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Ferreon JC, Kongchan N, Tsoi PS, Choi KJ, Kenrick S, Neilson J, Ferreon ACM. Multivalent Protein-Nucleic Acid Interactions Probed by Composition-Gradient Multiangle Light Scattering. ACS OMEGA 2024; 9:41003-41010. [PMID: 39371993 PMCID: PMC11447847 DOI: 10.1021/acsomega.4c06358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/09/2024] [Revised: 09/13/2024] [Accepted: 09/18/2024] [Indexed: 10/08/2024]
Abstract
Many RNA-binding proteins, such as TDP-43 or CELF1, interact multivalently with nucleic acid repetitive elements. The molecular stoichiometry of protein to nucleic acid is often difficult to assess, particularly by standard electrophoretic mobility shift assays (EMSAs). Here, we investigate the use of composition-gradient multiangle light scattering (CG-MALS) for quantifying binding affinity and stoichiometry for two RNA-binding proteins with their nucleic acid partners of varied sequence and length: TDP43's N-terminal RNA recognition motifs with both TG/GU-repeat ssDNA and ssRNA, respectively, and CELF1's two N-terminal RNA recognition motifs with (TG/UGUU/GU) repeats and an experimentally defined cognate GU-rich element (GRE). Our CG-MALS data derived from each of these interactions is consistent with expected ranges of binding affinity and stoichiometry for proteins binding to shorter nucleic acid repeats. Furthermore, we conclude that CG-MALS can be an excellent method for obtaining quantitative estimates even for high (>2) protein-nucleic acid stoichiometric ratios.
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Affiliation(s)
- Josephine C. Ferreon
- Department
of Biochemistry and Molecular Pharmacology, Baylor College of Medicine, Houston, Texas 77030, United States
| | - Natee Kongchan
- Department
of Integrative Physiology, Baylor College
of Medicine, Houston, Texas 77030, United States
| | - Phoebe S. Tsoi
- Department
of Biochemistry and Molecular Pharmacology, Baylor College of Medicine, Houston, Texas 77030, United States
| | - Kyoung-Jae Choi
- Department
of Biochemistry and Molecular Pharmacology, Baylor College of Medicine, Houston, Texas 77030, United States
| | - Sophia Kenrick
- Wyatt
Technology, LLC, Santa Barbara, California 93111, United States
| | - Joel Neilson
- Department
of Integrative Physiology, Baylor College
of Medicine, Houston, Texas 77030, United States
| | - Allan Chris M. Ferreon
- Department
of Biochemistry and Molecular Pharmacology, Baylor College of Medicine, Houston, Texas 77030, United States
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2
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Hemphill WO, Steiner HR, Kominsky JR, Wuttke DS, Cech TR. Transcription factors ERα and Sox2 have differing multiphasic DNA- and RNA-binding mechanisms. RNA (NEW YORK, N.Y.) 2024; 30:1089-1105. [PMID: 38760076 PMCID: PMC11251522 DOI: 10.1261/rna.080027.124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2024] [Accepted: 05/01/2024] [Indexed: 05/19/2024]
Abstract
Many transcription factors (TFs) have been shown to bind RNA, leading to open questions regarding the mechanism(s) of this RNA binding and its role in regulating TF activities. Here, we use biophysical assays to interrogate the k on, k off, and K d for DNA and RNA binding of two model human TFs, ERα and Sox2. Unexpectedly, we found that both proteins exhibit multiphasic nucleic acid-binding kinetics. We propose that Sox2 RNA and DNA multiphasic binding kinetics can be explained by a conventional model for sequential Sox2 monomer association and dissociation. In contrast, ERα nucleic acid binding exhibited biphasic dissociation paired with novel triphasic association behavior, in which two apparent binding transitions are separated by a 10-20 min "lag" phase depending on protein concentration. We considered several conventional models for the observed kinetic behavior, none of which adequately explained all the ERα nucleic acid-binding data. Instead, simulations with a model incorporating sequential ERα monomer association, ERα nucleic acid complex isomerization, and product "feedback" on isomerization rate recapitulated the general kinetic trends for both ERα DNA and RNA binding. Collectively, our findings reveal that Sox2 and ERα bind RNA and DNA with previously unappreciated multiphasic binding kinetics, and that their reaction mechanisms differ with ERα binding nucleic acids via a novel reaction mechanism.
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Affiliation(s)
- Wayne O Hemphill
- Department of Biochemistry, University of Colorado Boulder, Boulder, Colorado 80303, USA
- Howard Hughes Medical Institute and BioFrontiers Institute, University of Colorado Boulder, Boulder, Colorado 80303, USA
| | - Halley R Steiner
- Department of Biochemistry, University of Colorado Boulder, Boulder, Colorado 80303, USA
| | - Jackson R Kominsky
- Department of Biochemistry, University of Colorado Boulder, Boulder, Colorado 80303, USA
- Howard Hughes Medical Institute and BioFrontiers Institute, University of Colorado Boulder, Boulder, Colorado 80303, USA
| | - Deborah S Wuttke
- Department of Biochemistry, University of Colorado Boulder, Boulder, Colorado 80303, USA
| | - Thomas R Cech
- Department of Biochemistry, University of Colorado Boulder, Boulder, Colorado 80303, USA
- Howard Hughes Medical Institute and BioFrontiers Institute, University of Colorado Boulder, Boulder, Colorado 80303, USA
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3
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Hemphill WO, Steiner HR, Kominsky JR, Wuttke DS, Cech TR. Transcription factors ERα and Sox2 have differing multiphasic DNA and RNA binding mechanisms. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.18.585577. [PMID: 38562825 PMCID: PMC10983890 DOI: 10.1101/2024.03.18.585577] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
Many transcription factors (TFs) have been shown to bind RNA, leading to open questions regarding the mechanism(s) of this RNA binding and its role in regulating TF activities. Here we use biophysical assays to interrogate the k o n , k o f f , and K d for DNA and RNA binding of two model human transcription factors, ERα and Sox2. Unexpectedly, we found that both proteins exhibited multiphasic nucleic acid binding kinetics. We propose that Sox2 RNA and DNA multiphasic binding kinetics could be explained by a conventional model for sequential Sox2 monomer association and dissociation. In contrast, ERα nucleic acid binding exhibited biphasic dissociation paired with novel triphasic association behavior, where two apparent binding transitions are separated by a 10-20 min "lag" phase depending on protein concentration. We considered several conventional models for the observed kinetic behavior, none of which adequately explained all the ERα nucleic acid binding data. Instead, simulations with a model incorporating sequential ERα monomer association, ERα nucleic acid complex isomerization, and product "feedback" on isomerization rate recapitulated the general kinetic trends for both ERα DNA and RNA binding. Collectively, our findings reveal that Sox2 and ERα bind RNA and DNA with previously unappreciated multiphasic binding kinetics, and that their reaction mechanisms differ with ERα binding nucleic acids via a novel reaction mechanism.
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Affiliation(s)
- Wayne O. Hemphill
- Department of Biochemistry, University of Colorado Boulder, Boulder, Colorado 80303 USA
- Howard Hughes Medical Institute and BioFrontiers Institute, University of Colorado Boulder, Boulder, Colorado 80303 USA
| | - Halley R. Steiner
- Department of Biochemistry, University of Colorado Boulder, Boulder, Colorado 80303 USA
| | - Jackson R. Kominsky
- Department of Biochemistry, University of Colorado Boulder, Boulder, Colorado 80303 USA
- Howard Hughes Medical Institute and BioFrontiers Institute, University of Colorado Boulder, Boulder, Colorado 80303 USA
| | - Deborah S. Wuttke
- Department of Biochemistry, University of Colorado Boulder, Boulder, Colorado 80303 USA
| | - Thomas R. Cech
- Department of Biochemistry, University of Colorado Boulder, Boulder, Colorado 80303 USA
- Howard Hughes Medical Institute and BioFrontiers Institute, University of Colorado Boulder, Boulder, Colorado 80303 USA
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4
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Hamilton DJ, Hein AE, Wuttke DS, Batey RT. The DNA binding high mobility group box protein family functionally binds RNA. WILEY INTERDISCIPLINARY REVIEWS. RNA 2023; 14:e1778. [PMID: 36646476 PMCID: PMC10349909 DOI: 10.1002/wrna.1778] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Revised: 12/22/2022] [Accepted: 12/27/2022] [Indexed: 01/18/2023]
Abstract
Nucleic acid binding proteins regulate transcription, splicing, RNA stability, RNA localization, and translation, together tailoring gene expression in response to stimuli. Upon discovery, these proteins are typically classified as either DNA or RNA binding as defined by their in vivo functions; however, recent evidence suggests dual DNA and RNA binding by many of these proteins. High mobility group box (HMGB) proteins have a DNA binding HMGB domain, act as transcription factors and chromatin remodeling proteins, and are increasingly understood to interact with RNA as means to regulate gene expression. Herein, multiple layers of evidence that the HMGB family are dual DNA and RNA binding proteins is comprehensively reviewed. For example, HMGB proteins directly interact with RNA in vitro and in vivo, are localized to RNP granules involved in RNA processing, and their protein interactors are enriched in RNA binding proteins involved in RNA metabolism. Importantly, in cell-based systems, HMGB-RNA interactions facilitate protein-protein interactions, impact splicing outcomes, and modify HMGB protein genomic or cellular localization. Misregulation of these HMGB-RNA interactions are also likely involved in human disease. This review brings to light that as a family, HMGB proteins are likely to bind RNA which is essential to HMGB protein biology. This article is categorized under: RNA Interactions with Proteins and Other Molecules > Protein-RNA Recognition RNA Interactions with Proteins and Other Molecules > RNA-Protein Complexes RNA Interactions with Proteins and Other Molecules > Protein-RNA Interactions: Functional Implications.
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Hamilton DJ, Hein AE, Holmes ZE, Wuttke DS, Batey RT. The DNA-Binding High-Mobility Group Box Domain of Sox Family Proteins Directly Interacts with RNA In Vitro. Biochemistry 2022; 61:10.1021/acs.biochem.2c00218. [PMID: 35511045 PMCID: PMC9636074 DOI: 10.1021/acs.biochem.2c00218] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
There is a growing body of evidence that a substantial number of protein domains identified as DNA-binding also interact with RNA to regulate biological processes. Several recent studies have revealed that the Sox2 transcription factor binds RNA through its high-mobility group box (HMGB) domain in vitro and in vivo. A high degree of conservation of this domain among members of the Sox family of transcription factors suggests that RNA-binding activity may be a general feature of these proteins. To address this hypothesis, we examined a subset of HMGB domains from human Sox family of proteins for their ability to bind both DNA and RNA in vitro. We observed selective, high-affinity interactions between Sox family HMGB domains and various model RNA elements, including a four-way junction RNA, a hairpin RNA with an internal bulge, G-quadruplex RNA, and a fragment of long noncoding RNA ES2, which is known to directly interact with Sox2. Importantly, the HMGB domains bind these RNA ligands significantly tighter than nonconsensus dsDNA and in some cases with affinities rivaling those of their consensus dsDNA sequences. These data suggest that RNA binding is a conserved feature of the Sox family of transcription factors with the potential to modulate unappreciated biological functions.
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Affiliation(s)
- Desmond J Hamilton
- Department of Biochemistry, University of Colorado Boulder, Boulder, Colorado 80309-0596, United States
| | - Abigail E Hein
- Department of Biochemistry, University of Colorado Boulder, Boulder, Colorado 80309-0596, United States
| | - Zachariah E Holmes
- Department of Biochemistry, University of Colorado Boulder, Boulder, Colorado 80309-0596, United States
| | - Deborah S Wuttke
- Department of Biochemistry, University of Colorado Boulder, Boulder, Colorado 80309-0596, United States
| | - Robert T Batey
- Department of Biochemistry, University of Colorado Boulder, Boulder, Colorado 80309-0596, United States
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6
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Liquid condensation of reprogramming factor KLF4 with DNA provides a mechanism for chromatin organization. Nat Commun 2021; 12:5579. [PMID: 34552088 PMCID: PMC8458463 DOI: 10.1038/s41467-021-25761-7] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Accepted: 08/31/2021] [Indexed: 12/29/2022] Open
Abstract
Expression of a few master transcription factors can reprogram the epigenetic landscape and three-dimensional chromatin topology of differentiated cells and achieve pluripotency. During reprogramming, thousands of long-range chromatin contacts are altered, and changes in promoter association with enhancers dramatically influence transcription. Molecular participants at these sites have been identified, but how this re-organization might be orchestrated is not known. Biomolecular condensation is implicated in subcellular organization, including the recruitment of RNA polymerase in transcriptional activation. Here, we show that reprogramming factor KLF4 undergoes biomolecular condensation even in the absence of its intrinsically disordered region. Liquid–liquid condensation of the isolated KLF4 DNA binding domain with a DNA fragment from the NANOG proximal promoter is enhanced by CpG methylation of a KLF4 cognate binding site. We propose KLF4-mediated condensation as one mechanism for selectively organizing and re-organizing the genome based on the local sequence and epigenetic state. KLF4, OCT4, SOX2 and MYC cooperate to reorganize chromatin during somatic cell reprogramming. Here the authors show that KLF4 forms a liquid-like biomolecular condensate that recruits OCT4 and SOX2, and that condensation of the isolated KLF4 DNA binding domain with DNA is enhanced by CpG methylation
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Tsubotani K, Maeyama S, Murakami S, Schaffer SW, Ito T. Taurine suppresses liquid-liquid phase separation of lysozyme protein. Amino Acids 2021; 53:745-751. [PMID: 33881613 DOI: 10.1007/s00726-021-02980-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Accepted: 04/08/2021] [Indexed: 01/11/2023]
Abstract
Taurine is a compatible osmolyte that confers stability to proteins. Recent studies have revealed that liquid-liquid phase separation (LLPS) of proteins underlie the formation of membraneless organelles in cells. In the present study, we evaluated the role of taurine on LLPS of hen egg lysozyme. We demonstrated that taurine decreases the turbidity of the polyethylene glycol-induced crowding solution of lysozyme. We also demonstrated that taurine attenuates LLPS-dependent cloudiness of lysozyme solution with 0.5 or 1 M NaCl at a critical temperature. Moreover, we observed that taurine inhibits LLPS formation of a heteroprotein mix solution of lysozyme and ovalbumin. These data indicate that taurine can modulate the formation of LLPS of proteins.
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Affiliation(s)
- Kanae Tsubotani
- Department of Biosciences and Biotechnology, Fukui Prefectural University, 4-1-1 Matsuokakenjojima, Eiheiji-cho, Yoshida-gun, Fukui, 910-1195, Japan
| | - Sayuri Maeyama
- Department of Biosciences and Biotechnology, Fukui Prefectural University, 4-1-1 Matsuokakenjojima, Eiheiji-cho, Yoshida-gun, Fukui, 910-1195, Japan
| | - Shigeru Murakami
- Department of Biosciences and Biotechnology, Fukui Prefectural University, 4-1-1 Matsuokakenjojima, Eiheiji-cho, Yoshida-gun, Fukui, 910-1195, Japan
| | - Stephen W Schaffer
- College of Medicine, University of South Alabama, 5795 Drive North, CSAB 170, Mobile, AL, 36688, USA
| | - Takashi Ito
- Department of Biosciences and Biotechnology, Fukui Prefectural University, 4-1-1 Matsuokakenjojima, Eiheiji-cho, Yoshida-gun, Fukui, 910-1195, Japan.
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8
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Holmes ZE, Hamilton DJ, Hwang T, Parsonnet NV, Rinn JL, Wuttke DS, Batey RT. The Sox2 transcription factor binds RNA. Nat Commun 2020; 11:1805. [PMID: 32286318 PMCID: PMC7156710 DOI: 10.1038/s41467-020-15571-8] [Citation(s) in RCA: 65] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Accepted: 03/18/2020] [Indexed: 01/06/2023] Open
Abstract
Certain transcription factors are proposed to form functional interactions with RNA to facilitate proper regulation of gene expression. Sox2, a transcription factor critical for maintenance of pluripotency and neurogenesis, has been found associated with several lncRNAs, although it is unknown whether these interactions are direct or via other proteins. Here we demonstrate that human Sox2 interacts directly with one of these lncRNAs with high affinity through its HMG DNA-binding domain in vitro. These interactions are primarily with double-stranded RNA in a non-sequence specific fashion, mediated by a similar but not identical interaction surface. We further determined that Sox2 directly binds RNA in mouse embryonic stem cells by UV-cross-linked immunoprecipitation of Sox2 and more than a thousand Sox2-RNA interactions in vivo were identified using fRIP-seq. Together, these data reveal that Sox2 employs a high-affinity/low-specificity paradigm for RNA binding in vitro and in vivo. Some transcription factors have been proposed to functionally interact with RNA to facilitate proper regulation of gene expression. Here the authors demonstrate that human Sox2 interact directly and with high affinity to RNAs through its HMG DNA-binding domain.
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Affiliation(s)
- Zachariah E Holmes
- Department of Biochemistry, University of Colorado at Boulder, Campus Box 596, Boulder, CO, 80309, USA
| | - Desmond J Hamilton
- Department of Biochemistry, University of Colorado at Boulder, Campus Box 596, Boulder, CO, 80309, USA
| | - Taeyoung Hwang
- Department of Biochemistry, University of Colorado at Boulder, Campus Box 596, Boulder, CO, 80309, USA
| | - Nicholas V Parsonnet
- Department of Biochemistry, University of Colorado at Boulder, Campus Box 596, Boulder, CO, 80309, USA
| | - John L Rinn
- Department of Biochemistry, University of Colorado at Boulder, Campus Box 596, Boulder, CO, 80309, USA.,BioFrontiers Institute, University of Colorado at Boulder, Campus Box 596, Boulder, CO, 80309, USA
| | - Deborah S Wuttke
- Department of Biochemistry, University of Colorado at Boulder, Campus Box 596, Boulder, CO, 80309, USA.
| | - Robert T Batey
- Department of Biochemistry, University of Colorado at Boulder, Campus Box 596, Boulder, CO, 80309, USA.
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9
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Simon I. Macromolecular Interactions of Disordered Proteins. Int J Mol Sci 2020; 21:ijms21020504. [PMID: 31941113 PMCID: PMC7014052 DOI: 10.3390/ijms21020504] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Revised: 01/08/2020] [Accepted: 01/10/2020] [Indexed: 02/03/2023] Open
Affiliation(s)
- István Simon
- Institute of Enzymology, RCNS, Lorand Eotvos Research Network, Center of Excellence of the Hungarian Academy of Sciences, Magyar Tudósok krt. 2., H-1117 Budapest, Hungary
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