1
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Kulkarni P, Leite VBP, Roy S, Bhattacharyya S, Mohanty A, Achuthan S, Singh D, Appadurai R, Rangarajan G, Weninger K, Orban J, Srivastava A, Jolly MK, Onuchic JN, Uversky VN, Salgia R. Intrinsically disordered proteins: Ensembles at the limits of Anfinsen's dogma. BIOPHYSICS REVIEWS 2022; 3:011306. [PMID: 38505224 PMCID: PMC10903413 DOI: 10.1063/5.0080512] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Accepted: 02/17/2022] [Indexed: 03/21/2024]
Abstract
Intrinsically disordered proteins (IDPs) are proteins that lack rigid 3D structure. Hence, they are often misconceived to present a challenge to Anfinsen's dogma. However, IDPs exist as ensembles that sample a quasi-continuum of rapidly interconverting conformations and, as such, may represent proteins at the extreme limit of the Anfinsen postulate. IDPs play important biological roles and are key components of the cellular protein interaction network (PIN). Many IDPs can interconvert between disordered and ordered states as they bind to appropriate partners. Conformational dynamics of IDPs contribute to conformational noise in the cell. Thus, the dysregulation of IDPs contributes to increased noise and "promiscuous" interactions. This leads to PIN rewiring to output an appropriate response underscoring the critical role of IDPs in cellular decision making. Nonetheless, IDPs are not easily tractable experimentally. Furthermore, in the absence of a reference conformation, discerning the energy landscape representation of the weakly funneled IDPs in terms of reaction coordinates is challenging. To understand conformational dynamics in real time and decipher how IDPs recognize multiple binding partners with high specificity, several sophisticated knowledge-based and physics-based in silico sampling techniques have been developed. Here, using specific examples, we highlight recent advances in energy landscape visualization and molecular dynamics simulations to discern conformational dynamics and discuss how the conformational preferences of IDPs modulate their function, especially in phenotypic switching. Finally, we discuss recent progress in identifying small molecules targeting IDPs underscoring the potential therapeutic value of IDPs. Understanding structure and function of IDPs can not only provide new insight on cellular decision making but may also help to refine and extend Anfinsen's structure/function paradigm.
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Affiliation(s)
- Prakash Kulkarni
- Department of Medical Oncology and Therapeutics Research, City of Hope National Medical Center, Duarte, California 91010, USA
| | - Vitor B. P. Leite
- Departamento de Física, Instituto de Biociências, Letras e Ciências Exatas, Universidade Estadual Paulista (UNESP), São José do Rio Preto, São Paulo 15054-000, Brazil
| | - Susmita Roy
- Department of Chemical Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, West Bengal 741246, India
| | - Supriyo Bhattacharyya
- Translational Bioinformatics, Center for Informatics, Department of Computational and Quantitative Medicine, City of Hope National Medical Center, Duarte, California 91010, USA
| | - Atish Mohanty
- Department of Medical Oncology and Therapeutics Research, City of Hope National Medical Center, Duarte, California 91010, USA
| | - Srisairam Achuthan
- Center for Informatics, Division of Research Informatics, City of Hope National Medical Center, Duarte, California 91010, USA
| | - Divyoj Singh
- Center for BioSystems Science and Engineering, Indian Institute of Science, Bangalore 560012, India
| | - Rajeswari Appadurai
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore, Karnataka, India
| | - Govindan Rangarajan
- Department of Mathematics, Indian Institute of Science, Bangalore 560012, India
| | - Keith Weninger
- Department of Physics, North Carolina State University, Raleigh, North Carolina 27695, USA
| | | | - Anand Srivastava
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore, Karnataka, India
| | - Mohit Kumar Jolly
- Center for BioSystems Science and Engineering, Indian Institute of Science, Bangalore 560012, India
| | - Jose N. Onuchic
- Center for Theoretical Biological Physics, Rice University, Houston, Texas 77005-1892, USA
| | | | - Ravi Salgia
- Department of Medical Oncology and Therapeutics Research, City of Hope National Medical Center, Duarte, California 91010, USA
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2
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Malagrinò F, Diop A, Pagano L, Nardella C, Toto A, Gianni S. Unveiling induced folding of intrinsically disordered proteins - Protein engineering, frustration and emerging themes. Curr Opin Struct Biol 2021; 72:153-160. [PMID: 34902817 DOI: 10.1016/j.sbi.2021.11.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Revised: 10/26/2021] [Accepted: 11/01/2021] [Indexed: 01/01/2023]
Abstract
Intrinsically disordered proteins (IDPs) can be generally described as a class of proteins that lack a well-defined ordered structure in isolation at physiological conditions. Upon binding to their physiological ligands, IDPs typically undergo a disorder-to-order transition, which may or may not lead to the complete folding of the IDP. In this short review, we focus on some of the key findings pertaining to the mechanisms of such induced folding. In particular, first we describe the general features of the reaction; then, we discuss some of the most remarkable findings obtained from applying protein engineering in synergy with kinetic studies to induced folding; and finally, we offer a critical view on some of the emerging themes when considering the structural heterogeneity of IDPs vis-à-vis to their inherent frustration.
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Affiliation(s)
- Francesca Malagrinò
- Istituto Pasteur, Fondazione Cenci Bolognetti, Dipartimento di Scienze Biochimiche "A. Rossi Fanelli" and Istituto di Biologia e Patologia Molecolari Del CNR, Sapienza Università, di Roma, 00185, Rome, Italy
| | - Awa Diop
- Istituto Pasteur, Fondazione Cenci Bolognetti, Dipartimento di Scienze Biochimiche "A. Rossi Fanelli" and Istituto di Biologia e Patologia Molecolari Del CNR, Sapienza Università, di Roma, 00185, Rome, Italy
| | - Livia Pagano
- Istituto Pasteur, Fondazione Cenci Bolognetti, Dipartimento di Scienze Biochimiche "A. Rossi Fanelli" and Istituto di Biologia e Patologia Molecolari Del CNR, Sapienza Università, di Roma, 00185, Rome, Italy
| | - Caterina Nardella
- Istituto Pasteur, Fondazione Cenci Bolognetti, Dipartimento di Scienze Biochimiche "A. Rossi Fanelli" and Istituto di Biologia e Patologia Molecolari Del CNR, Sapienza Università, di Roma, 00185, Rome, Italy
| | - Angelo Toto
- Istituto Pasteur, Fondazione Cenci Bolognetti, Dipartimento di Scienze Biochimiche "A. Rossi Fanelli" and Istituto di Biologia e Patologia Molecolari Del CNR, Sapienza Università, di Roma, 00185, Rome, Italy.
| | - Stefano Gianni
- Istituto Pasteur, Fondazione Cenci Bolognetti, Dipartimento di Scienze Biochimiche "A. Rossi Fanelli" and Istituto di Biologia e Patologia Molecolari Del CNR, Sapienza Università, di Roma, 00185, Rome, Italy.
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3
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Karlsson E, Paissoni C, Erkelens AM, Tehranizadeh ZA, Sorgenfrei FA, Andersson E, Ye W, Camilloni C, Jemth P. Mapping the transition state for a binding reaction between ancient intrinsically disordered proteins. J Biol Chem 2021; 295:17698-17712. [PMID: 33454008 PMCID: PMC7762952 DOI: 10.1074/jbc.ra120.015645] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Revised: 10/15/2020] [Indexed: 12/24/2022] Open
Abstract
Intrinsically disordered protein domains often have multiple binding partners. It is plausible that the strength of pairing with specific partners evolves from an initial low affinity to a higher affinity. However, little is known about the molecular changes in the binding mechanism that would facilitate such a transition. We previously showed that the interaction between two intrinsically disordered domains, NCBD and CID, likely emerged in an ancestral deuterostome organism as a low-affinity interaction that subsequently evolved into a higher-affinity interaction before the radiation of modern vertebrate groups. Here we map native contacts in the transition states of the low-affinity ancestral and high-affinity human NCBD/CID interactions. We show that the coupled binding and folding mechanism is overall similar but with a higher degree of native hydrophobic contact formation in the transition state of the ancestral complex and more heterogeneous transient interactions, including electrostatic pairings, and an increased disorder for the human complex. Adaptation to new binding partners may be facilitated by this ability to exploit multiple alternative transient interactions while retaining the overall binding and folding pathway.
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Affiliation(s)
- Elin Karlsson
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - Cristina Paissoni
- Dipartimento di Bioscienze, Università degli Studi di Milano, Milano, Italy
| | - Amanda M Erkelens
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - Zeinab A Tehranizadeh
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden; Department of Medicinal Chemistry, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Frieda A Sorgenfrei
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - Eva Andersson
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - Weihua Ye
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - Carlo Camilloni
- Dipartimento di Bioscienze, Università degli Studi di Milano, Milano, Italy.
| | - Per Jemth
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden.
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4
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Gianni S, Jemth P. Affinity versus specificity in coupled binding and folding reactions. Protein Eng Des Sel 2020; 32:355-357. [PMID: 31397874 DOI: 10.1093/protein/gzz020] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Revised: 06/17/2019] [Accepted: 07/04/2019] [Indexed: 01/08/2023] Open
Abstract
Intrinsically disordered protein regions may fold upon binding to an interaction partner. It is often argued that such coupled binding and folding enables the combination of high specificity with low affinity. The basic tenet is that an unfavorable folding equilibrium will make the overall binding weaker while maintaining the interaction interface. While theoretically solid, we argue that this concept may be misleading for intrinsically disordered proteins. In fact, experimental evidence suggests that interactions of disordered regions usually involve extended conformations. In such cases, the disordered region is exceptionally unlikely to fold into a bound conformation in the absence of its binding partner. Instead, these disordered regions can bind to their partners in multiple different conformations and then fold into the native bound complex, thus, if anything, increasing the affinity through folding. We concede that (de)stabilization of native structural elements such as helices will modulate affinity, but this could work both ways, decreasing or increasing the stability of the complex. Moreover, experimental data show that intrinsically disordered binding regions display a range of affinities and specificities dictated by the particular side chains and length of the disordered region and not necessarily by the fact that they are disordered. We find it more likely that intrinsically disordered regions are common in protein-protein interactions because they increase the repertoire of binding partners, providing an accessible route to evolve interactions rather than providing a stability-affinity trade-off.
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Affiliation(s)
- Stefano Gianni
- Dipartimento di Scienze Biochimiche "A. Rossi Fanelli", Istituto Pasteur-Fondazione Cenci Bolognetti and Istituto di Biologia e Patologia Molecolari del CNR, Sapienza Università di Roma, Rome 00185, Italy
| | - Per Jemth
- Department of Medical Biochemistry and Microbiology, Uppsala University, BMC, Box 582, SE-75123 Uppsala, Sweden
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5
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Malagrinò F, Visconti L, Pagano L, Toto A, Troilo F, Gianni S. Understanding the Binding Induced Folding of Intrinsically Disordered Proteins by Protein Engineering: Caveats and Pitfalls. Int J Mol Sci 2020; 21:ijms21103484. [PMID: 32429036 PMCID: PMC7279032 DOI: 10.3390/ijms21103484] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2020] [Revised: 05/11/2020] [Accepted: 05/12/2020] [Indexed: 12/20/2022] Open
Abstract
Many proteins lack a well-defined three-dimensional structure in isolation. These proteins, typically denoted as intrinsically disordered proteins (IDPs), may display a characteristic disorder-to-order transition when binding their physiological partner(s). From an experimental perspective, it is of great importance to establish the general grounds to understand how such folding processes may be explored. Here we discuss the caveats and the pitfalls arising when applying to IDPs one of the key techniques to characterize the folding of globular proteins, the Φ value analysis. This method is based on measurements of the free energy changes of transition and native states upon conservative, non-disrupting, mutations. On the basis of available data, we reinforce the validity of Φ value analysis in the study of IDPs and suggest future experiments to further validate this powerful experimental method.
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6
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Chu WT, Shammas SL, Wang J. Charge Interactions Modulate the Encounter Complex Ensemble of Two Differently Charged Disordered Protein Partners of KIX. J Chem Theory Comput 2020; 16:3856-3868. [PMID: 32325001 DOI: 10.1021/acs.jctc.9b01264] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Disordered proteins play important roles in cell signaling and are frequently involved in protein-protein interactions. They also have a larger proportion of charged and polar residues than their folded counterparts. Here, we developed a structure-based model and applied molecular dynamics simulations to examine the presence and importance of electrostatic interactions in the binding processes of two differently charged intrinsically disordered ligands of the KIX domain of CBP. We observed non-native opposite-charged contacts in the encounter complexes for both ligands with KIX, and this may be a general feature of coupled folding and binding reactions. The ensemble of successful encounter complexes is a diverse set of structures, and in the case of the highly charged ligand, this ensemble was found to be malleable with respect to ionic strength. There are only minor differences between encounter complex ensembles for successful and unsuccessful collisions with no key interactions that appear to make the process far more productive. The energy landscape at this early stage in the process does not appear highly funneled. Strikingly we observed many native interactions that appear to reduce chances of an encounter complex being productive. Instead it appears that collectively non-native electrostatic interactions in the encounter complex increase the likelihood of productivity by holding the proteins together long enough for folding to take place. This mechanism is more effective for the more highly charged ligand.
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Affiliation(s)
- Wen-Ting Chu
- State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin 130022, P.R.China
| | - Sarah L Shammas
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, United Kingdom
| | - Jin Wang
- Department of Chemistry & Physics, State University of New York at Stony Brook, Stony Brook, New York 11794, United States
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7
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Toto A, Malagrinò F, Visconti L, Troilo F, Pagano L, Brunori M, Jemth P, Gianni S. Templated folding of intrinsically disordered proteins. J Biol Chem 2020; 295:6586-6593. [PMID: 32253236 DOI: 10.1074/jbc.rev120.012413] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Much of our current knowledge of biological chemistry is founded in the structure-function relationship, whereby sequence determines structure that determines function. Thus, the discovery that a large fraction of the proteome is intrinsically disordered, while being functional, has revolutionized our understanding of proteins and raised new and interesting questions. Many intrinsically disordered proteins (IDPs) have been determined to undergo a disorder-to-order transition when recognizing their physiological partners, suggesting that their mechanisms of folding are intrinsically different from those observed in globular proteins. However, IDPs also follow some of the classic paradigms established for globular proteins, pointing to important similarities in their behavior. In this review, we compare and contrast the folding mechanisms of globular proteins with the emerging features of binding-induced folding of intrinsically disordered proteins. Specifically, whereas disorder-to-order transitions of intrinsically disordered proteins appear to follow rules of globular protein folding, such as the cooperative nature of the reaction, their folding pathways are remarkably more malleable, due to the heterogeneous nature of their folding nuclei, as probed by analysis of linear free-energy relationship plots. These insights have led to a new model for the disorder-to-order transition in IDPs termed "templated folding," whereby the binding partner dictates distinct structural transitions en route to product, while ensuring a cooperative folding.
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Affiliation(s)
- Angelo Toto
- Istituto Pasteur-Fondazione Cenci Bolognetti, Dipartimento di Scienze Biochimiche "A. Rossi Fanelli" and Istituto di Biologia e Patologia Molecolari del CNR, Sapienza Università di Roma, 00185 Rome, Italy
| | - Francesca Malagrinò
- Istituto Pasteur-Fondazione Cenci Bolognetti, Dipartimento di Scienze Biochimiche "A. Rossi Fanelli" and Istituto di Biologia e Patologia Molecolari del CNR, Sapienza Università di Roma, 00185 Rome, Italy
| | - Lorenzo Visconti
- Istituto Pasteur-Fondazione Cenci Bolognetti, Dipartimento di Scienze Biochimiche "A. Rossi Fanelli" and Istituto di Biologia e Patologia Molecolari del CNR, Sapienza Università di Roma, 00185 Rome, Italy
| | - Francesca Troilo
- Istituto Pasteur-Fondazione Cenci Bolognetti, Dipartimento di Scienze Biochimiche "A. Rossi Fanelli" and Istituto di Biologia e Patologia Molecolari del CNR, Sapienza Università di Roma, 00185 Rome, Italy
| | - Livia Pagano
- Istituto Pasteur-Fondazione Cenci Bolognetti, Dipartimento di Scienze Biochimiche "A. Rossi Fanelli" and Istituto di Biologia e Patologia Molecolari del CNR, Sapienza Università di Roma, 00185 Rome, Italy
| | - Maurizio Brunori
- Istituto Pasteur-Fondazione Cenci Bolognetti, Dipartimento di Scienze Biochimiche "A. Rossi Fanelli" and Istituto di Biologia e Patologia Molecolari del CNR, Sapienza Università di Roma, 00185 Rome, Italy
| | - Per Jemth
- Department of Medical Biochemistry and Microbiology, Uppsala University, BMC Box 582, SE-75123 Uppsala, Sweden
| | - Stefano Gianni
- Istituto Pasteur-Fondazione Cenci Bolognetti, Dipartimento di Scienze Biochimiche "A. Rossi Fanelli" and Istituto di Biologia e Patologia Molecolari del CNR, Sapienza Università di Roma, 00185 Rome, Italy
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8
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Yang J, Gao M, Xiong J, Su Z, Huang Y. Features of molecular recognition of intrinsically disordered proteins via coupled folding and binding. Protein Sci 2019; 28:1952-1965. [PMID: 31441158 PMCID: PMC6798136 DOI: 10.1002/pro.3718] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Revised: 08/16/2019] [Accepted: 08/20/2019] [Indexed: 12/12/2022]
Abstract
The sequence-structure-function paradigm of proteins has been revolutionized by the discovery of intrinsically disordered proteins (IDPs) or intrinsically disordered regions (IDRs). In contrast to traditional ordered proteins, IDPs/IDRs are unstructured under physiological conditions. The absence of well-defined three-dimensional structures in the free state of IDPs/IDRs is fundamental to their function. Folding upon binding is an important mode of molecular recognition for IDPs/IDRs. While great efforts have been devoted to investigating the complex structures and binding kinetics and affinities, our knowledge on the binding mechanisms of IDPs/IDRs remains very limited. Here, we review recent advances on the binding mechanisms of IDPs/IDRs. The structures and kinetic parameters of IDPs/IDRs can vary greatly, and the binding mechanisms can be highly dependent on the structural properties of IDPs/IDRs. IDPs/IDRs can employ various combinations of conformational selection and induced fit in a binding process, which can be templated by the target and/or encoded by the IDP/IDR. Further studies should provide deeper insights into the molecular recognition of IDPs/IDRs and enable the rational design of IDP/IDR binding mechanisms in the future.
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Affiliation(s)
- Jing Yang
- Department of Biological Engineering and Key Laboratory of Industrial Fermentation (Ministry of Education)Hubei University of TechnologyWuhanHubeiChina
- Institute of Biomedical and Pharmaceutical SciencesHubei University of TechnologyWuhanHubeiChina
| | - Meng Gao
- Department of Biological Engineering and Key Laboratory of Industrial Fermentation (Ministry of Education)Hubei University of TechnologyWuhanHubeiChina
- Institute of Biomedical and Pharmaceutical SciencesHubei University of TechnologyWuhanHubeiChina
| | - Junwen Xiong
- Department of Biological Engineering and Key Laboratory of Industrial Fermentation (Ministry of Education)Hubei University of TechnologyWuhanHubeiChina
- Institute of Biomedical and Pharmaceutical SciencesHubei University of TechnologyWuhanHubeiChina
| | - Zhengding Su
- Department of Biological Engineering and Key Laboratory of Industrial Fermentation (Ministry of Education)Hubei University of TechnologyWuhanHubeiChina
- Institute of Biomedical and Pharmaceutical SciencesHubei University of TechnologyWuhanHubeiChina
| | - Yongqi Huang
- Department of Biological Engineering and Key Laboratory of Industrial Fermentation (Ministry of Education)Hubei University of TechnologyWuhanHubeiChina
- Institute of Biomedical and Pharmaceutical SciencesHubei University of TechnologyWuhanHubeiChina
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9
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Toto A, Troilo F, Visconti L, Malagrinò F, Bignon C, Longhi S, Gianni S. Binding induced folding: Lessons from the kinetics of interaction between N TAIL and XD. Arch Biochem Biophys 2019; 671:255-261. [PMID: 31326517 DOI: 10.1016/j.abb.2019.07.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2019] [Revised: 06/28/2019] [Accepted: 07/14/2019] [Indexed: 10/26/2022]
Abstract
Intrinsically Disordered Proteins (IDPs) are a class of protein that exert their function despite lacking a well-defined three-dimensional structure, which is sometimes achieved only upon binding to their natural ligands. This feature implies the folding of IDPs to be generally coupled with a binding event, representing an interesting challenge for kinetic studies. In this review, we recapitulate some of the most important findings of IDPs binding-induced folding mechanisms obtained by analyzing their binding kinetics. Furthermore, by focusing on the interaction between the Measles virus NTAIL protein, a prototypical IDP, and its physiological partner, the X domain, we recapitulate the major theoretical and experimental approaches that were used to describe binding induced folding.
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Affiliation(s)
- Angelo Toto
- Istituto Pasteur, Fondazione Cenci Bolognetti, Dipartimento di Scienze Biochimiche "A. Rossi Fanelli" and Istituto di Biologia e Patologia Molecolari del CNR, Sapienza Università di Roma, 00185, Rome, Italy
| | - Francesca Troilo
- Istituto Pasteur, Fondazione Cenci Bolognetti, Dipartimento di Scienze Biochimiche "A. Rossi Fanelli" and Istituto di Biologia e Patologia Molecolari del CNR, Sapienza Università di Roma, 00185, Rome, Italy
| | - Lorenzo Visconti
- Istituto Pasteur, Fondazione Cenci Bolognetti, Dipartimento di Scienze Biochimiche "A. Rossi Fanelli" and Istituto di Biologia e Patologia Molecolari del CNR, Sapienza Università di Roma, 00185, Rome, Italy
| | - Francesca Malagrinò
- Istituto Pasteur, Fondazione Cenci Bolognetti, Dipartimento di Scienze Biochimiche "A. Rossi Fanelli" and Istituto di Biologia e Patologia Molecolari del CNR, Sapienza Università di Roma, 00185, Rome, Italy
| | - Christophe Bignon
- Aix-Marseille University, CNRS, Architecture et Fonction des Macromolećules Biologiques (AFMB), UMR7257, Marseille, France
| | - Sonia Longhi
- Aix-Marseille University, CNRS, Architecture et Fonction des Macromolećules Biologiques (AFMB), UMR7257, Marseille, France.
| | - Stefano Gianni
- Istituto Pasteur, Fondazione Cenci Bolognetti, Dipartimento di Scienze Biochimiche "A. Rossi Fanelli" and Istituto di Biologia e Patologia Molecolari del CNR, Sapienza Università di Roma, 00185, Rome, Italy.
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10
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How Robust Is the Mechanism of Folding-Upon-Binding for an Intrinsically Disordered Protein? Biophys J 2019; 114:1889-1894. [PMID: 29694866 DOI: 10.1016/j.bpj.2018.03.017] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2018] [Revised: 03/15/2018] [Accepted: 03/20/2018] [Indexed: 12/18/2022] Open
Abstract
The mechanism of interaction of an intrinsically disordered protein (IDP) with its physiological partner is characterized by a disorder-to-order transition in which a recognition and a binding step take place. Even if the mechanism is quite complex, IDPs tend to bind their partner in a cooperative manner such that it is generally possible to detect experimentally only the disordered unbound state and the structured complex. The interaction between the disordered C-terminal domain of the measles virus nucleoprotein (NTAIL) and the X domain (XD) of the viral phosphoprotein allows us to detect and quantify the two distinct steps of the overall reaction. Here, we analyze the robustness of the folding of NTAIL upon binding to XD by measuring the effect on both the folding and binding steps of NTAIL when the structure of XD is modified. Because it has been shown that wild-type XD is structurally heterogeneous, populating an on-pathway intermediate under native conditions, we investigated the binding to 11 different site-directed variants of NTAIL of one particular variant of XD (I504A XD) that populates only the native state. Data reveal that the recognition and the folding steps are both affected by the structure of XD, indicating a highly malleable pathway. The experimental results are briefly discussed in the light of previous experiments on other IDPs.
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11
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Karlsson E, Andersson E, Dogan J, Gianni S, Jemth P, Camilloni C. A structurally heterogeneous transition state underlies coupled binding and folding of disordered proteins. J Biol Chem 2018; 294:1230-1239. [PMID: 30514761 PMCID: PMC6349112 DOI: 10.1074/jbc.ra118.005854] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Revised: 11/30/2018] [Indexed: 11/12/2022] Open
Abstract
Many intrinsically disordered proteins (IDPs) attain a well-defined structure in a coupled folding and binding reaction with another protein. Such reactions may involve early to late formation of different native structural regions along the reaction pathway. To obtain insights into the transition state for a coupled binding and folding reaction, we performed restrained molecular dynamics simulations using previously determined experimental binding Φb values of the interaction between two IDP domains: the activation domain from the p160 transcriptional co-activator for thyroid hormone and retinoid receptors (ACTR) and the nuclear co-activator binding domain (NCBD) of CREB-binding protein, each forming three well-defined α-helices upon binding. These simulations revealed that both proteins are largely disordered in the transition state for complex formation, except for two helices, one from each domain, that display a native-like structure. The overall transition state structure was extended and largely dynamic with many weakly populated contacts. To test the transition state model, we combined site-directed mutagenesis with kinetic experiments, yielding results consistent with overall diffuse interactions and formation of native intramolecular interactions in the third NCBD helix during the binding reaction. Our findings support the view that the transition state and, by inference, any encounter complex in coupled binding and folding reactions are structurally heterogeneous and largely independent of specific interactions. Furthermore, experimental Φb values and Brønsted plots suggested that the transition state is globally robust with respect to most mutations but can display more native-like features for some highly destabilizing mutations, possibly because of Hammond behavior or ground-state effects.
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Affiliation(s)
- Elin Karlsson
- Department of Medical Biochemistry and Microbiology, Uppsala University, SE-75123 Uppsala, Sweden
| | - Eva Andersson
- Department of Medical Biochemistry and Microbiology, Uppsala University, SE-75123 Uppsala, Sweden
| | - Jakob Dogan
- Department of Biochemistry and Biophysics, Stockholm University, SE-10691 Stockholm, Sweden
| | - Stefano Gianni
- Istituto Pasteur-Fondazione Cenci Bolognetti and Istituto di Biologia e Patologia Molecolari del CNR, Dipartimento di Scienze Biochimiche "A. Rossi Fanelli," Sapienza Università di Roma, 00185 Rome, Italy
| | - Per Jemth
- Department of Medical Biochemistry and Microbiology, Uppsala University, SE-75123 Uppsala, Sweden.
| | - Carlo Camilloni
- Dipartimento di Bioscienze, Università degli Studi di Milano, 20133 Milano, Italy.
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12
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Crabtree MD, Mendonça CATF, Bubb QR, Clarke J. Folding and binding pathways of BH3-only proteins are encoded within their intrinsically disordered sequence, not templated by partner proteins. J Biol Chem 2018; 293:9718-9723. [PMID: 29716994 PMCID: PMC6016464 DOI: 10.1074/jbc.ra118.002791] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Revised: 04/24/2018] [Indexed: 12/03/2022] Open
Abstract
Intrinsically disordered regions are present in one-third of eukaryotic proteins and are overrepresented in cellular processes such as signaling, suggesting that intrinsically disordered proteins (IDPs) may have a functional advantage over folded proteins. Upon interacting with a partner macromolecule, a subset of IDPs can fold and bind to form a well-defined three-dimensional conformation. For example, disordered BH3-only proteins bind promiscuously to a large number of homologous BCL-2 family proteins, where they fold to a helical structure in a groove on the BCL-2–like protein surface. As two protein chains are involved in the folding reaction, and the structure is only formed in the presence of the partner macromolecule, this raises the question of where the folding information is encoded. Here, we examine these coupled folding and binding reactions to determine which component determines the folding and binding pathway. Using Φ value analysis to compare transition state interactions between the disordered BH3-only proteins PUMA and BID and the folded BCL-2–like proteins A1 and MCL-1, we found that, even though the BH3-only protein is disordered in isolation and requires a stabilizing partner to fold, its folding and binding pathway is encoded in the IDP itself; the reaction is not templated by the folded partner. We suggest that, by encoding both its transition state and level of residual structure, an IDP can evolve a specific kinetic profile, which could be a crucial functional advantage of disorder.
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Affiliation(s)
- Michael D Crabtree
- From the Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, United Kingdom
| | - Carolina A T F Mendonça
- From the Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, United Kingdom
| | - Quenton R Bubb
- From the Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, United Kingdom
| | - Jane Clarke
- From the Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, United Kingdom
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13
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Dahal L, Kwan TOC, Shammas SL, Clarke J. pKID Binds to KIX via an Unstructured Transition State with Nonnative Interactions. Biophys J 2018; 113:2713-2722. [PMID: 29262364 PMCID: PMC5770965 DOI: 10.1016/j.bpj.2017.10.016] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Revised: 10/04/2017] [Accepted: 10/10/2017] [Indexed: 02/02/2023] Open
Abstract
Understanding the detailed mechanism of interaction of intrinsically disordered proteins with their partners is crucial to comprehend their functions in signaling and transcription. Through its interaction with KIX, the disordered pKID region of CREB protein is central in the transcription of cAMP responsive genes, including those involved in long-term memory. Numerous simulation studies have investigated these interactions. Combined with experimental results, these can provide valuable and comprehensive understanding of the mechanisms involved. Here, we probe the transition state of this interaction experimentally through analyzing the kinetic effect of mutating both interface and solvent exposed residues in pKID. We show that very few specific interactions between pKID and KIX are required in the initial binding process. Only a small number of weak interactions are formed at the transition state, including nonnative interactions, and most of the folding occurs after the initial binding event. These properties are consistent with computational results and also the majority of experimental studies of intrinsically disordered protein coupled folding and binding in other protein systems, suggesting that these may be common features.
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Affiliation(s)
- Liza Dahal
- Department of Chemistry, University of Cambridge, Cambridge, United Kingdom
| | - Tristan O C Kwan
- Department of Chemistry, University of Cambridge, Cambridge, United Kingdom
| | - Sarah L Shammas
- Department of Chemistry, University of Cambridge, Cambridge, United Kingdom.
| | - Jane Clarke
- Department of Chemistry, University of Cambridge, Cambridge, United Kingdom.
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14
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Affinity of IDPs to their targets is modulated by ion-specific changes in kinetics and residual structure. Proc Natl Acad Sci U S A 2017; 114:9882-9887. [PMID: 28847960 DOI: 10.1073/pnas.1705105114] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Intrinsically disordered proteins (IDPs) are characterized by a lack of defined structure. Instead, they populate ensembles of rapidly interconverting conformations with marginal structural stabilities. Changes in solution conditions such as temperature and crowding agents consequently affect IDPs more than their folded counterparts. Here we reveal that the residual structure content of IDPs is modulated both by ionic strength and by the type of ions present in solution. We show that these ion-specific structural changes result in binding affinity shifts of up to sixfold, which happen through alteration of both association and dissociation rates. These effects follow the Hofmeister series, but unlike the well-established effects on the stability of folded proteins, they already occur at low, hypotonic concentrations of salt. We attribute this sensitivity to the marginal stability of IDPs, which could have physiological implications given the role of IDPs in signaling, the asymmetric ion profiles of different cellular compartments, and the role of ions in biology.
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15
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Lindström I, Dogan J. Native Hydrophobic Binding Interactions at the Transition State for Association between the TAZ1 Domain of CBP and the Disordered TAD-STAT2 Are Not a Requirement. Biochemistry 2017; 56:4145-4153. [PMID: 28707474 DOI: 10.1021/acs.biochem.7b00428] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
A significant fraction of the eukaryotic proteome consists of proteins that are either partially or completely disordered under native-like conditions. Intrinsically disordered proteins (IDPs) are common in protein-protein interactions and are involved in numerous cellular processes. Although many proteins have been identified as disordered, much less is known about the binding mechanisms of the coupled binding and folding reactions involving IDPs. Here we have analyzed the rate-limiting transition state for binding between the TAZ1 domain of CREB binding protein and the intrinsically disordered transactivation domain of STAT2 (TAD-STAT2) by site-directed mutagenesis and kinetic experiments (Φ-value analysis) and found that the native protein-protein binding interface is not formed at the transition state for binding. Instead, native hydrophobic binding interactions form late, after the rate-limiting barrier has been crossed. The association rate constant in the absence of electrostatic enhancement was determined to be rather high. This is consistent with the Φ-value analysis, which showed that there are few or no obligatory native contacts. Also, linear free energy relationships clearly demonstrate that native interactions are cooperatively formed, a scenario that has usually been observed for proteins that fold according to the so-called nucleation-condensation mechanism. Thus, native hydrophobic binding interactions at the rate-limiting transition state for association between TAD-STAT2 and TAZ1 are not a requirement, which is generally in agreement with previous findings on other IDP systems and might be a common mechanism for IDPs.
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Affiliation(s)
- Ida Lindström
- Department of Biochemistry and Biophysics, Stockholm University , 10691 Stockholm, Sweden
| | - Jakob Dogan
- Department of Biochemistry and Biophysics, Stockholm University , 10691 Stockholm, Sweden
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16
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Troilo F, Bonetti D, Toto A, Visconti L, Brunori M, Longhi S, Gianni S. The Folding Pathway of the KIX Domain. ACS Chem Biol 2017; 12:1683-1690. [PMID: 28459531 DOI: 10.1021/acschembio.7b00289] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The KIX domain is an 89-residues globular domain with an important role in mediating protein-protein interactions. The presence of two distinct binding sites in such a small domain makes KIX a suitable candidate to investigate the effect of the potentially divergent demands between folding and function. Here, we report an extensive mutational analysis of the folding pathway of the KIX domain, based on 30 site-directed mutants, which allow us to assess the structures of both the transition and denatured states. Data reveal that, while the transition state presents mostly native-like interactions, the denatured state is somewhat misfolded. We mapped some of the non-native contacts in the denatured state using a second round of mutagenesis, based on double mutant cycles on 15 double mutants. Interestingly, such a misfolding arises from non-native interactions involving the residues critical for the function of the protein. The results described in this work appear to highlight the diverging demands between folding and function that may lead to misfolding, which may be observed in the early stages of folding.
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Affiliation(s)
- Francesca Troilo
- Istituto
Pasteur - Fondazione Cenci Bolognetti, Dipartimento di Scienze Biochimiche
“A. Rossi Fanelli” and Istituto di Biologia e Patologia
Molecolari del CNR, Sapienza Università di Roma, 00185, Rome, Italy
- Aix-Marseille Univ, CNRS, Architecture et Fonction des
Macromolécules Biologiques (AFMB), UMR 7257, 13288, Marseille, France
| | - Daniela Bonetti
- Istituto
Pasteur - Fondazione Cenci Bolognetti, Dipartimento di Scienze Biochimiche
“A. Rossi Fanelli” and Istituto di Biologia e Patologia
Molecolari del CNR, Sapienza Università di Roma, 00185, Rome, Italy
| | - Angelo Toto
- Istituto
Pasteur - Fondazione Cenci Bolognetti, Dipartimento di Scienze Biochimiche
“A. Rossi Fanelli” and Istituto di Biologia e Patologia
Molecolari del CNR, Sapienza Università di Roma, 00185, Rome, Italy
| | - Lorenzo Visconti
- Istituto
Pasteur - Fondazione Cenci Bolognetti, Dipartimento di Scienze Biochimiche
“A. Rossi Fanelli” and Istituto di Biologia e Patologia
Molecolari del CNR, Sapienza Università di Roma, 00185, Rome, Italy
| | - Maurizio Brunori
- Istituto
Pasteur - Fondazione Cenci Bolognetti, Dipartimento di Scienze Biochimiche
“A. Rossi Fanelli” and Istituto di Biologia e Patologia
Molecolari del CNR, Sapienza Università di Roma, 00185, Rome, Italy
| | - Sonia Longhi
- Aix-Marseille Univ, CNRS, Architecture et Fonction des
Macromolécules Biologiques (AFMB), UMR 7257, 13288, Marseille, France
| | - Stefano Gianni
- Istituto
Pasteur - Fondazione Cenci Bolognetti, Dipartimento di Scienze Biochimiche
“A. Rossi Fanelli” and Istituto di Biologia e Patologia
Molecolari del CNR, Sapienza Università di Roma, 00185, Rome, Italy
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17
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Crabtree MD, Borcherds W, Poosapati A, Shammas SL, Daughdrill GW, Clarke J. Conserved Helix-Flanking Prolines Modulate Intrinsically Disordered Protein:Target Affinity by Altering the Lifetime of the Bound Complex. Biochemistry 2017; 56:2379-2384. [PMID: 28425697 PMCID: PMC5467178 DOI: 10.1021/acs.biochem.7b00179] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
![]()
Appropriate
integration of cellular signals requires a delicate
balance of ligand–target binding affinities. Increasing the
level of residual structure in intrinsically disordered proteins (IDPs),
which are overrepresented in these cellular processes, has been shown
previously to enhance binding affinities and alter cellular function.
Conserved proline residues are commonly found flanking regions of
IDPs that become helical upon interacting with a partner protein.
Here, we mutate these helix-flanking prolines in p53 and MLL and find
opposite effects on binding affinity upon an increase in free IDP
helicity. In both cases, changes in affinity were due to alterations
in dissociation, not association, rate constants, which is inconsistent
with conformational selection mechanisms. We conclude that, contrary
to previous suggestions, helix-flanking prolines do not regulate affinity
by modulating the rate of complex formation. Instead, they influence
binding affinities by controlling the lifetime of the bound complex.
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Affiliation(s)
- Michael D Crabtree
- Department of Chemistry, University of Cambridge , Cambridge CB2 1EW, U.K
| | - Wade Borcherds
- Department of Cell Biology, Microbiology and Molecular Biology, University of South Florida , Tampa, Florida 33620, United States.,Florida Center for Drug Discovery and Innovation, University of South Florida , Tampa, Florida 33612, United States
| | - Anusha Poosapati
- Department of Cell Biology, Microbiology and Molecular Biology, University of South Florida , Tampa, Florida 33620, United States.,Florida Center for Drug Discovery and Innovation, University of South Florida , Tampa, Florida 33612, United States
| | - Sarah L Shammas
- Department of Chemistry, University of Cambridge , Cambridge CB2 1EW, U.K
| | - Gary W Daughdrill
- Department of Cell Biology, Microbiology and Molecular Biology, University of South Florida , Tampa, Florida 33620, United States.,Florida Center for Drug Discovery and Innovation, University of South Florida , Tampa, Florida 33612, United States
| | - Jane Clarke
- Department of Chemistry, University of Cambridge , Cambridge CB2 1EW, U.K
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