dana Reichmann
- 1 Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, Safra Campus Givat Ram, The Hebrew University of Jerusalem , Jerusalem, Israel
| |
Collapse
|
29
|
Rutsdottir G, I Rasmussen M, Hojrup P, Bernfur K, Emanuelsson C, Söderberg CAG. Chaperone-client interactions between Hsp21 and client proteins monitored in solution by small angle X-ray scattering and captured by crosslinking mass spectrometry. Proteins 2017; 86:110-123. [PMID: 29082555 DOI: 10.1002/prot.25413] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2017] [Revised: 10/13/2017] [Accepted: 10/27/2017] [Indexed: 11/07/2022]
Abstract
The small heat shock protein (sHsp) chaperones are important for stress survival, yet the molecular details of how they interact with client proteins are not understood. All sHsps share a folded middle domain to which is appended flexible N- and C-terminal regions varying in length and sequence between different sHsps which, in different ways for different sHsps, mediate recognition of client proteins. In plants there is a chloroplast-localized sHsp, Hsp21, and a structural model suggests that Hsp21 has a dodecameric arrangement with six N-terminal arms located on the outside of the dodecamer and six inwardly-facing. Here, we investigated the interactions between Hsp21 and thermosensitive model substrate client proteins in solution, by small-angle X-ray scattering (SAXS) and crosslinking mass spectrometry. The chaperone-client complexes were monitored and the Rg -values were found to increase continuously during 20 min at 45°, which could reflect binding of partially unfolded clients to the flexible N-terminal arms of the Hsp21 dodecamer. No such increase in Rg -values was observed with a mutational variant of Hsp21, which is mainly dimeric and has reduced chaperone activity. Crosslinking data suggest that the chaperone-client interactions involve the N-terminal region in Hsp21 and only certain parts in the client proteins. These parts are peripheral structural elements presumably the first to unfold under destabilizing conditions. We propose that the flexible and hydrophobic N-terminal arms of Hsp21 can trap and refold early-unfolding intermediates with or without dodecamer dissociation.
Collapse
Affiliation(s)
- Gudrun Rutsdottir
- Department of Biochemistry and Structural Biology, Lund University, Sweden
| | - Morten I Rasmussen
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
| | - Peter Hojrup
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
| | - Katja Bernfur
- Department of Biochemistry and Structural Biology, Lund University, Sweden
| | | | | |
Collapse
|
30
|
Voth W, Jakob U. Stress-Activated Chaperones: A First Line of Defense. Trends Biochem Sci 2017; 42:899-913. [PMID: 28893460 DOI: 10.1016/j.tibs.2017.08.006] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Revised: 08/18/2017] [Accepted: 08/21/2017] [Indexed: 10/18/2022]
Abstract
Proteins are constantly challenged by environmental stress conditions that threaten their structure and function. Especially problematic are oxidative, acid, and severe heat stress which induce very rapid and widespread protein unfolding and generate conditions that make canonical chaperones and/or transcriptional responses inadequate to protect the proteome. We review here recent advances in identifying and characterizing stress-activated chaperones which are inactive under non-stress conditions but become potent chaperones under specific protein-unfolding stress conditions. We discuss the post-translational mechanisms by which these chaperones sense stress, and consider the role that intrinsic disorder plays in their regulation and function. We examine their physiological roles under both non-stress and stress conditions, their integration into the cellular proteostasis network, and their potential as novel therapeutic targets.
Collapse
Affiliation(s)
- Wilhelm Voth
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA; Department of Molecular Biology, Universitätsmedizin Göttingen, 37073 Göttingen, Germany
| | - Ursula Jakob
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA; Department of Biological Chemistry, University of Michigan, Ann Arbor, MI 48109, USA.
| |
Collapse
|
31
|
Rutsdottir G, Härmark J, Weide Y, Hebert H, Rasmussen MI, Wernersson S, Respondek M, Akke M, Højrup P, Koeck PJB, Söderberg CAG, Emanuelsson C. Structural model of dodecameric heat-shock protein Hsp21: Flexible N-terminal arms interact with client proteins while C-terminal tails maintain the dodecamer and chaperone activity. J Biol Chem 2017; 292:8103-8121. [PMID: 28325834 PMCID: PMC5427286 DOI: 10.1074/jbc.m116.766816] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Revised: 03/16/2017] [Indexed: 01/14/2023] Open
Abstract
Small heat-shock proteins (sHsps) prevent aggregation of thermosensitive client proteins in a first line of defense against cellular stress. The mechanisms by which they perform this function have been hard to define due to limited structural information; currently, there is only one high-resolution structure of a plant sHsp published, that of the cytosolic Hsp16.9. We took interest in Hsp21, a chloroplast-localized sHsp crucial for plant stress resistance, which has even longer N-terminal arms than Hsp16.9, with a functionally important and conserved methionine-rich motif. To provide a framework for investigating structure-function relationships of Hsp21 and understanding these sequence variations, we developed a structural model of Hsp21 based on homology modeling, cryo-EM, cross-linking mass spectrometry, NMR, and small-angle X-ray scattering. Our data suggest a dodecameric arrangement of two trimer-of-dimer discs stabilized by the C-terminal tails, possibly through tail-to-tail interactions between the discs, mediated through extended IXVXI motifs. Our model further suggests that six N-terminal arms are located on the outside of the dodecamer, accessible for interaction with client proteins, and distinct from previous undefined or inwardly facing arms. To test the importance of the IXVXI motif, we created the point mutant V181A, which, as expected, disrupts the Hsp21 dodecamer and decreases chaperone activity. Finally, our data emphasize that sHsp chaperone efficiency depends on oligomerization and that client interactions can occur both with and without oligomer dissociation. These results provide a generalizable workflow to explore sHsps, expand our understanding of sHsp structural motifs, and provide a testable Hsp21 structure model to inform future investigations.
Collapse
Affiliation(s)
| | - Johan Härmark
- the School of Technology and Health, KTH/Royal Institute of Technology and Department of Biosciences and Nutrition, Karolinska Institutet, SE-171 77 Stockholm, Sweden, and
| | - Yoran Weide
- From the Departments of Biochemistry and Structural Biology and
| | - Hans Hebert
- the School of Technology and Health, KTH/Royal Institute of Technology and Department of Biosciences and Nutrition, Karolinska Institutet, SE-171 77 Stockholm, Sweden, and
| | - Morten I Rasmussen
- the Department of Biochemistry and Molecular Biology, University of Southern Denmark, 5230 Odense, Denmark
| | | | | | | | - Peter Højrup
- the Department of Biochemistry and Molecular Biology, University of Southern Denmark, 5230 Odense, Denmark
| | - Philip J B Koeck
- the School of Technology and Health, KTH/Royal Institute of Technology and Department of Biosciences and Nutrition, Karolinska Institutet, SE-171 77 Stockholm, Sweden, and
| | | | | |
Collapse
|
32
|
Brandes N, Ofer D, Linial M. ASAP: a machine learning framework for local protein properties. Database (Oxford) 2016; 2016:baw133. [PMID: 27694209 PMCID: PMC5045867 DOI: 10.1093/database/baw133] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2016] [Revised: 08/08/2016] [Accepted: 08/28/2016] [Indexed: 11/14/2022]
Abstract
Determining residue-level protein properties, such as sites of post-translational modifications (PTMs), is vital to understanding protein function. Experimental methods are costly and time-consuming, while traditional rule-based computational methods fail to annotate sites lacking substantial similarity. Machine Learning (ML) methods are becoming fundamental in annotating unknown proteins and their heterogeneous properties. We present ASAP (Amino-acid Sequence Annotation Prediction), a universal ML framework for predicting residue-level properties. ASAP extracts numerous features from raw sequences, and supports easy integration of external features such as secondary structure, solvent accessibility, intrinsically disorder or PSSM profiles. Features are then used to train ML classifiers. ASAP can create new classifiers within minutes for a variety of tasks, including PTM prediction (e.g. cleavage sites by convertase, phosphoserine modification). We present a detailed case study for ASAP: CleavePred, an ASAP-based model to predict protein precursor cleavage sites, with state-of-the-art results. Protein cleavage is a PTM shared by a wide variety of proteins sharing minimal sequence similarity. Current rule-based methods suffer from high false positive rates, making them suboptimal. The high performance of CleavePred makes it suitable for analyzing new proteomes at a genomic scale. The tool is attractive to protein design, mass spectrometry search engines and the discovery of new bioactive peptides from precursors. ASAP functions as a baseline approach for residue-level protein sequence prediction. CleavePred is freely accessible as a web-based application. Both ASAP and CleavePred are open-source with a flexible Python API.Database URL: ASAP's and CleavePred source code, webtool and tutorials are available at: https://github.com/ddofer/asap; http://protonet.cs.huji.ac.il/cleavepred.
Collapse
Affiliation(s)
- Nadav Brandes
- Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, The Hebrew University, Jerusalem 91904, Israel
| | - Dan Ofer
- Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, The Hebrew University, Jerusalem 91904, Israel
| | - Michal Linial
- Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, The Hebrew University, Jerusalem 91904, Israel
| |
Collapse
|