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Diana D, Pirone L, Russo L, D'Abrosca G, Madheswaran M, Benfante R, Di Lascio S, Caldinelli L, Fornasari D, Acconcia C, Corvino A, Ventserova N, Pollegioni L, Isernia C, Di Gaetano S, Malgieri G, Pedone EM, Fattorusso R. Structural characterization of PHOX2B and its DNA interaction shed light on the molecular basis of the +7Ala variant pathogenicity in CCHS. Chem Sci 2024; 15:8858-8872. [PMID: 38873078 PMCID: PMC11168103 DOI: 10.1039/d3sc06427a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Accepted: 04/12/2024] [Indexed: 06/15/2024] Open
Abstract
An expansion of poly-alanine up to +13 residues in the C-terminus of the transcription factor PHOX2B underlies the onset of congenital central hypoventilation syndrome (CCHS). Recent studies demonstrated that the alanine tract expansion influences PHOX2B folding and activity. Therefore, structural information on PHOX2B is an important target for obtaining clues to elucidate the insurgence of the alanine expansion-related syndrome and also for defining a viable therapy. Here we report by NMR spectroscopy the structural characterization of the homeodomain (HD) of PHOX2B and HD + C-terminus PHOX2B protein, free and in the presence of the target DNA. The obtained structural data are then exploited to obtain a structural model of the PHOX2B-DNA interaction. In addition, the variant +7Ala, responsible for one of the most frequent forms of the syndrome, was analysed, showing different conformational proprieties in solution and a strong propensity to aggregation. Our data suggest that the elongated poly-alanine tract would be related to disease onset through a loss-of-function mechanism. Overall, this study paves the way for the future rational design of therapeutic drugs, suggesting as a possible therapeutic route the use of specific anti-aggregating molecules capable of preventing variant aggregation and possibly restoring the DNA-binding activity of PHOX2B.
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Affiliation(s)
- Donatella Diana
- CNR - Institute of Biostructures and Bioimaging Via Pietro Castellino 111 80131 Naples Italy
| | - Luciano Pirone
- CNR - Institute of Biostructures and Bioimaging Via Pietro Castellino 111 80131 Naples Italy
| | - Luigi Russo
- Department of Environmental, Biological and Pharmaceutical Sciences and Technologies - University of Campania "Luigi Vanvitelli" Via Vivaldi 43 81100 Caserta Italy
| | - Gianluca D'Abrosca
- Department of Clinical and Experimental Medicine - University of Foggia Viale Luigi Pinto 71122 Foggia Italy
| | - Manoj Madheswaran
- Department of Environmental, Biological and Pharmaceutical Sciences and Technologies - University of Campania "Luigi Vanvitelli" Via Vivaldi 43 81100 Caserta Italy
| | - Roberta Benfante
- Department of Medical Biotechnology and Translational Medicine (BIOMETRA), Università degli Studi di Milano Milan Italy
- CNR - Institute of Neuroscience Vedano Al Lambro (MB) Italy
- NeuroMi - Milan Center for Neuroscience, University of Milano Bicocca Milan Italy
| | - Simona Di Lascio
- Department of Medical Biotechnology and Translational Medicine (BIOMETRA), Università degli Studi di Milano Milan Italy
| | - Laura Caldinelli
- Department of Biotechnology and Life Sciences, University of Insubria Via J.H. Dunant 3 21100 Varese Italy
| | - Diego Fornasari
- Department of Medical Biotechnology and Translational Medicine (BIOMETRA), Università degli Studi di Milano Milan Italy
| | - Clementina Acconcia
- Department of Environmental, Biological and Pharmaceutical Sciences and Technologies - University of Campania "Luigi Vanvitelli" Via Vivaldi 43 81100 Caserta Italy
| | - Andrea Corvino
- Department of Environmental, Biological and Pharmaceutical Sciences and Technologies - University of Campania "Luigi Vanvitelli" Via Vivaldi 43 81100 Caserta Italy
| | - Nataliia Ventserova
- Department of Environmental, Biological and Pharmaceutical Sciences and Technologies - University of Campania "Luigi Vanvitelli" Via Vivaldi 43 81100 Caserta Italy
| | - Loredano Pollegioni
- Department of Biotechnology and Life Sciences, University of Insubria Via J.H. Dunant 3 21100 Varese Italy
| | - Carla Isernia
- Department of Environmental, Biological and Pharmaceutical Sciences and Technologies - University of Campania "Luigi Vanvitelli" Via Vivaldi 43 81100 Caserta Italy
| | - Sonia Di Gaetano
- CNR - Institute of Biostructures and Bioimaging Via Pietro Castellino 111 80131 Naples Italy
| | - Gaetano Malgieri
- Department of Environmental, Biological and Pharmaceutical Sciences and Technologies - University of Campania "Luigi Vanvitelli" Via Vivaldi 43 81100 Caserta Italy
| | - Emilia M Pedone
- CNR - Institute of Biostructures and Bioimaging Via Pietro Castellino 111 80131 Naples Italy
| | - Roberto Fattorusso
- Department of Environmental, Biological and Pharmaceutical Sciences and Technologies - University of Campania "Luigi Vanvitelli" Via Vivaldi 43 81100 Caserta Italy
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2
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Waszkiewicz R, Michaś A, Białobrzewski MK, Klepka BP, Cieplak-Rotowska MK, Staszałek Z, Cichocki B, Lisicki M, Szymczak P, Niedzwiecka A. Hydrodynamic Radii of Intrinsically Disordered Proteins: Fast Prediction by Minimum Dissipation Approximation and Experimental Validation. J Phys Chem Lett 2024; 15:5024-5033. [PMID: 38696815 PMCID: PMC11103702 DOI: 10.1021/acs.jpclett.4c00312] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2024] [Revised: 04/12/2024] [Accepted: 04/26/2024] [Indexed: 05/04/2024]
Abstract
The diffusion coefficients of globular and fully unfolded proteins can be predicted with high accuracy solely from their mass or chain length. However, this approach fails for intrinsically disordered proteins (IDPs) containing structural domains. We propose a rapid predictive methodology for estimating the diffusion coefficients of IDPs. The methodology uses accelerated conformational sampling based on self-avoiding random walks and includes hydrodynamic interactions between coarse-grained protein subunits, modeled using the generalized Rotne-Prager-Yamakawa approximation. To estimate the hydrodynamic radius, we rely on the minimum dissipation approximation recently introduced by Cichocki et al. Using a large set of experimentally measured hydrodynamic radii of IDPs over a wide range of chain lengths and domain contributions, we demonstrate that our predictions are more accurate than the Kirkwood approximation and phenomenological approaches. Our technique may prove to be valuable in predicting the hydrodynamic properties of both fully unstructured and multidomain disordered proteins.
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Affiliation(s)
- Radost Waszkiewicz
- Institute
of Theoretical Physics, Faculty of Physics, University of Warsaw, L. Pasteura 5, 02-093 Warsaw, Poland
| | - Agnieszka Michaś
- Institute
of Physics, Polish Academy of Sciences, Aleja Lotnikow 32/46, PL-02668 Warsaw, Poland
| | - Michał K. Białobrzewski
- Institute
of Physics, Polish Academy of Sciences, Aleja Lotnikow 32/46, PL-02668 Warsaw, Poland
| | - Barbara P. Klepka
- Institute
of Physics, Polish Academy of Sciences, Aleja Lotnikow 32/46, PL-02668 Warsaw, Poland
| | | | - Zuzanna Staszałek
- Institute
of Physics, Polish Academy of Sciences, Aleja Lotnikow 32/46, PL-02668 Warsaw, Poland
| | - Bogdan Cichocki
- Institute
of Theoretical Physics, Faculty of Physics, University of Warsaw, L. Pasteura 5, 02-093 Warsaw, Poland
| | - Maciej Lisicki
- Institute
of Theoretical Physics, Faculty of Physics, University of Warsaw, L. Pasteura 5, 02-093 Warsaw, Poland
| | - Piotr Szymczak
- Institute
of Theoretical Physics, Faculty of Physics, University of Warsaw, L. Pasteura 5, 02-093 Warsaw, Poland
| | - Anna Niedzwiecka
- Institute
of Physics, Polish Academy of Sciences, Aleja Lotnikow 32/46, PL-02668 Warsaw, Poland
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3
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Chou HY, Aksimentiev A. RNA regulates cohesiveness and porosity of a biological condensate. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.09.574811. [PMID: 38260307 PMCID: PMC10802450 DOI: 10.1101/2024.01.09.574811] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
Biological condensates have emerged as key elements of a biological cell function, concentrating disparate biomolecules to accomplish specific biological tasks. RNA was identified as a key ingredient of such condensates, however, its effect on the physical properties of the condensate was found to depend on the condensate's composition while its effect on the microstructure has remained elusive. Here, we characterize the physical properties and the microstructure of a protein-RNA condensate by means of large-scale coarse-grained (CG) molecular dynamics simulations. By developing a custom CG model of RNA compatible with a popular CG model of proteins, we systematically investigate the structural, thermodynamic, and kinetic properties of condensate droplets containing thousands of individual protein and RNA molecules over a range of temperatures. While we find RNA to increase the condensate's cohesiveness, its effect on the condensate's fluidity is more nuanced with longer molecules compacting the condensate and making it less fluid. We show that a biological condensate has a sponge-like morphology of interconnected channels of size that increases with temperature and decreases in the presence of RNA. Our results suggest that longer RNA form a dynamic scaffold within a condensate, regulating not only its fluidity but also permeability to intruder molecules.
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Rush C, Jiang Z, Tingey M, Feng F, Yang W. Unveiling the complexity: assessing models describing the structure and function of the nuclear pore complex. Front Cell Dev Biol 2023; 11:1245939. [PMID: 37876551 PMCID: PMC10591098 DOI: 10.3389/fcell.2023.1245939] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2023] [Accepted: 09/19/2023] [Indexed: 10/26/2023] Open
Abstract
The nuclear pore complex (NPC) serves as a pivotal subcellular structure, acting as a gateway that orchestrates nucleocytoplasmic transport through a selectively permeable barrier. Nucleoporins (Nups), particularly those containing phenylalanine-glycine (FG) motifs, play indispensable roles within this barrier. Recent advancements in technology have significantly deepened our understanding of the NPC's architecture and operational intricacies, owing to comprehensive investigations. Nevertheless, the conspicuous presence of intrinsically disordered regions within FG-Nups continues to present a formidable challenge to conventional static characterization techniques. Historically, a multitude of strategies have been employed to unravel the intricate organization and behavior of FG-Nups within the NPC. These endeavors have given rise to multiple models that strive to elucidate the structural layout and functional significance of FG-Nups. Within this exhaustive review, we present a comprehensive overview of these prominent models, underscoring their proposed dynamic and structural attributes, supported by pertinent research. Through a comparative analysis, we endeavor to shed light on the distinct characteristics and contributions inherent in each model. Simultaneously, it remains crucial to acknowledge the scarcity of unequivocal validation for any of these models, as substantiated by empirical evidence.
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Affiliation(s)
| | | | | | | | - Weidong Yang
- Department of Biology, Temple University, Philadelphia, PA, United States
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Minasbekyan LA, Badalyan HG. Physical model of the nuclear membrane permeability mechanism. Biophys Rev 2023; 15:1195-1207. [PMID: 37974978 PMCID: PMC10643749 DOI: 10.1007/s12551-023-01136-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Accepted: 08/31/2023] [Indexed: 11/19/2023] Open
Abstract
Nuclear cytoplasmic transport is mediated by many receptors that recognize specific nuclear localization signals on proteins and RNA and transport these substrates through nuclear pore complexes. Facilitated diffusion through nuclear pore complexes requires the attachment of transport receptors. Despite the relatively large tunnel diameter, some even small proteins (less than 20-30 kDa), such as histones, pass through the nuclear pore complex only with transport receptors. Over several decades, considerable material has been accumulated on the structure, architecture, and amino acid composition of the proteins included in this complex and the sequence of many receptors. We consider the data available in the literature on the structure of the nuclear pore complex and possible mechanisms of nuclear-cytoplasmic transport, applying the theory of electrostatic interactions in the context of our data on changes in the electrokinetic potential of nuclei and our previously proposed physical model of the mechanism of facilitated diffusion through the nuclear pore complex (NPC). According to our data, the main contribution to the charge of the nuclear membrane is made by anionic phospholipids, which are part of both the nuclear membrane and the nuclear matrix, which creates a potential difference between them. The nuclear membrane is a four-layer phospholipid dielectric, so the potential vector can only pass through the NPC, creating an electrostatic funnel that "pulls in" the positively charged load-NLS-NTR trigger complexes. Considering the newly obtained data, an improved model of the previously proposed physical model of the mechanism of nuclear-cytoplasmic transport is proposed. This model considers the contribution of electrostatic fields to the transportation speed when changing the membrane's thickness in the NPC basket at a higher load.
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Affiliation(s)
- Liya A. Minasbekyan
- Scientific Research Institute of Biology, Yerevan State University, A. Manoogian St., 1, 0025 Yerevan, Armenia
| | - Hamlet G. Badalyan
- Chair of General Physics, Yerevan State University, A. Manoogian St., 1, 0025 Yerevan, Armenia
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Minasbekyan LA, Badalyan HG. Physical model of the nuclear membrane permeability mechanism. Biophys Rev 2023; 15:1195-1207. [DOI: https:/doi.org/10.1007/s12551-023-01136-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Accepted: 08/31/2023] [Indexed: 02/27/2024] Open
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