1
|
Moses D, Guadalupe K, Yu F, Flores E, Perez AR, McAnelly R, Shamoon NM, Kaur G, Cuevas-Zepeda E, Merg AD, Martin EW, Holehouse AS, Sukenik S. Structural biases in disordered proteins are prevalent in the cell. Nat Struct Mol Biol 2024; 31:283-292. [PMID: 38177684 PMCID: PMC10873198 DOI: 10.1038/s41594-023-01148-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Accepted: 10/04/2023] [Indexed: 01/06/2024]
Abstract
Intrinsically disordered proteins and protein regions (IDPs) are prevalent in all proteomes and are essential to cellular function. Unlike folded proteins, IDPs exist in an ensemble of dissimilar conformations. Despite this structural plasticity, intramolecular interactions create sequence-specific structural biases that determine an IDP ensemble's three-dimensional shape. Such structural biases can be key to IDP function and are often measured in vitro, but whether those biases are preserved inside the cell is unclear. Here we show that structural biases in IDP ensembles found in vitro are recapitulated inside human-derived cells. We further reveal that structural biases can change in a sequence-dependent manner due to changes in the intracellular milieu, subcellular localization, and intramolecular interactions with tethered well-folded domains. We propose that the structural sensitivity of IDP ensembles can be leveraged for biological function, can be the underlying cause of IDP-driven pathology or can be used to design disorder-based biosensors and actuators.
Collapse
Affiliation(s)
- David Moses
- Department of Chemistry and Biochemistry, University of California, Merced, Merced, CA, USA
- Center for Cellular and Biomolecular Machines, University of California, Merced, Merced, CA, USA
| | - Karina Guadalupe
- Department of Chemistry and Biochemistry, University of California, Merced, Merced, CA, USA
- Center for Cellular and Biomolecular Machines, University of California, Merced, Merced, CA, USA
| | - Feng Yu
- Center for Cellular and Biomolecular Machines, University of California, Merced, Merced, CA, USA
- Quantitative and Systems Biology Program, University of California, Merced, Merced, CA, USA
| | - Eduardo Flores
- Department of Chemistry and Biochemistry, University of California, Merced, Merced, CA, USA
- Center for Cellular and Biomolecular Machines, University of California, Merced, Merced, CA, USA
| | - Anthony R Perez
- Department of Chemistry and Biochemistry, University of California, Merced, Merced, CA, USA
- Center for Cellular and Biomolecular Machines, University of California, Merced, Merced, CA, USA
| | - Ralph McAnelly
- Department of Chemistry and Biochemistry, University of California, Merced, Merced, CA, USA
| | - Nora M Shamoon
- Center for Cellular and Biomolecular Machines, University of California, Merced, Merced, CA, USA
- California State University, Stanislaus, Turlock, CA, USA
| | - Gagandeep Kaur
- Department of Chemistry and Biochemistry, University of California, Merced, Merced, CA, USA
| | | | - Andrea D Merg
- Department of Chemistry and Biochemistry, University of California, Merced, Merced, CA, USA
- Center for Cellular and Biomolecular Machines, University of California, Merced, Merced, CA, USA
| | - Erik W Martin
- Department of Structural Biology, St Jude Children's Research Hospital, Memphis, TN, USA
- Dewpoint Therapeutics, Boston, MA, USA
| | - Alex S Holehouse
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO, USA
- Center for Science and Engineering of Living Systems, Washington University in St. Louis, St. Louis, MO, USA
| | - Shahar Sukenik
- Department of Chemistry and Biochemistry, University of California, Merced, Merced, CA, USA.
- Center for Cellular and Biomolecular Machines, University of California, Merced, Merced, CA, USA.
- Quantitative and Systems Biology Program, University of California, Merced, Merced, CA, USA.
- Health Sciences Research Institute, University of California, Merced, Merced, CA, USA.
| |
Collapse
|
2
|
Epasto LM, Pötzl C, Peterlik H, Khalil M, Saint‐Pierre C, Gasparutto D, Sicoli G, Kurzbach D. NMR-identification of the interaction between BRCA1 and the intrinsically disordered monomer of the Myc-associated factor X. Protein Sci 2024; 33:e4849. [PMID: 38037490 PMCID: PMC10731500 DOI: 10.1002/pro.4849] [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: 09/20/2023] [Revised: 11/17/2023] [Accepted: 11/27/2023] [Indexed: 12/02/2023]
Abstract
The breast cancer susceptibility 1 (BRCA1) protein plays a pivotal role in modulating the transcriptional activity of the vital intrinsically disordered transcription factor MYC. In this regard, mutations of BRCA1 and interruption of its regulatory activity are related to hereditary breast and ovarian cancer (HBOC). Interestingly, so far, MYC's main dimerization partner MAX (MYC-associated factor X) has not been found to bind BRCA1 despite a high sequence similarity between both oncoproteins. Herein, we show that a potential reason for this discrepancy is the heterogeneous conformational space of MAX, which encloses a well-documented folded coiled-coil homodimer as well as a less common intrinsically disordered monomer state-contrary to MYC, which exists mostly as intrinsically disordered protein in the absence of any binding partner. We show that when the intrinsically disordered state of MAX is artificially overpopulated, the binding of MAX to BRCA1 can readily be observed. We characterize this interaction by nuclear magnetic resonance (NMR) spectroscopy chemical shift and relaxation measurements, complemented with ITC and SAXS data. Our results suggest that BRCA1 directly binds the MAX monomer to form a disordered complex. Though probed herein under biomimetic in-vitro conditions, this finding can potentially stimulate new perspectives on the regulatory network around BRCA1 and its involvement in MYC:MAX regulation.
Collapse
Affiliation(s)
- Ludovica Martina Epasto
- Faculty of Chemistry, Institute for Biological ChemistryUniversity of ViennaViennaAustria
- Vienna Doctoral School in Chemistry (DoSChem)University of ViennaViennaAustria
| | - Christopher Pötzl
- Faculty of Chemistry, Institute for Biological ChemistryUniversity of ViennaViennaAustria
- Vienna Doctoral School in Chemistry (DoSChem)University of ViennaViennaAustria
| | | | - Mahdi Khalil
- CNRS UMR 8516, LASIREUniversity of LilleVilleneuve d'Ascq CedexFrance
| | | | | | - Giuseppe Sicoli
- CNRS UMR 8516, LASIREUniversity of LilleVilleneuve d'Ascq CedexFrance
| | - Dennis Kurzbach
- Faculty of Chemistry, Institute for Biological ChemistryUniversity of ViennaViennaAustria
- Vienna Doctoral School in Chemistry (DoSChem)University of ViennaViennaAustria
| |
Collapse
|
3
|
Liu W, Chen L, Yin D, Yang Z, Feng J, Sun Q, Lai L, Guo X. Visualizing single-molecule conformational transition and binding dynamics of intrinsically disordered proteins. Nat Commun 2023; 14:5203. [PMID: 37626077 PMCID: PMC10457384 DOI: 10.1038/s41467-023-41018-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Accepted: 08/21/2023] [Indexed: 08/27/2023] Open
Abstract
Intrinsically disordered proteins (IDPs) play crucial roles in cellular processes and hold promise as drug targets. However, the dynamic nature of IDPs remains poorly understood. Here, we construct a single-molecule electrical nanocircuit based on silicon nanowire field-effect transistors (SiNW-FETs) and functionalize it with an individual disordered c-Myc bHLH-LZ domain to enable label-free, in situ, and long-term measurements at the single-molecule level. We use the device to study c-Myc interaction with Max and/or small molecule inhibitors. We observe the self-folding/unfolding process of c-Myc and reveal its interaction mechanism with Max and inhibitors through ultrasensitive real-time monitoring. We capture a relatively stable encounter intermediate ensemble of c-Myc during its transition from the unbound state to the fully folded state. The c-Myc/Max and c-Myc/inhibitor dissociation constants derived are consistent with other ensemble experiments. These proof-of-concept results provide an understanding of the IDP-binding/folding mechanism and represent a promising nanotechnology for IDP conformation/interaction studies and drug discovery.
Collapse
Affiliation(s)
- Wenzhe Liu
- Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, 292 Chengfu Road, Haidian District, 100871, Beijing, P. R. China
| | - Limin Chen
- Peking-Tsinghua Center for Life Sciences, Peking University, 100871, Beijing, P. R. China
| | - Dongbao Yin
- Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, 292 Chengfu Road, Haidian District, 100871, Beijing, P. R. China
| | - Zhiheng Yang
- Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, 292 Chengfu Road, Haidian District, 100871, Beijing, P. R. China
| | - Jianfei Feng
- Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, 292 Chengfu Road, Haidian District, 100871, Beijing, P. R. China
| | - Qi Sun
- Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, 292 Chengfu Road, Haidian District, 100871, Beijing, P. R. China.
| | - Luhua Lai
- Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, 292 Chengfu Road, Haidian District, 100871, Beijing, P. R. China.
- Peking-Tsinghua Center for Life Sciences, Peking University, 100871, Beijing, P. R. China.
- Center for Quantitative Biology, Academy for Advanced Interdisciplinary Studies, Peking University, 100871, Beijing, P. R. China.
| | - Xuefeng Guo
- Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, 292 Chengfu Road, Haidian District, 100871, Beijing, P. R. China.
- Center of Single-Molecule Sciences, Institute of Modern Optics, Frontiers Science Center for New Organic Matter, College of Electronic Information and Optical Engineering, Nankai University, 38 Tongyan Road, Jinnan District, 300350, Tianjin, P. R. China.
- National Biomedical Imaging Center, Peking University, Beijing, 100871, P. R. China.
| |
Collapse
|
4
|
Portability of a Small-Molecule Binding Site between Disordered Proteins. Biomolecules 2022; 12:biom12121887. [PMID: 36551315 PMCID: PMC9775153 DOI: 10.3390/biom12121887] [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: 10/04/2022] [Revised: 12/07/2022] [Accepted: 12/09/2022] [Indexed: 12/23/2022] Open
Abstract
Intrinsically disordered proteins (IDPs) are important in both normal and disease states. Small molecules can be targeted to disordered regions, but we currently have only a limited understanding of the nature of small-molecule binding sites in IDPs. Here, we show that a minimal small-molecule binding sequence of eight contiguous residues derived from the Myc protein can be ported into a different disordered protein and recapitulate small-molecule binding activity in the new context. We also find that the residue immediately flanking the binding site can have opposing effects on small-molecule binding in the different disordered protein contexts. The results demonstrate that small-molecule binding sites can act modularly and are portable between disordered protein contexts but that residues outside of the minimal binding site can modulate binding affinity.
Collapse
|
5
|
Dyson HJ, Wright PE. NMR illuminates intrinsic disorder. Curr Opin Struct Biol 2021; 70:44-52. [PMID: 33951592 DOI: 10.1016/j.sbi.2021.03.015] [Citation(s) in RCA: 46] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Accepted: 03/30/2021] [Indexed: 02/06/2023]
Abstract
Nuclear magnetic resonance (NMR) has long been instrumental in the characterization of intrinsically disordered proteins (IDPs) and intrinsically disordered regions (IDRs). This method continues to offer rich insights into the nature of IDPs in solution, especially in combination with other biophysical methods such as small-angle scattering, single-molecule fluorescence, electron paramagnetic resonance (EPR), and mass spectrometry. Substantial advances have been made in recent years in studies of proteins containing both ordered and disordered domains and in the characterization of problematic sequences containing repeated tracts of a single or a few amino acids. These sequences are relevant to disease states such as Alzheimer's, Parkinson's, and Huntington's diseases, where disordered proteins misfold into harmful amyloid. Innovative applications of NMR are providing novel insights into mechanisms of protein aggregation and the complexity of IDP interactions with their targets. As a basis for understanding the solution structural ensembles, dynamic behavior, and functional mechanisms of IDPs and IDRs, NMR continues to prove invaluable.
Collapse
Affiliation(s)
- H Jane Dyson
- Department of Integrative Structural and Computational Biology and Skaggs Institute of Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, 92037, California, USA
| | - Peter E Wright
- Department of Integrative Structural and Computational Biology and Skaggs Institute of Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, 92037, California, USA.
| |
Collapse
|
6
|
Kozak F, Kurzbach D. How to assess the structural dynamics of transcription factors by integrating sparse NMR and EPR constraints with molecular dynamics simulations. Comput Struct Biotechnol J 2021; 19:2097-2105. [PMID: 33995905 PMCID: PMC8085671 DOI: 10.1016/j.csbj.2021.04.020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Revised: 04/07/2021] [Accepted: 04/07/2021] [Indexed: 12/12/2022] Open
Abstract
We review recent advances in modeling structural ensembles of transcription factors from nuclear magnetic resonance (NMR) and electron paramagnetic resonance (EPR) spectroscopic data, integrated with molecular dynamics (MD) simulations. We focus on approaches that confirm computed conformational ensembles by sparse constraints obtained from magnetic resonance. This combination enables the deduction of functional and structural protein models even if nuclear Overhauser effects (NOEs) are too scarce for conventional structure determination. We highlight recent insights into the folding-upon-DNA binding transitions of intrinsically disordered transcription factors that could be assessed using such integrative approaches.
Collapse
Affiliation(s)
- Fanny Kozak
- University Vienna, Faculty of Chemistry, Institute of Biological Chemistry, Waehringer Str. 38, 1090 Vienna, Austria
| | - Dennis Kurzbach
- University Vienna, Faculty of Chemistry, Institute of Biological Chemistry, Waehringer Str. 38, 1090 Vienna, Austria
| |
Collapse
|
7
|
Novel NMR Assignment Strategy Reveals Structural Heterogeneity in Solution of the nsP3 HVD Domain of Venezuelan Equine Encephalitis Virus. Molecules 2020; 25:molecules25245824. [PMID: 33321815 PMCID: PMC7763327 DOI: 10.3390/molecules25245824] [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: 11/23/2020] [Revised: 12/04/2020] [Accepted: 12/08/2020] [Indexed: 11/17/2022] Open
Abstract
In recent years, intrinsically disordered proteins (IDPs) and disordered domains have attracted great attention. Many of them contain linear motifs that mediate interactions with other factors during formation of multicomponent protein complexes. NMR spectrometry is a valuable tool for characterizing this type of interactions on both amino acid (aa) and atomic levels. Alphaviruses encode a nonstructural protein nsP3, which drives viral replication complex assembly. nsP3 proteins contain over 200-aa-long hypervariable domains (HVDs), which exhibits no homology between different alphavirus species, are predicted to be intrinsically disordered and appear to be critical for alphavirus adaptation to different cells. Previously, we have shown that nsP3 HVD of chikungunya virus (CHIKV) is completely disordered with low tendency to form secondary structures in free form. In this new study, we used novel NMR approaches to assign the spectra for the nsP3 HVD of Venezuelan equine encephalitis virus (VEEV). The HVDs of CHIKV and VEEV have no homology but are both involved in replication complex assembly and function. We have found that VEEV nsP3 HVD is also mostly disordered but contains a short stable α-helix in its C-terminal fragment, which mediates interaction with the members of cellular Fragile X syndrome protein family. Our NMR data also suggest that VEEV HVD has several regions with tendency to form secondary structures.
Collapse
|
8
|
Sicoli G, Kress T, Vezin H, Ledolter K, Kurzbach D. A Switch between Two Intrinsically Disordered Conformational Ensembles Modulates the Active Site of a Basic-Helix-Loop-Helix Transcription Factor. J Phys Chem Lett 2020; 11:8944-8951. [PMID: 33030907 PMCID: PMC7649839 DOI: 10.1021/acs.jpclett.0c02242] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
We report a conformational switch between two distinct intrinsically disordered subensembles within the active site of a transcription factor. This switch highlights an evolutionary benefit conferred by the high plasticity of intrinsically disordered domains, namely, their potential to dynamically sample a heterogeneous conformational space housing multiple states with tailored properties. We focus on proto-oncogenic basic-helix-loop-helix (bHLH)-type transcription factors, as these play key roles in cell regulation and function. Despite intense research efforts, the understanding of structure-function relations of these transcription factors remains incomplete as they feature intrinsically disordered DNA-interaction domains that are difficult to characterize, theoretically as well as experimentally. Here we characterize the structural dynamics of the intrinsically disordered region DNA-binding site of the vital MYC-associated transcription factor X (MAX). Integrating nuclear magnetic resonance (NMR) measurements, molecular dynamics (MD) simulations, and electron paramagnetic resonance (EPR) measurements, we show that, in the absence of DNA, the binding site of the free MAX2 homodimer samples two intrinsically disordered conformational subensembles. These feature distinct structural properties: one subensemble consists of a set of highly flexible and spatially extended conformers, while the second features a set of "hinged" conformations. In this latter ensemble, the disordered N-terminal tails of MAX2 fold back along the dimer, forming transient long-range contacts with the HLH-region and thereby exposing the DNA binding site to the solvent. The features of these divergent substates suggest two mechanisms by which protein conformational dynamics in MAX2 might modulate DNA-complex formation: by enhanced initial recruitment of free DNA ligands, as a result of the wider conformational space sampled by the extended ensemble, and by direct exposure of the binding site and the corresponding strong electrostatic attractions presented while in the hinged conformations.
Collapse
Affiliation(s)
- Giuseppe Sicoli
- Laboratoire
Avancé de Spectroscopie pour les Interactions, la Réactivité
et l’Environnement (LASIRE), UMR CNRS 8516, Université de Lille, Avenue Paul Langevin − C4, F-59655 Villeneuve d’Ascq, France
| | - Thomas Kress
- Department
of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, U.K.
| | - Hervé Vezin
- Laboratoire
Avancé de Spectroscopie pour les Interactions, la Réactivité
et l’Environnement (LASIRE), UMR CNRS 8516, Université de Lille, Avenue Paul Langevin − C4, F-59655 Villeneuve d’Ascq, France
| | - Karin Ledolter
- Department
for Structural and Computational Biology, Max F. Perutz Laboratories, University Vienna, Campus Vienna BioCenter 5, 1030 Vienna, Austria
| | - Dennis Kurzbach
- Faculty
of Chemistry, Institute of Biological Chemistry, University of Vienna, Währinger Str. 38, 1090 Vienna, Austria
| |
Collapse
|
9
|
Truica MI, Burns MC, Han H, Abdulkadir SA. Turning Up the Heat on MYC: Progress in Small-Molecule Inhibitors. Cancer Res 2020; 81:248-253. [PMID: 33087323 DOI: 10.1158/0008-5472.can-20-2959] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Revised: 10/01/2020] [Accepted: 10/15/2020] [Indexed: 11/16/2022]
Abstract
MYC is a highly validated oncogenic transcription factor and cancer target. However, the disordered nature of this protein has made it a challenging target, with no clinical stage, direct small-molecule MYC inhibitors available. Recent work leveraging a large in silico chemical library and a rapid in vivo screen has expanded the chemotypes of direct small-molecule inhibitors (MYCi). Novel MYCi represent a class of improved MYC chemical probes that bind directly to MYC to inhibit its function and to promote its degradation by enhancing GSK3β-mediated phosphorylation. One of these compounds, MYCi975, has shown remarkable tolerability and efficacy in vivo and is associated with a selective effect on MYC target gene expression. Additional effects of MYCi on the tumor immune microenvironment including immune cell infiltration and upregulation of PD-L1 expression provide a rationale for combining MYCi with anti-PD-1/PD-L1 therapy to enhance antitumor efficacy. Our strategy for developing MYCi demonstrates an efficient way to identify selective and well-tolerated MYC inhibitors. The new MYCi provide tools for probing MYC function and serve as starting points for the development of novel anti-MYC therapeutics.
Collapse
Affiliation(s)
- Mihai I Truica
- Department of Urology, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Michael C Burns
- Department of Hematology-Oncology, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Huiying Han
- Department of Urology, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Sarki A Abdulkadir
- Department of Urology, Northwestern University Feinberg School of Medicine, Chicago, Illinois. .,The Robert H. Lurie Comprehensive Cancer Center, Northwestern University Feinberg School of Medicine, Chicago, Illinois.,Department of Pathology, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| |
Collapse
|
10
|
Na I, Choi S, Son SH, Uversky VN, Kim CG. Drug Discovery Targeting the Disorder-To-Order Transition Regions through the Conformational Diversity Mimicking and Statistical Analysis. Int J Mol Sci 2020; 21:ijms21155248. [PMID: 32722024 PMCID: PMC7432763 DOI: 10.3390/ijms21155248] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 07/11/2020] [Accepted: 07/21/2020] [Indexed: 12/22/2022] Open
Abstract
Intrinsically disordered proteins exist as highly dynamic conformational ensembles of diverse forms. However, the majority of virtual screening only focuses on proteins with defined structures. This means that computer-aided drug discovery is restricted. As a breakthrough, understanding the structural characteristics of intrinsically disordered proteins and its application can open the gate for unrestricted drug discovery. First, we segmented the target disorder-to-order transition region into a series of overlapping 20-amino-acid-long peptides. Folding prediction generated diverse conformations of these peptides. Next, we applied molecular docking, new evaluation score function, and statistical analysis. This approach successfully distinguished known compounds and their corresponding binding regions. Especially, Myc proto-oncogene protein (MYC) inhibitor 10058F4 was well distinguished from others of the chemical compound library. We also studied differences between the two Methyl-CpG-binding domain protein 2 (MBD2) inhibitors (ABA (2-amino-N-[[(3S)-2,3-dihydro-1,4-benzodioxin-3-yl]methyl]-acetamide) and APC ((R)-(3-(2-Amino-acetylamino)-pyrrolidine-1-carboxylic acid tert-butyl ester))). Both compounds bind MBD2 through electrostatic interaction behind its p66α-binding site. ABA is also able to bind p66α through electrostatic interaction behind its MBD2-binding site while APC-p66α binding was nonspecific. Therefore, structural heterogeneity mimicking of the disorder-to-order transition region at the peptide level and utilization of the new docking score function represent a useful approach that can efficiently discriminate compounds for expanded virtual screening toward intrinsically disordered proteins.
Collapse
Affiliation(s)
- Insung Na
- Department of Life Science and Research Institute for Natural Sciences, Hanyang University, Seoul 04763, Korea; (I.N.); (S.C.); (S.H.S.)
| | - Sungwoo Choi
- Department of Life Science and Research Institute for Natural Sciences, Hanyang University, Seoul 04763, Korea; (I.N.); (S.C.); (S.H.S.)
| | - Seung Han Son
- Department of Life Science and Research Institute for Natural Sciences, Hanyang University, Seoul 04763, Korea; (I.N.); (S.C.); (S.H.S.)
| | - Vladimir N. Uversky
- Department of Molecular Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL 33612, USA
- Institute for Biological Instrumentation of the Russian Academy of Sciences, 142290 Pushchino, Russia
- Correspondence: (V.N.U.); (C.G.K.)
| | - Chul Geun Kim
- Department of Life Science and Research Institute for Natural Sciences, Hanyang University, Seoul 04763, Korea; (I.N.); (S.C.); (S.H.S.)
- CGK Biopharma Co. Ltd., 222 Wangshipri-ro, Sungdong-gu, Seoul 04763, Korea
- Correspondence: (V.N.U.); (C.G.K.)
| |
Collapse
|
11
|
Beaulieu ME, Castillo F, Soucek L. Structural and Biophysical Insights into the Function of the Intrinsically Disordered Myc Oncoprotein. Cells 2020; 9:E1038. [PMID: 32331235 PMCID: PMC7226237 DOI: 10.3390/cells9041038] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Revised: 04/16/2020] [Accepted: 04/17/2020] [Indexed: 12/13/2022] Open
Abstract
Myc is a transcription factor driving growth and proliferation of cells and involved in the majority of human tumors. Despite a huge body of literature on this critical oncogene, our understanding of the exact molecular determinants and mechanisms that underlie its function is still surprisingly limited. Indubitably though, its crucial and non-redundant role in cancer biology makes it an attractive target. However, achieving successful clinical Myc inhibition has proven challenging so far, as this nuclear protein is an intrinsically disordered polypeptide devoid of any classical ligand binding pockets. Indeed, Myc only adopts a (partially) folded structure in some contexts and upon interacting with some protein partners, for instance when dimerizing with MAX to bind DNA. Here, we review the cumulative knowledge on Myc structure and biophysics and discuss the implications for its biological function and the development of improved Myc inhibitors. We focus this biophysical walkthrough mainly on the basic region helix-loop-helix leucine zipper motif (bHLHLZ), as it has been the principal target for inhibitory approaches so far.
Collapse
Affiliation(s)
| | | | - Laura Soucek
- Peptomyc S.L., Edifici Cellex, 08035 Barcelona, Spain; (F.C.); (L.S.)
- Vall d’Hebron Institute of Oncology (VHIO), Edifici Cellex, 08035 Barcelona, Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA), 08035 Barcelona, Spain
- Department of Biochemistry and Molecular Biology, Universitat Autònoma de Barcelona, 08035 Bellaterra, Spain
| |
Collapse
|
12
|
Massó-Vallés D, Beaulieu ME, Soucek L. MYC, MYCL, and MYCN as therapeutic targets in lung cancer. Expert Opin Ther Targets 2020; 24:101-114. [PMID: 32003251 DOI: 10.1080/14728222.2020.1723548] [Citation(s) in RCA: 64] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Introduction: Lung cancer is the leading cause of cancer-related mortality globally. Despite recent advances with personalized therapies and immunotherapy, the prognosis remains dire and recurrence is frequent. Myc is an oncogene deregulated in human cancers, including lung cancer, where it supports tumorigenic processes and progression. Elevated Myc levels have also been associated with resistance to therapy.Areas covered: This article summarizes the genomic and transcriptomic studies that compile evidence for (i) MYC, MYCN, and MYCL amplification and overexpression in lung cancer patients, and (ii) their prognostic significance. We collected the most recent literature regarding the development of Myc inhibitors where the emphasis is on those inhibitors tested in lung cancer experimental models and their potential for future clinical application.Expert opinion: The targeting of Myc in lung cancer is potentially an unprecedented opportunity for inhibiting a key player in tumor progression and maintenance and therapeutic resistance. Myc inhibitory strategies are on the path to their clinical application but further work is necessary for the assessment of their use in combination with standard treatment approaches. Given the role of Myc in immune suppression, a significant opportunity may exist in the combination of Myc inhibitors with immunotherapies.
Collapse
Affiliation(s)
| | | | - Laura Soucek
- Peptomyc S.L., Edifici Cellex, Hospital Vall d'Hebron, Barcelona, Spain.,Edifici Cellex, Vall d'Hebron Institute of Oncology (VHIO), Barcelona, Spain.,Institució Catalana De Recerca I Estudis Avançats (ICREA), Barcelona, Spain.,Department of Biochemistry and Molecular Biology, Universitat Autònoma De Barcelona, Bellaterra, Spain
| |
Collapse
|
13
|
Tarczewska A, Greb-Markiewicz B. The Significance of the Intrinsically Disordered Regions for the Functions of the bHLH Transcription Factors. Int J Mol Sci 2019; 20:E5306. [PMID: 31653121 PMCID: PMC6862971 DOI: 10.3390/ijms20215306] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 10/22/2019] [Accepted: 10/22/2019] [Indexed: 11/17/2022] Open
Abstract
The bHLH proteins are a family of eukaryotic transcription factors regulating expression of a wide range of genes involved in cell differentiation and development. They contain the Helix-Loop-Helix (HLH) domain, preceded by a stretch of basic residues, which are responsible for dimerization and binding to E-box sequences. In addition to the well-preserved DNA-binding bHLH domain, these proteins may contain various additional domains determining the specificity of performed transcriptional regulation. According to this, the family has been divided into distinct classes. Our aim was to emphasize the significance of existing disordered regions within the bHLH transcription factors for their functionality. Flexible, intrinsically disordered regions containing various motives and specific sequences allow for multiple interactions with transcription co-regulators. Also, based on in silico analysis and previous studies, we hypothesize that the bHLH proteins have a general ability to undergo spontaneous phase separation, forming or participating into liquid condensates which constitute functional centers involved in transcription regulation. We shortly introduce recent findings on the crucial role of the thermodynamically liquid-liquid driven phase separation in transcription regulation by disordered regions of regulatory proteins. We believe that further experimental studies should be performed in this field for better understanding of the mechanism of gene expression regulation (among others regarding oncogenes) by important and linked to many diseases the bHLH transcription factors.
Collapse
Affiliation(s)
- Aneta Tarczewska
- Department of Biochemistry, Faculty of Chemistry, Wroclaw University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wroclaw, Poland.
| | - Beata Greb-Markiewicz
- Department of Biochemistry, Faculty of Chemistry, Wroclaw University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wroclaw, Poland.
| |
Collapse
|