1
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Shimamura H, Yamazaki H, Yoshimura SH. Charge block-driven liquid-liquid phase separation: A mechanism of how phosphorylation regulates phase behavior of disordered proteins. Biophys Physicobiol 2024; 21:e210012. [PMID: 39206127 PMCID: PMC11347820 DOI: 10.2142/biophysico.bppb-v21.0012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2024] [Accepted: 03/26/2024] [Indexed: 09/04/2024] Open
Abstract
Phosphorylation regulates protein function by modulating stereospecific interactions between protein-protein or enzyme-ligand. On the other hand, many bioinformatics studies have demonstrated that phosphorylation preferably occurs in intrinsically disordered regions (IDRs), which do not have any secondary and tertiary structures. Although studies have demonstrated that phosphorylation changes the phase behavior of IDRs, the mechanism, which is distinct from the "stereospecific" effect, had not been elucidated. Here, we describe how phosphorylation in IDRs regulates the protein function by modulating phase behavior. Mitotic phosphorylation in the IDRs of Ki-67 and NPM1 promotes or suppresses liquid-liquid phase separation, respectively, by altering the "charge blockiness" along the polypeptide chain. The phosphorylation-mediated regulation of liquid-liquid phase separation by enhancing or suppressing "charge blockiness," rather than by modulating stereospecific interactions, may provide one of the general mechanisms of protein regulation by posttranslational modifications and the role of multiple phosphorylations.
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Affiliation(s)
- Hisashi Shimamura
- Faculty of Integrated Human Science, Kyoto University, Kyoto 606-8501, Japan
| | - Hiroya Yamazaki
- Graduate School of Biostudies, Kyoto University, Kyoto 606-8501, Japan
| | - Shige H. Yoshimura
- Graduate School of Biostudies, Kyoto University, Kyoto 606-8501, Japan
- Center for Living Systems Information Science (CeLiSIS), Kyoto University, Kyoto 606-8501, Japan
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2
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Roopnarine O, Thomas DD. Structural Dynamics of Protein Interactions Using Site-Directed Spin Labeling of Cysteines to Measure Distances and Rotational Dynamics with EPR Spectroscopy. APPLIED MAGNETIC RESONANCE 2024; 55:79-100. [PMID: 38371230 PMCID: PMC10868710 DOI: 10.1007/s00723-023-01623-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Revised: 09/19/2023] [Accepted: 09/22/2023] [Indexed: 02/20/2024]
Abstract
Here we review applications of site-directed spin labeling (SDSL) with engineered cysteines in proteins, to study the structural dynamics of muscle and non-muscle proteins, using and developing the electron paramagnetic resonance (EPR) spectroscopic techniques of dipolar EPR, double electron electron resonance (DEER), saturation transfer EPR (STEPR), and orientation measured by EPR. The SDSL technology pioneered by Wayne Hubbell and collaborators has greatly expanded the use of EPR, including the measurement of distances between spin labels covalently attached to proteins and peptides. The Thomas lab and collaborators have applied these techniques to elucidate dynamic interactions in the myosin-actin complex, myosin-binding protein C, calmodulin, ryanodine receptor, phospholamban, utrophin, dystrophin, β-III-spectrin, and Aurora kinase. The ability to design and engineer cysteines in proteins for site-directed covalent labeling has enabled the use of these powerful EPR techniques to measure distances, while showing that they are complementary with optical spectroscopy measurements.
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Affiliation(s)
- Osha Roopnarine
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| | - David D. Thomas
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
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3
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Lasorsa A, Bera K, Malki I, Dupré E, Cantrelle FX, Merzougui H, Sinnaeve D, Hanoulle X, Hritz J, Landrieu I. Conformation and Affinity Modulations by Multiple Phosphorylation Occurring in the BIN1 SH3 Domain Binding Site of the Tau Protein Proline-Rich Region. Biochemistry 2023. [PMID: 37167199 DOI: 10.1021/acs.biochem.2c00717] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
An increase in phosphorylation of the Tau protein is associated with Alzheimer's disease (AD) progression through unclear molecular mechanisms. In general, phosphorylation modifies the interaction of intrinsically disordered proteins, such as Tau, with other proteins; however, elucidating the structural basis of this regulation mechanism remains challenging. The bridging integrator-1 gene is an AD genetic determinant whose gene product, BIN1, directly interacts with Tau. The proline-rich motif recognized within a Tau(210-240) peptide by the SH3 domain of BIN1 (BIN1 SH3) is defined as 216PTPP219, and this interaction is modulated by phosphorylation. Phosphorylation of T217 within the Tau(210-240) peptide led to a 6-fold reduction in the affinity, while single phosphorylation at either T212, T231, or S235 had no effect on the interaction. Nonetheless, combined phosphorylation of T231 and S235 led to a 3-fold reduction in the affinity, although these phosphorylations are not within the BIN1 SH3-bound region of the Tau peptide. Using nuclear magnetic resonance (NMR) spectroscopy, these phosphorylations were shown to affect the local secondary structure and dynamics of the Tau(210-240) peptide. Models of the (un)phosphorylated peptides were obtained from molecular dynamics (MD) simulation validated by experimental data and showed compaction of the phosphorylated peptide due to increased salt bridge formation. This dynamic folding might indirectly impact the BIN1 SH3 binding by a decreased accessibility of the binding site. Regulation of the binding might thus not only be due to local electrostatic or steric effects from phosphorylation but also to the modification of the conformational properties of Tau.
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Affiliation(s)
- Alessia Lasorsa
- CNRS EMR9002 Integrative Structural Biology, Lille F-59000, France
- Univ. Lille, Inserm, CHU Lille, Institut Pasteur de Lille, U1167 - RID-AGE - Risk Factors and Molecular Determinants of Aging-Related Diseases, Lille F-59000, France
| | - Krishnendu Bera
- CEITEC MU, Masaryk University, Kamenice 753/5, Brno 625 00, Czech Republic
- National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kamenice 5, Brno 625 00, Czech Republic
- Department of Chemistry, Faculty of Science, Masaryk University, Kamenice 5, Brno 625 00, Czech Republic
| | - Idir Malki
- CNRS EMR9002 Integrative Structural Biology, Lille F-59000, France
| | - Elian Dupré
- CNRS EMR9002 Integrative Structural Biology, Lille F-59000, France
- Univ. Lille, Inserm, CHU Lille, Institut Pasteur de Lille, U1167 - RID-AGE - Risk Factors and Molecular Determinants of Aging-Related Diseases, Lille F-59000, France
| | - François-Xavier Cantrelle
- CNRS EMR9002 Integrative Structural Biology, Lille F-59000, France
- Univ. Lille, Inserm, CHU Lille, Institut Pasteur de Lille, U1167 - RID-AGE - Risk Factors and Molecular Determinants of Aging-Related Diseases, Lille F-59000, France
| | - Hamida Merzougui
- CNRS EMR9002 Integrative Structural Biology, Lille F-59000, France
| | - Davy Sinnaeve
- CNRS EMR9002 Integrative Structural Biology, Lille F-59000, France
- Univ. Lille, Inserm, CHU Lille, Institut Pasteur de Lille, U1167 - RID-AGE - Risk Factors and Molecular Determinants of Aging-Related Diseases, Lille F-59000, France
| | - Xavier Hanoulle
- CNRS EMR9002 Integrative Structural Biology, Lille F-59000, France
- Univ. Lille, Inserm, CHU Lille, Institut Pasteur de Lille, U1167 - RID-AGE - Risk Factors and Molecular Determinants of Aging-Related Diseases, Lille F-59000, France
| | - Jozef Hritz
- CEITEC MU, Masaryk University, Kamenice 753/5, Brno 625 00, Czech Republic
- Department of Chemistry, Faculty of Science, Masaryk University, Kamenice 5, Brno 625 00, Czech Republic
| | - Isabelle Landrieu
- CNRS EMR9002 Integrative Structural Biology, Lille F-59000, France
- Univ. Lille, Inserm, CHU Lille, Institut Pasteur de Lille, U1167 - RID-AGE - Risk Factors and Molecular Determinants of Aging-Related Diseases, Lille F-59000, France
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4
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The Conformation of the Intrinsically Disordered N-Terminal Region of Barrier-to-Autointegration Factor (BAF) is Regulated by pH and Phosphorylation. J Mol Biol 2023; 435:167888. [PMID: 36402223 DOI: 10.1016/j.jmb.2022.167888] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Revised: 11/09/2022] [Accepted: 11/09/2022] [Indexed: 11/18/2022]
Abstract
Barrier-to-Autointegration Factor (BAF) is a highly conserved DNA binding protein important for genome integrity. Its localization and function are regulated through phosphorylation. Previously reported structures of BAF suggested that it is fully ordered, but our recent NMR analysis revealed that its N-terminal region is flexible in solution and that S4/T3 di-phosphorylation by VRK1 reduces this flexibility. Here, molecular dynamics (MD) simulation was used to unveil the conformational ensembles accessible to the N-terminal region of BAF either unphosphorylated, mono-phosphorylated on S4 or di-phosphorylated on S4/T3 (pBAF) and to reveal the interactions that contribute to define these ensembles. We show that the intrinsic flexibility observed in the N-terminal region of BAF is reduced by S4 phosphorylation and to a larger extent by S4/T3 di-phosphorylation. Thanks to the atomic description offered by MD supported by the NMR study of several BAF mutants, we identified the dynamic network of salt bridge interactions responsible for the conformational restriction involving pS4 and pT3 with residues located in helix α1 and α6. Using MD, we showed that the flexibility in the N-terminal region of BAF depends on the ionic strength and on the pH. We show that the presence of two negative charges of the phosphoryl groups is required for a substantial decrease in flexibility in pBAF. Using MD supported by NMR, we also showed that H7 deprotonation reduces the flexibility in the N-terminal region of BAF. Thus, the conformation of the intrinsically disordered N-terminal region of BAF is highly tunable, likely related to its diverse functions.
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5
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Zang Y, Wang H, Hao D, Kang Y, Zhang J, Li X, Zhang L, Yang Z, Zhang S. p38α Kinase Auto-Activation through Its Conformational Transition Induced by Tyr323 Phosphorylation. J Chem Inf Model 2022; 62:6639-6648. [PMID: 36394912 DOI: 10.1021/acs.jcim.2c00236] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
p38α is a key serine/threonine kinase that can enable atypical auto-activation through Zap70 phosphorylation and initiate T cell receptor signaling. The auto-activation plays an important role in autoimmune diseases. Although the classical activation mechanism of p38α has been studied in-depth, the atypical activation mechanism of Y323 phosphorylation-induced p38α auto-activation remains largely unexplained, especially the regulatory effects of phosphorylation on different sites (Y323 vs T180). From the X-ray experimental data, we identified the inactive and active states of p38α using principal component analysis. To understand the auto-activation process and the internal driving mechanism, a computational paradigm that couples the targeted molecular dynamics simulations, the String Method, and the umbrella sampling strategy were employed to generate the conformational landscape of p38α, including p38α T180-Y323, p38α T180-pY323, and p38α pT180-pY323 systems (pT180/pY323: phosphorylated T180/Y323). We explored that pY323 could change the conformational distribution and promote the conformational transition of p38α from the inactive state to the active state. Auto-activation of p38α is regulated by pY323 through destabilization of the hydrophobic core structure and aided by R173. This study will further explain the conformational transition of p38α induced by Y323 phosphorylation and provide insights into the universal molecular auto-activation mechanism of the p38 subfamily at the atomic level.
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Affiliation(s)
- Yongjian Zang
- MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter, School of Physics, Xi'an Jiaotong University, Xi'an710049, China
| | - He Wang
- MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter, School of Physics, Xi'an Jiaotong University, Xi'an710049, China
| | - Dongxiao Hao
- MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter, School of Physics, Xi'an Jiaotong University, Xi'an710049, China
| | - Ying Kang
- MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter, School of Physics, Xi'an Jiaotong University, Xi'an710049, China
| | - Jianwen Zhang
- MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter, School of Physics, Xi'an Jiaotong University, Xi'an710049, China
| | - Xuhua Li
- MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter, School of Physics, Xi'an Jiaotong University, Xi'an710049, China
| | - Lei Zhang
- MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter, School of Physics, Xi'an Jiaotong University, Xi'an710049, China
| | - Zhiwei Yang
- MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter, School of Physics, Xi'an Jiaotong University, Xi'an710049, China
| | - Shengli Zhang
- MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter, School of Physics, Xi'an Jiaotong University, Xi'an710049, China
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6
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Fernández-de Gortari E, Aguayo-Ortiz R, Autry JM, Michel Espinoza-Fonseca L. A hallmark of phospholamban functional divergence is located in the N-terminal phosphorylation domain. Comput Struct Biotechnol J 2020; 18:705-713. [PMID: 32257054 PMCID: PMC7114604 DOI: 10.1016/j.csbj.2020.02.016] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Revised: 02/23/2020] [Accepted: 02/23/2020] [Indexed: 01/12/2023] Open
Abstract
Sarcoplasmic reticulum Ca2+ pump (SERCA) is a critical component of the Ca2+ transport machinery in myocytes. There is clear evidence for regulation of SERCA activity by PLB, whose activity is modulated by phosphorylation of its N-terminal domain (residues 1–25), but there is less clear evidence for the role of this domain in PLB’s functional divergence. It is widely accepted that only sarcolipin (SLN), a protein that shares substantial homology with PLB, uncouples SERCA Ca2+ transport from ATP hydrolysis by inducing a structural change of its energy-transduction domain; yet, experimental evidence shows that the transmembrane domain of PLB (residues 26–52, PLB26–52) partially uncouples SERCA in vitro. These apparently conflicting mechanisms suggest that PLB’s uncoupling activity is encoded in its transmembrane domain, and that it is controlled by the N-terminal phosphorylation domain. To test this hypothesis, we performed molecular dynamics simulations (MDS) of the binary complex between PLB26–52 and SERCA. Comparison between PLB26–52 and wild-type PLB (PLBWT) showed no significant changes in the stability and orientation of the transmembrane helix, indicating that PLB26–52 forms a native-like complex with SERCA. MDS showed that PLB26–52 produces key intermolecular contacts and structural changes required for inhibition, in agreement with studies showing that PLB26–52 inhibits SERCA. However, deletion of the N-terminal phosphorylation domain facilitates an order-to-disorder shift in the energy-transduction domain associated with uncoupling of SERCA, albeit weaker than that induced by SLN. This mechanistic evidence reveals that the N-terminal phosphorylation domain of PLB is a primary contributor to the functional divergence among homologous SERCA regulators.
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Affiliation(s)
- Eli Fernández-de Gortari
- Center for Arrhythmia Research, Department of Internal Medicine, Division of Cardiovascular Medicine, University of Michigan, Ann Arbor, MI 48109, USA
| | - Rodrigo Aguayo-Ortiz
- Center for Arrhythmia Research, Department of Internal Medicine, Division of Cardiovascular Medicine, University of Michigan, Ann Arbor, MI 48109, USA
| | - Joseph M Autry
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA.,Biophysical Technology Center, University of Minnesota, Minneapolis, MN 55455, USA
| | - L Michel Espinoza-Fonseca
- Center for Arrhythmia Research, Department of Internal Medicine, Division of Cardiovascular Medicine, University of Michigan, Ann Arbor, MI 48109, USA
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7
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Kang W, Jiang F, Wu YD, Wales DJ. Multifunnel Energy Landscapes for Phosphorylated Translation Repressor 4E-BP2 and Its Mutants. J Chem Theory Comput 2019; 16:800-810. [PMID: 31774674 PMCID: PMC7462351 DOI: 10.1021/acs.jctc.9b01042] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Upon phosphorylation of specific sites, eukaryotic translation initiation factor 4E (eIF4E) binding protein 2 (4E-BP2) undergoes a fundamental structural transformation from a disordered state to a four-stranded β-sheet, leading to decreased binding affinity for its partner. This change reflects the significant effects of phosphate groups on the underlying energy landscapes of proteins. In this study, we combine high-temperature molecular dynamics simulations and discrete path sampling to construct energy landscapes for a doubly phosphorylated 4E-BP218-62 and two mutants (a single site mutant D33K and a double mutant Y54A/L59A). The potential and free energy landscapes for these three systems are multifunneled with the folded state and several alternative states lying close in energy, suggesting perhaps a multifunneled and multifunctional protein. Hydrogen bonds between phosphate groups and other residues not only stabilize these low-lying conformations to different extents but also play an important role in interstate transitions. From the energy landscape perspective, our results explain some interesting experimental observations, including the low stability of doubly phosphorylated 4E-BP2 and its moderate binding to eIF4E and the inability of phosphorylated Y54A/L59A to fold.
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Affiliation(s)
- Wei Kang
- Laboratory of Computational Chemistry and Drug Design, Laboratory of Chemical Genomics , Peking University Shenzhen Graduate School , Shenzhen 518055 , China.,College of Chemistry and Molecular Engineering , Peking University , Beijing 100871 , China.,Department of Chemistry , University of Cambridge , Lensfield Road , Cambridge CB2 1EW , U.K
| | - Fan Jiang
- Laboratory of Computational Chemistry and Drug Design, Laboratory of Chemical Genomics , Peking University Shenzhen Graduate School , Shenzhen 518055 , China
| | - Yun-Dong Wu
- Laboratory of Computational Chemistry and Drug Design, Laboratory of Chemical Genomics , Peking University Shenzhen Graduate School , Shenzhen 518055 , China.,College of Chemistry and Molecular Engineering , Peking University , Beijing 100871 , China
| | - David J Wales
- Department of Chemistry , University of Cambridge , Lensfield Road , Cambridge CB2 1EW , U.K
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8
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Hendus-Altenburger R, Fernandes CB, Bugge K, Kunze MBA, Boomsma W, Kragelund BB. Random coil chemical shifts for serine, threonine and tyrosine phosphorylation over a broad pH range. JOURNAL OF BIOMOLECULAR NMR 2019; 73:713-725. [PMID: 31598803 PMCID: PMC6875518 DOI: 10.1007/s10858-019-00283-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Accepted: 09/30/2019] [Indexed: 05/26/2023]
Abstract
Phosphorylation is one of the main regulators of cellular signaling typically occurring in flexible parts of folded proteins and in intrinsically disordered regions. It can have distinct effects on the chemical environment as well as on the structural properties near the modification site. Secondary chemical shift analysis is the main NMR method for detection of transiently formed secondary structure in intrinsically disordered proteins (IDPs) and the reliability of the analysis depends on an appropriate choice of random coil model. Random coil chemical shifts and sequence correction factors were previously determined for an Ac-QQXQQ-NH2-peptide series with X being any of the 20 common amino acids. However, a matching dataset on the phosphorylated states has so far only been incompletely determined or determined only at a single pH value. Here we extend the database by the addition of the random coil chemical shifts of the phosphorylated states of serine, threonine and tyrosine measured over a range of pH values covering the pKas of the phosphates and at several temperatures (www.bio.ku.dk/sbinlab/randomcoil). The combined results allow for accurate random coil chemical shift determination of phosphorylated regions at any pH and temperature, minimizing systematic biases of the secondary chemical shifts. Comparison of chemical shifts using random coil sets with and without inclusion of the phosphoryl group, revealed under/over estimations of helicity of up to 33%. The expanded set of random coil values will improve the reliability in detection and quantification of transient secondary structure in phosphorylation-modified IDPs.
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Affiliation(s)
- Ruth Hendus-Altenburger
- Structural Biology and NMR Laboratory, Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, 2200, Copenhagen N, Denmark
| | - Catarina B Fernandes
- Structural Biology and NMR Laboratory, Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, 2200, Copenhagen N, Denmark
| | - Katrine Bugge
- Structural Biology and NMR Laboratory, Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, 2200, Copenhagen N, Denmark
| | - Micha B A Kunze
- Structural Biology and NMR Laboratory, Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, 2200, Copenhagen N, Denmark
| | - Wouter Boomsma
- Department of Computer Science, University of Copenhagen, Universitetsparken 1, 2100, Copenhagen Ø, Denmark
| | - Birthe B Kragelund
- Structural Biology and NMR Laboratory, Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, 2200, Copenhagen N, Denmark.
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9
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Quantitative proteomics indicate a strong correlation of mitotic phospho-/dephosphorylation with non-structured regions of substrates. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2019; 1868:140295. [PMID: 31676455 DOI: 10.1016/j.bbapap.2019.140295] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2019] [Revised: 10/11/2019] [Accepted: 10/24/2019] [Indexed: 01/21/2023]
Abstract
Protein phosphorylation plays a critical role in the regulation and progression of mitosis. >40,000 phosphorylated residues and the associated kinases have been identified to date via proteomic analyses. Although some of these phosphosites are associated with regulation of either protein-protein interactions or the catalytic activity of the substrate protein, the roles of most mitotic phosphosites remain unclear. In this study, we examined structural properties of mitotic phosphosites and neighboring residues to understand the role of heavy phosphorylation in non-structured domains. Quantitative mass spectrometry analysis of mitosis-arrested and non-arrested HeLa cells revealed >4100 and > 2200 residues either significantly phosphorylated or dephosphorylated, respectively, at mitotic entry. The calculated disorder scores of amino acid sequences of neighboring individual phosphosites revealed that >70% of dephosphorylated phosphosites exist in disordered regions, whereas 50% of phosphorylated sites exist in non-structured domains. A clear inverse correlation was observed between probability of phosphorylation in non-structured domain and increment of phosphorylation in mitosis. These results indicate that at entry to mitosis, a significant number of phosphate groups are removed from non-structured domains and transferred to more-structured domains. Gene ontology term analysis revealed that mitosis-related proteins are heavily phosphorylated, whereas RNA-related proteins are both dephosphorylated and phosphorylated, suggesting that heavy phosphorylation/dephosphorylation in non-structured domains of RNA-binding proteins plays a role in dynamic rearrangement of RNA-containing organelles, as well as other intracellular environments.
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10
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Yang S, Lee KH, Woodhead JL, Sato O, Ikebe M, Craig R. The central role of the tail in switching off 10S myosin II activity. J Gen Physiol 2019; 151:1081-1093. [PMID: 31387899 PMCID: PMC6719407 DOI: 10.1085/jgp.201912431] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Accepted: 07/08/2019] [Indexed: 01/06/2023] Open
Abstract
Myosin II is a motor protein with two heads and an extended tail that plays an essential role in cell motility. Its active form is a polymer (myosin filament) that pulls on actin to generate motion. Its inactive form is a monomer with a compact structure (10S sedimentation coefficient), in which the tail is folded and the two heads interact with each other, inhibiting activity. This conformation is thought to function in cells as an energy-conserving form of the molecule suitable for storage as well as transport to sites of filament assembly. The mechanism of inhibition of the compact molecule is not fully understood. We have performed a 3-D reconstruction of negatively stained 10S myosin from smooth muscle in the inhibited state using single-particle analysis. The reconstruction reveals multiple interactions between the tail and the two heads that appear to trap ATP hydrolysis products, block actin binding, hinder head phosphorylation, and prevent filament formation. Blocking these essential features of myosin function could explain the high degree of inhibition of the folded form of myosin thought to underlie its energy-conserving function in cells. The reconstruction also suggests a mechanism for unfolding when myosin is activated by phosphorylation.
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Affiliation(s)
- Shixin Yang
- Division of Cell Biology and Imaging, Department of Radiology, University of Massachusetts Medical School, Worcester, MA
| | - Kyoung Hwan Lee
- Division of Cell Biology and Imaging, Department of Radiology, University of Massachusetts Medical School, Worcester, MA
| | - John L Woodhead
- Division of Cell Biology and Imaging, Department of Radiology, University of Massachusetts Medical School, Worcester, MA
| | - Osamu Sato
- Department of Cellular and Molecular Biology, University of Texas Health Science Center at Tyler, Tyler, TX
| | - Mitsuo Ikebe
- Department of Cellular and Molecular Biology, University of Texas Health Science Center at Tyler, Tyler, TX
| | - Roger Craig
- Division of Cell Biology and Imaging, Department of Radiology, University of Massachusetts Medical School, Worcester, MA
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11
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Tsytlonok M, Sanabria H, Wang Y, Felekyan S, Hemmen K, Phillips AH, Yun MK, Waddell MB, Park CG, Vaithiyalingam S, Iconaru L, White SW, Tompa P, Seidel CAM, Kriwacki R. Dynamic anticipation by Cdk2/Cyclin A-bound p27 mediates signal integration in cell cycle regulation. Nat Commun 2019; 10:1676. [PMID: 30976006 PMCID: PMC6459857 DOI: 10.1038/s41467-019-09446-w] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Accepted: 03/06/2019] [Indexed: 01/07/2023] Open
Abstract
p27Kip1 is an intrinsically disordered protein (IDP) that inhibits cyclin-dependent kinase (Cdk)/cyclin complexes (e.g., Cdk2/cyclin A), causing cell cycle arrest. Cell division progresses when stably Cdk2/cyclin A-bound p27 is phosphorylated on one or two structurally occluded tyrosine residues and a distal threonine residue (T187), triggering degradation of p27. Here, using an integrated biophysical approach, we show that Cdk2/cyclin A-bound p27 samples lowly-populated conformations that provide access to the non-receptor tyrosine kinases, BCR-ABL and Src, which phosphorylate Y88 or Y88 and Y74, respectively, thereby promoting intra-assembly phosphorylation (of p27) on distal T187. Even when tightly bound to Cdk2/cyclin A, intrinsic flexibility enables p27 to integrate and process signaling inputs, and generate outputs including altered Cdk2 activity, p27 stability, and, ultimately, cell cycle progression. Intrinsic dynamics within multi-component assemblies may be a general mechanism of signaling by regulatory IDPs, which can be subverted in human disease. The cyclin-dependent kinase (Cdk) inhibitor p27Kip1 (p27) folds upon binding to Cdk/cyclin complexes and during cell cycle progression p27 becomes phosphorylated, which triggers its ubiquitination and degradation. Here the authors use an integrated approach and show that Cdk2/cyclin A-bound p27 samples lowly-populated conformations that dynamically anticipate the sequential steps of the signaling cascade.
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Affiliation(s)
- Maksym Tsytlonok
- VIB Center for Structural Biology, Vrije Universiteit Brussel, Pleinlaan, 2 1050, Brussels, Belgium
| | - Hugo Sanabria
- Department of Physics and Astronomy, Clemson University, Clemson, SC, 29634, USA.,Lehrstuhl für Molekulare Physikalische Chemie, Heinrich-Heine-Universität, 40225, Düsseldorf, Germany
| | - Yuefeng Wang
- Department of Structural Biology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN, 38105, USA.,Department of Radiation Oncology, West Cancer Center and Research Institute, Memphis, TN, 38138, USA
| | - Suren Felekyan
- Lehrstuhl für Molekulare Physikalische Chemie, Heinrich-Heine-Universität, 40225, Düsseldorf, Germany
| | - Katherina Hemmen
- Lehrstuhl für Molekulare Physikalische Chemie, Heinrich-Heine-Universität, 40225, Düsseldorf, Germany
| | - Aaron H Phillips
- Department of Structural Biology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN, 38105, USA
| | - Mi-Kyung Yun
- Department of Structural Biology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN, 38105, USA
| | - M Brett Waddell
- Department of Structural Biology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN, 38105, USA.,Molecular Interaction Analysis Shared Resource, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN, 38103, USA
| | - Cheon-Gil Park
- Department of Structural Biology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN, 38105, USA
| | - Sivaraja Vaithiyalingam
- Department of Structural Biology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN, 38105, USA.,Molecular Interaction Analysis Shared Resource, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN, 38103, USA
| | - Luigi Iconaru
- Department of Structural Biology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN, 38105, USA
| | - Stephen W White
- Department of Structural Biology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN, 38105, USA
| | - Peter Tompa
- VIB Center for Structural Biology, Vrije Universiteit Brussel, Pleinlaan, 2 1050, Brussels, Belgium. .,Institute of Enzymology, Research Centre for Natural Sciences of the Hungarian Academy of Sciences, Budapest, Hungary.
| | - Claus A M Seidel
- Lehrstuhl für Molekulare Physikalische Chemie, Heinrich-Heine-Universität, 40225, Düsseldorf, Germany.
| | - Richard Kriwacki
- Department of Structural Biology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN, 38105, USA. .,Department of Microbiology, Immunology and Biochemistry, University of Tennessee Health Sciences Center, Memphis, TN, 38163, USA.
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12
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Sgrignani J, Chen J, Alimonti A, Cavalli A. How phosphorylation influences E1 subunit pyruvate dehydrogenase: A computational study. Sci Rep 2018; 8:14683. [PMID: 30279533 PMCID: PMC6168537 DOI: 10.1038/s41598-018-33048-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Accepted: 09/21/2018] [Indexed: 12/14/2022] Open
Abstract
Pyruvate (PYR) dehydrogenase complex (PDC) is an enzymatic system that plays a crucial role in cellular metabolism as it controls the entry of carbon into the Krebs cycle. From a structural point of view, PDC is formed by three different subunits (E1, E2 and E3) capable of catalyzing the three reaction steps necessary for the full conversion of pyruvate to acetyl-CoA. Recent investigations pointed out the crucial role of this enzyme in the replication and survival of specific cancer cell lines, renewing the interest of the scientific community. Here, we report the results of our molecular dynamics studies on the mechanism by which posttranslational modifications, in particular the phosphorylation of three serine residues (Ser-264-α, Ser-271-α, and Ser-203-α), influence the enzymatic function of the protein. Our results support the hypothesis that the phosphorylation of Ser-264-α and Ser-271-α leads to (1) a perturbation of the catalytic site structure and dynamics and, especially in the case of Ser-264-α, to (2) a reduction in the affinity of E1 for the substrate. Additionally, an analysis of the channels connecting the external environment with the catalytic site indicates that the inhibitory effect should not be due to the occlusion of the access/egress pathways to/from the active site.
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Affiliation(s)
- Jacopo Sgrignani
- Institute for Research in Biomedicine (IRB), Università della Svizzera Italiana (USI), Via Vincenzo Vela 6, CH-6500, Bellinzona, Switzerland.
- Swiss Institute of Bioinformatics, Lausanne, Switzerland.
| | - JingJing Chen
- Institute of Research in Oncology (IOR), Università della Svizzera Italiana (USI), Via Vincenzo Vela 6, CH-6500, Bellinzona, Switzerland
| | - Andrea Alimonti
- Institute of Research in Oncology (IOR), Università della Svizzera Italiana (USI), Via Vincenzo Vela 6, CH-6500, Bellinzona, Switzerland
| | - Andrea Cavalli
- Institute for Research in Biomedicine (IRB), Università della Svizzera Italiana (USI), Via Vincenzo Vela 6, CH-6500, Bellinzona, Switzerland.
- Swiss Institute of Bioinformatics, Lausanne, Switzerland.
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13
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Dahal L, Shammas SL, Clarke J. Phosphorylation of the IDP KID Modulates Affinity for KIX by Increasing the Lifetime of the Complex. Biophys J 2018; 113:2706-2712. [PMID: 29262363 PMCID: PMC5770967 DOI: 10.1016/j.bpj.2017.10.015] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [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: 11/17/2022] Open
Abstract
Intrinsically disordered proteins (IDPs) are known to undergo a range of posttranslational modifications, but by what mechanism do such modifications affect the binding of an IDP to its partner protein? We investigate this question using one such IDP, the kinase inducible domain (KID) of the transcription factor CREB, which interacts with the KIX domain of CREB-binding protein upon phosphorylation. As with many other IDPs, KID undergoes coupled folding and binding to form α-helical structure upon interacting with KIX. This single site phosphorylation plays an important role in the control of transcriptional activation in vivo. Here we show that, contrary to expectation, phosphorylation has no effect on association rates—unphosphorylated KID binds just as rapidly as pKID, the phosphorylated form—but rather, acts by increasing the lifetime of the complex. We propose that by controlling the lifetime of the bound complex of pKID:KIX via altering the dissociation rate, phosphorylation can facilitate effective control of transcription regulation.
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Affiliation(s)
- Liza Dahal
- 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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Alamo L, Koubassova N, Pinto A, Gillilan R, Tsaturyan A, Padrón R. Lessons from a tarantula: new insights into muscle thick filament and myosin interacting-heads motif structure and function. Biophys Rev 2017; 9:461-480. [PMID: 28871556 DOI: 10.1007/s12551-017-0295-1] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2017] [Accepted: 07/27/2017] [Indexed: 12/13/2022] Open
Abstract
The tarantula skeletal muscle X-ray diffraction pattern suggested that the myosin heads were helically arranged on the thick filaments. Electron microscopy (EM) of negatively stained relaxed tarantula thick filaments revealed four helices of heads allowing a helical 3D reconstruction. Due to its low resolution (5.0 nm), the unambiguous interpretation of densities of both heads was not possible. A resolution increase up to 2.5 nm, achieved by cryo-EM of frozen-hydrated relaxed thick filaments and an iterative helical real space reconstruction, allowed the resolving of both heads. The two heads, "free" and "blocked", formed an asymmetric structure named the "interacting-heads motif" (IHM) which explained relaxation by self-inhibition of both heads ATPases. This finding made tarantula an exemplar system for thick filament structure and function studies. Heads were shown to be released and disordered by Ca2+-activation through myosin regulatory light chain phosphorylation, leading to EM, small angle X-ray diffraction and scattering, and spectroscopic and biochemical studies of the IHM structure and function. The results from these studies have consequent implications for understanding and explaining myosin super-relaxed state and thick filament activation and regulation. A cooperative phosphorylation mechanism for activation in tarantula skeletal muscle, involving swaying constitutively Ser35 mono-phosphorylated free heads, explains super-relaxation, force potentiation and post-tetanic potentiation through Ser45 mono-phosphorylated blocked heads. Based on this mechanism, we propose a swaying-swinging, tilting crossbridge-sliding filament for tarantula muscle contraction.
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Affiliation(s)
- Lorenzo Alamo
- Centro de Biología Estructural "Humberto Fernández-Morán", Instituto Venezolano de Investigaciones Científicas (IVIC), Apdo. 20632, Caracas, 1020A, Venezuela
| | - Natalia Koubassova
- Institute of Mechanics, Moscow State University, Mitchurinsky prosp. 1, Moscow, 119992, Russia
| | - Antonio Pinto
- Centro de Biología Estructural "Humberto Fernández-Morán", Instituto Venezolano de Investigaciones Científicas (IVIC), Apdo. 20632, Caracas, 1020A, Venezuela
| | - Richard Gillilan
- Macromolecular Diffraction Facility, Cornell High Energy Synchrotron Source, Ithaca, NY, USA
| | - Andrey Tsaturyan
- Institute of Mechanics, Moscow State University, Mitchurinsky prosp. 1, Moscow, 119992, Russia
| | - Raúl Padrón
- Centro de Biología Estructural "Humberto Fernández-Morán", Instituto Venezolano de Investigaciones Científicas (IVIC), Apdo. 20632, Caracas, 1020A, Venezuela.
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15
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Hendus-Altenburger R, Lambrughi M, Terkelsen T, Pedersen SF, Papaleo E, Lindorff-Larsen K, Kragelund BB. A phosphorylation-motif for tuneable helix stabilisation in intrinsically disordered proteins - Lessons from the sodium proton exchanger 1 (NHE1). Cell Signal 2017; 37:40-51. [PMID: 28554535 DOI: 10.1016/j.cellsig.2017.05.015] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Revised: 05/24/2017] [Accepted: 05/25/2017] [Indexed: 11/26/2022]
Abstract
Intrinsically disordered proteins (IDPs) are involved in many pivotal cellular processes including phosphorylation and signalling. The structural and functional effects of phosphorylation of IDPs remain poorly understood and difficult to predict. Thus, a need exists to identify motifs that confer phosphorylation-dependent perturbation of the local preferences for forming e.g. helical structures as well as motifs that do not. The disordered distal tail of the Na+/H+ exchanger 1 (NHE1) is six-times phosphorylated (S693, S723, S726, S771, T779, S785) by the mitogen activated protein kinase 2 (MAPK1, ERK2). Using NMR spectroscopy, we found that two out of those six phosphorylation sites had a stabilizing effect on transient helices. One of these was further investigated by circular dichroism and NMR spectroscopy as well as by molecular dynamic simulations, which confirmed the stabilizing effect and resulted in the identification of a short linear motif for helix stabilisation: [S/T]-P-{3}-[R/K] where [S/T] is the phosphorylation-site. By analysing IDP and phosphorylation site databases we found that the motif is significantly enriched around known phosphorylation sites, supporting a potential wider-spread role in phosphorylation-mediated regulation of intrinsically disordered proteins. The identification of such motifs is important for understanding the molecular mechanism of cellular signalling, and is crucial for the development of predictors for the structural effect of phosphorylation; a tool of relevance for understanding disease-promoting mutations that for example interfere with signalling for instance through constitutive active and often cancer-promoting signalling.
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Affiliation(s)
- Ruth Hendus-Altenburger
- Structural Biology and NMR Laboratory, Linderstrøm-Lang Centre for Protein Science, Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, DK-2200 Copenhagen N, Denmark.
| | - Matteo Lambrughi
- Computational Biology Laboratory, Center for Autophagy, Recycling and Disease, Strandboulevarden 49, 2100 Copenhagen, Denmark.
| | - Thilde Terkelsen
- Computational Biology Laboratory, Center for Autophagy, Recycling and Disease, Strandboulevarden 49, 2100 Copenhagen, Denmark.
| | - Stine F Pedersen
- Cell Biology and Physiology, Department of Biology, University of Copenhagen, Universitetsparken 13, DK-2100 Copenhagen Ø, Denmark.
| | - Elena Papaleo
- Computational Biology Laboratory, Center for Autophagy, Recycling and Disease, Strandboulevarden 49, 2100 Copenhagen, Denmark.
| | - Kresten Lindorff-Larsen
- Structural Biology and NMR Laboratory, Linderstrøm-Lang Centre for Protein Science, Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, DK-2200 Copenhagen N, Denmark.
| | - Birthe B Kragelund
- Structural Biology and NMR Laboratory, Linderstrøm-Lang Centre for Protein Science, Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, DK-2200 Copenhagen N, Denmark.
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16
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Bomblies R, Luitz MP, Zacharias M. Molecular Dynamics Analysis of 4E-BP2 Protein Fold Stabilization Induced by Phosphorylation. J Phys Chem B 2016; 121:3387-3393. [PMID: 27776412 DOI: 10.1021/acs.jpcb.6b08597] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Protein phosphorylation can affect the interaction with partner proteins but can also induce conformational transitions. In case of the eukaryotic translation initiation factor 4E-binding protein 2 (4E-BP2) threonine (Thr) phosphorylation at two turn motifs results in transition from a disordered to a folded structure. In order to elucidate the stabilizing mechanism we employed comparative molecular dynamics (MD) free energy simulations on the turn motifs indicating that Thr-phosphorylation favors a folded whereas dephosphorylation or substitution by Glu residues destabilizes the turn structure. In multiple unrestrained MD simulations at elevated temperature of the 4E-BP2 domain only the double phosphorylated variant remained close to the folded structure in agreement with experiment. Three surface Arg residues were identified as additional key elements for the tertiary structure stabilization of the whole phosphorylated domain. In addition to the local turn structure double phosphorylation also leads to an overall electrostatic stabilization of the folded form compared to wild type and other investigated variants of 4E-BP2. The principles of phosphorylation mediated fold stabilization identified in the present study may also be helpful for identifying other structural motifs that can be affected by phosphorylation or provide a route to design such motifs.
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Affiliation(s)
- Rainer Bomblies
- Physik-Department T38, Technische Universität München , James-Franck-Str. 1, 85748 Garching, Germany
| | - Manuel P Luitz
- Physik-Department T38, Technische Universität München , James-Franck-Str. 1, 85748 Garching, Germany
| | - Martin Zacharias
- Physik-Department T38, Technische Universität München , James-Franck-Str. 1, 85748 Garching, Germany
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17
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Yu H, Chakravorty S, Song W, Ferenczi MA. Phosphorylation of the regulatory light chain of myosin in striated muscle: methodological perspectives. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2016; 45:779-805. [PMID: 27084718 PMCID: PMC5101276 DOI: 10.1007/s00249-016-1128-z] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Revised: 03/10/2016] [Accepted: 03/23/2016] [Indexed: 12/18/2022]
Abstract
Phosphorylation of the regulatory light chain (RLC) of myosin modulates cellular functions such as muscle contraction, mitosis, and cytokinesis. Phosphorylation defects are implicated in a number of diseases. Here we focus on striated muscle where changes in RLC phosphorylation relate to diseases such as hypertrophic cardiomyopathy and muscular dystrophy, or age-related changes. RLC phosphorylation in smooth muscle and non-muscle cells are covered briefly where relevant. There is much scientific interest in controlling the phosphorylation levels of RLC in vivo and in vitro in order to understand its physiological function in striated muscles. A summary of available and emerging in vivo and in vitro methods is presented. The physiological role of RLC phosphorylation and novel pathways are discussed to highlight the differences between muscle types and to gain insights into disease processes.
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Affiliation(s)
- Haiyang Yu
- Lee Kong Chian School of Medicine, Nanyang Technological University, Experimental Medicine Building, Level 3, 59 Nanyang Drive, Singapore, 636921, Singapore
| | - Samya Chakravorty
- Lee Kong Chian School of Medicine, Nanyang Technological University, Experimental Medicine Building, Level 3, 59 Nanyang Drive, Singapore, 636921, Singapore
| | - Weihua Song
- Lee Kong Chian School of Medicine, Nanyang Technological University, Experimental Medicine Building, Level 3, 59 Nanyang Drive, Singapore, 636921, Singapore
| | - Michael A Ferenczi
- Lee Kong Chian School of Medicine, Nanyang Technological University, Experimental Medicine Building, Level 3, 59 Nanyang Drive, Singapore, 636921, Singapore.
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18
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Espinoza-Fonseca LM, Alamo L, Pinto A, Thomas DD, Padrón R. Sequential myosin phosphorylation activates tarantula thick filament via a disorder-order transition. MOLECULAR BIOSYSTEMS 2016; 11:2167-79. [PMID: 26038232 DOI: 10.1039/c5mb00162e] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Phosphorylation of myosin regulatory light chain (RLC) N-terminal extension (NTE) activates myosin in thick filaments. RLC phosphorylation plays a primary regulatory role in smooth muscles and a secondary (modulatory) role in striated muscles, which is regulated by Ca(2+)via TnC/TM on the thin filament. Tarantula striated muscle exhibits both regulatory systems: one switches on/off contraction through thin filament regulation, and another through PKC constitutively Ser35 phosphorylated swaying free heads in the thick filaments that produces quick force on twitches regulated from 0 to 50% and modulation is accomplished recruiting additional force-potentiating free and blocked heads via Ca(2+)4-CaM-MLCK Ser45 phosphorylation. We have used microsecond molecular dynamics (MD) simulations of tarantula RLC NTE to understand the structural basis for phosphorylation-based regulation in tarantula thick filament activation. Trajectory analysis revealed that an inter-domain salt bridge network (R39/E58,E61) facilitates the formation of a stable helix-coil-helix (HCH) motif formed by helices P and A in the unphosphorylated NTE of both myosin heads. Phosphorylation of the blocked head on Ser45 does not induce any substantial structural changes. However, phosphorylation of the free head on Ser35 disrupts this salt bridge network and induces a partial extension of helix P along RLC helix A. While not directly participating in the HCH folding, phosphorylation of Ser35 unlocks a compact structure and allows the NTE to spontaneously undergo coil-helix transitions. The modest structural change induced by the subsequent Ser45 diphosphorylation monophosphorylated Ser35 free head facilitates full helix P extension into a single structurally stable α-helix through a network of intra-domain salt bridges (pS35/R38,R39,R42). We conclude that tarantula thick filament activation is controlled by sequential Ser35-Ser45 phosphorylation via a conserved disorder-to-order transition.
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Affiliation(s)
- L Michel Espinoza-Fonseca
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, Minnesota 55455, USA
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19
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Csizmok V, Follis AV, Kriwacki RW, Forman-Kay JD. Dynamic Protein Interaction Networks and New Structural Paradigms in Signaling. Chem Rev 2016; 116:6424-62. [PMID: 26922996 DOI: 10.1021/acs.chemrev.5b00548] [Citation(s) in RCA: 133] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Understanding signaling and other complex biological processes requires elucidating the critical roles of intrinsically disordered proteins (IDPs) and regions (IDRs), which represent ∼30% of the proteome and enable unique regulatory mechanisms. In this review, we describe the structural heterogeneity of disordered proteins that underpins these mechanisms and the latest progress in obtaining structural descriptions of conformational ensembles of disordered proteins that are needed for linking structure and dynamics to function. We describe the diverse interactions of IDPs that can have unusual characteristics such as "ultrasensitivity" and "regulated folding and unfolding". We also summarize the mounting data showing that large-scale assembly and protein phase separation occurs within a variety of signaling complexes and cellular structures. In addition, we discuss efforts to therapeutically target disordered proteins with small molecules. Overall, we interpret the remodeling of disordered state ensembles due to binding and post-translational modifications within an expanded framework for allostery that provides significant insights into how disordered proteins transmit biological information.
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Affiliation(s)
- Veronika Csizmok
- Molecular Structure & Function, The Hospital for Sick Children , Toronto, ON M5G 0A4, Canada
| | - Ariele Viacava Follis
- Department of Structural Biology, St. Jude Children's Research Hospital , Memphis, Tennessee 38105, United States
| | - Richard W Kriwacki
- Department of Structural Biology, St. Jude Children's Research Hospital , Memphis, Tennessee 38105, United States.,Department of Microbiology, Immunology and Biochemistry, University of Tennessee Health Sciences Center , Memphis, Tennessee 38163, United States
| | - Julie D Forman-Kay
- Molecular Structure & Function, The Hospital for Sick Children , Toronto, ON M5G 0A4, Canada.,Department of Biochemistry, University of Toronto , Toronto, ON M5S 1A8, Canada
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20
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Nostramo R, Herman PK. Deubiquitination and the regulation of stress granule assembly. Curr Genet 2016; 62:503-6. [PMID: 26852120 DOI: 10.1007/s00294-016-0571-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Revised: 01/25/2016] [Accepted: 01/28/2016] [Indexed: 12/31/2022]
Abstract
Stress granules (SGs) are evolutionarily conserved ribonucleoprotein (RNP) structures that form in response to a variety of environmental and cellular cues. The presence of these RNP granules has been linked to a number of human diseases, including neurodegenerative disorders like amyotrophic lateral sclerosis (ALS) and spinocerebellar ataxia type 2 (Li et al., J Cell Biol 201:361-372, 2013; Nonhoff et al., Mol Biol Cell 18:1385-1396, 2007). Understanding how the assembly of these granules is controlled could, therefore, suggest possible routes of therapy for patients afflicted with these conditions. Interestingly, several reports have identified a potential role for protein deubiquitination in the assembly of these RNP granules. In particular, recent work has found that a specific deubiquitinase enzyme, Ubp3, is required for efficient SG formation in S. cerevisiae (Nostramo et al., Mol Cell Biol 36:173-183, 2016). This same enzyme has been linked to SGs in other organisms, including humans and the fission yeast, Schizosaccharomyces pombe (Takahashi et al., Mol Cell Biol 33:815-829, 2013; Wang et al., RNA 18:694-703, 2012). At first glance, these observations suggest that a striking degree of conservation exists for a ubiquitin-based mechanism controlling SG assembly. However, the devil is truly in the details here, as the precise nature of the involvement of this deubiquitinating enzyme seems to vary in each organism. Here, we briefly review these differences and attempt to provide an overarching model for the role of ubiquitin in SG formation.
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Affiliation(s)
- R Nostramo
- Department of Molecular Genetics, The Ohio State University, Columbus, OH, 43210, USA
| | - P K Herman
- Department of Molecular Genetics, The Ohio State University, Columbus, OH, 43210, USA.
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21
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Nam MK, Han JH, Jang JY, Yun SE, Kim GY, Kang S, Rhim H. A novel link between the conformations, exposure of specific epitopes, and subcellular localization of α-synuclein. Biochim Biophys Acta Gen Subj 2015; 1850:2497-505. [PMID: 26391842 DOI: 10.1016/j.bbagen.2015.09.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2015] [Revised: 08/19/2015] [Accepted: 09/10/2015] [Indexed: 11/19/2022]
Abstract
BACKGROUND Genetic studies and the abundance of alpha-synuclein (α-Syn) in presynaptic terminals suggest that α-Syn plays a critical role in maintaining synaptic vesicle pools. However, there are still few experimental tools for elucidating its physiological roles. METHODS Unexpectedly, we detected various cellular distribution patterns of endogenous α-Syn by immunofluorescence assays (IFAs). To provide new molecular insights into α-Syn research, we identified associations between epitopes, conformations, and subcellular localization of α-Syn and categorized them. RESULTS The α-Syn exposing Y125 was found to coexist with F-actin at the edge of the cells, including the plasma membrane. α-Syn conformations exposing P128 or both F94 and K97 were partly localized to the mitochondria. These results indicate that various conformations of α-Syn are associated with specific subcellular localizations. Intriguingly, we demonstrate for the first time that the phosphorylated α-Syn at Ser129, also known as a Parkinson's disease (PD)-causing form, is targeted to the mitochondria. CONCLUSIONS Our study showed that different subcellular distribution patterns of α-Syn reflect the existence of various α-Syn conformations under normal conditions. GENERAL SIGNIFICANCE This study provides novel clues for deciphering the physiological function of α-Syn in connection with subcellular localization. Dissecting the specific α-Syn conformations may lead to useful strategies in PD therapy and diagnosis.
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Affiliation(s)
- Min-Kyung Nam
- Department of Biomedicine and Health Sciences, College of Medicine, The Catholic University of Korea, Seoul 137-701, Republic of Korea; Department of Medical Life Sciences, College of Medicine, The Catholic University of Korea, Seoul 137-701, Republic of Korea
| | - Ji-Hye Han
- Department of Biomedicine and Health Sciences, College of Medicine, The Catholic University of Korea, Seoul 137-701, Republic of Korea; Department of Medical Life Sciences, College of Medicine, The Catholic University of Korea, Seoul 137-701, Republic of Korea
| | - Ja-Young Jang
- Division of Life Sciences, College of Life Sciences and Biotechnology, Korea University, Seoul 136-701, Republic of Korea
| | - Si-Eun Yun
- Department of Biomedicine and Health Sciences, College of Medicine, The Catholic University of Korea, Seoul 137-701, Republic of Korea; Department of Medical Life Sciences, College of Medicine, The Catholic University of Korea, Seoul 137-701, Republic of Korea
| | - Goo-Young Kim
- Department of Biomedicine and Health Sciences, College of Medicine, The Catholic University of Korea, Seoul 137-701, Republic of Korea; Department of Medical Life Sciences, College of Medicine, The Catholic University of Korea, Seoul 137-701, Republic of Korea
| | - Seongman Kang
- Division of Life Sciences, College of Life Sciences and Biotechnology, Korea University, Seoul 136-701, Republic of Korea
| | - Hyangshuk Rhim
- Department of Biomedicine and Health Sciences, College of Medicine, The Catholic University of Korea, Seoul 137-701, Republic of Korea; Department of Medical Life Sciences, College of Medicine, The Catholic University of Korea, Seoul 137-701, Republic of Korea.
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22
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Alamo L, Li XE, Espinoza-Fonseca LM, Pinto A, Thomas DD, Lehman W, Padrón R. Tarantula myosin free head regulatory light chain phosphorylation stiffens N-terminal extension, releasing it and blocking its docking back. MOLECULAR BIOSYSTEMS 2015; 11:2180-9. [PMID: 26038302 PMCID: PMC4503497 DOI: 10.1039/c5mb00163c] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Molecular dynamics simulations of smooth and striated muscle myosin regulatory light chain (RLC) N-terminal extension (NTE) showed that diphosphorylation induces a disorder-to-order transition. Our goal here was to further explore the effects of mono- and diphosphorylation on the straightening and rigidification of the tarantula myosin RLC NTE. For that we used MD simulations followed by persistence length analysis to explore the consequences of secondary and tertiary structure changes occurring on RLC NTE following phosphorylation. Static and dynamic persistence length analysis of tarantula RLC NTE peptides suggest that diphosphorylation produces an important 24-fold straightening and a 16-fold rigidification of the RLC NTE, while monophosphorylation has a less profound effect. This new information on myosin structural mechanics, not fully revealed by previous EM and MD studies, add support to a cooperative phosphorylation-dependent activation mechanism as proposed for the tarantula thick filament. Our results suggest that the RLC NTE straightening and rigidification after Ser45 phosphorylation leads to a release of the constitutively Ser35 monophosphorylated free head swaying away from the thick filament shaft. This is so because the stiffened diphosphorylated RLC NTE would hinder the docking back of the free head after swaying away, becoming released and mobile and unable to recover its original interacting position on activation.
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Affiliation(s)
- Lorenzo Alamo
- Centro de Biología Estructural, Instituto Venezolano de Investigaciones Científicas (IVIC), Apdo. 20632, Caracas 1020, Venezuela.
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23
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Berlow RB, Dyson HJ, Wright PE. Functional advantages of dynamic protein disorder. FEBS Lett 2015; 589:2433-40. [PMID: 26073260 DOI: 10.1016/j.febslet.2015.06.003] [Citation(s) in RCA: 138] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2015] [Revised: 05/29/2015] [Accepted: 06/01/2015] [Indexed: 11/19/2022]
Abstract
Intrinsically disordered proteins participate in many important cellular regulatory processes. The absence of a well-defined structure in the free state of a disordered domain, and even on occasion when it is bound to physiological partners, is fundamental to its function. Disordered domains are frequently the location of multiple sites for post-translational modification, the key element of metabolic control in the cell. When a disordered domain folds upon binding to a partner, the resulting complex buries a far greater surface area than in an interaction of comparably-sized folded proteins, thus maximizing specificity at modest protein size. Disorder also maintains accessibility of sites for post-translational modification. Because of their inherent plasticity, disordered domains frequently adopt entirely different structures when bound to different partners, increasing the repertoire of available interactions without the necessity for expression of many different proteins. This feature also adds to the faithfulness of cellular regulation, as the availability of a given disordered domain depends on competition between various partners relevant to different cellular processes.
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Affiliation(s)
- Rebecca B Berlow
- Department of Integrative Structural and Computational Biology and Skaggs Institute of Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - 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, CA 92037, 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, CA 92037, USA.
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Espinoza-Fonseca LM, Colson BA, Thomas DD. Effects of pseudophosphorylation mutants on the structural dynamics of smooth muscle myosin regulatory light chain. MOLECULAR BIOSYSTEMS 2015; 10:2693-8. [PMID: 25091814 DOI: 10.1039/c4mb00364k] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We have performed 50 independent molecular dynamics (MD) simulations to determine the effect of pseudophosphorylation mutants on the structural dynamics of smooth muscle myosin (SMM) regulatory light chain (RLC). We previously showed that the N-terminal phosphorylation domain of RLC simultaneously populates two structural states in equilibrium, closed and open, and that phosphorylation at S19 induces a modest shift toward the open state, which is sufficient to activate smooth muscle. However, it remains unknown why pseudophosphorylation mutants poorly mimic phosphorylation-induced activation of SMM. We performed MD simulations of unphosphorylated, phosphorylated, and three pseudophosphorylated RLC mutants: S19E, T18D/S19D and T18E/S19E. We found that the S19E mutation does not shift the equilibrium toward the open state, indicating that simple charge replacement at position S19 does not mimic the activating effect of phosphorylation, providing a structural explanation for previously published functional data. In contrast, mutants T18D/S19D and T18E/S19E shift the equilibrium toward the open structure and partially activate in vitro motility, further supporting the model that an increase in the mol fraction of the open state is coupled to SMM motility. Structural analyses of the doubly-charged pseudophosphorylation mutants suggest that alterations in an interdomain salt bridge between residues R4 and D100 results in impaired signal transmission from RLC to the catalytic domain of SMM, which explains the low ATPase activity of these mutants. Our results demonstrate that phosphorylation produces a unique structural balance in the RLC. These observations have important implications for our understanding of the structural aspects of activation and force potentiation in smooth and striated muscle.
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Affiliation(s)
- L Michel Espinoza-Fonseca
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Jackson Hall 6-155, 321 Church St. SE, Minneapolis, MN 55455, USA.
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25
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Bah A, Vernon RM, Siddiqui Z, Krzeminski M, Muhandiram R, Zhao C, Sonenberg N, Kay LE, Forman-Kay JD. Folding of an intrinsically disordered protein by phosphorylation as a regulatory switch. Nature 2014; 519:106-9. [PMID: 25533957 DOI: 10.1038/nature13999] [Citation(s) in RCA: 399] [Impact Index Per Article: 39.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2014] [Accepted: 10/24/2014] [Indexed: 11/09/2022]
Abstract
Intrinsically disordered proteins play important roles in cell signalling, transcription, translation and cell cycle regulation. Although they lack stable tertiary structure, many intrinsically disordered proteins undergo disorder-to-order transitions upon binding to partners. Similarly, several folded proteins use regulated order-to-disorder transitions to mediate biological function. In principle, the function of intrinsically disordered proteins may be controlled by post-translational modifications that lead to structural changes such as folding, although this has not been observed. Here we show that multisite phosphorylation induces folding of the intrinsically disordered 4E-BP2, the major neural isoform of the family of three mammalian proteins that bind eIF4E and suppress cap-dependent translation initiation. In its non-phosphorylated state, 4E-BP2 interacts tightly with eIF4E using both a canonical YXXXXLΦ motif (starting at Y54) that undergoes a disorder-to-helix transition upon binding and a dynamic secondary binding site. We demonstrate that phosphorylation at T37 and T46 induces folding of residues P18-R62 of 4E-BP2 into a four-stranded β-domain that sequesters the helical YXXXXLΦ motif into a partly buried β-strand, blocking its accessibility to eIF4E. The folded state of pT37pT46 4E-BP2 is weakly stable, decreasing affinity by 100-fold and leading to an order-to-disorder transition upon binding to eIF4E, whereas fully phosphorylated 4E-BP2 is more stable, decreasing affinity by a factor of approximately 4,000. These results highlight stabilization of a phosphorylation-induced fold as the essential mechanism for phospho-regulation of the 4E-BP:eIF4E interaction and exemplify a new mode of biological regulation mediated by intrinsically disordered proteins.
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Affiliation(s)
- Alaji Bah
- 1] Molecular Structure and Function Program, Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada [2] Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Robert M Vernon
- 1] Molecular Structure and Function Program, Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada [2] Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Zeba Siddiqui
- Molecular Structure and Function Program, Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada
| | - Mickaël Krzeminski
- 1] Molecular Structure and Function Program, Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada [2] Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Ranjith Muhandiram
- 1] Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada [2] Department of Molecular Genetics, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Charlie Zhao
- Molecular Structure and Function Program, Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada
| | - Nahum Sonenberg
- Department of Biochemistry and Goodman Cancer Research Centre, McGill University, Montréal, Quebec H3G 1Y6, Canada
| | - Lewis E Kay
- 1] Molecular Structure and Function Program, Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada [2] Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada [3] Department of Molecular Genetics, University of Toronto, Toronto, Ontario M5S 1A8, Canada [4] Department of Chemistry, University of Toronto, Toronto, Ontario M5S 3H6, Canada
| | - Julie D Forman-Kay
- 1] Molecular Structure and Function Program, Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada [2] Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada
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26
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Radisavljevic Z. AKT as Locus of Cancer Phenotype. J Cell Biochem 2014; 116:1-5. [DOI: 10.1002/jcb.24947] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2014] [Accepted: 08/22/2014] [Indexed: 12/12/2022]
Affiliation(s)
- Ziv Radisavljevic
- Department of Surgery; Brigham and Women's Hospital; Harvard Medical School; Boston Massachusetts 02115
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27
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Nishi H, Shaytan A, Panchenko AR. Physicochemical mechanisms of protein regulation by phosphorylation. Front Genet 2014; 5:270. [PMID: 25147561 PMCID: PMC4124799 DOI: 10.3389/fgene.2014.00270] [Citation(s) in RCA: 132] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2014] [Accepted: 07/22/2014] [Indexed: 12/17/2022] Open
Abstract
Phosphorylation offers a dynamic way to regulate protein activity and subcellular localization, which is achieved through its reversibility and fast kinetics. Adding or removing a dianionic phosphate group somewhere on a protein often changes the protein’s structural properties, its stability and dynamics. Moreover, the majority of signaling pathways involve an extensive set of protein–protein interactions, and phosphorylation can be used to regulate and modulate protein–protein binding. Losses of phosphorylation sites, as a result of disease mutations, might disrupt protein binding and deregulate signal transduction. In this paper we focus on the effects of phosphorylation on protein stability, dynamics, and binding. We describe several physico-chemical mechanisms of protein regulation through phosphorylation and pay particular attention to phosphorylation in protein complexes and phosphorylation in the context of disorder–order and order–disorder transitions. Finally we assess the role of multiple phosphorylation sites in a protein molecule, their possible cooperativity and function.
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Affiliation(s)
- Hafumi Nishi
- Graduate School of Medical Life Science, Yokohama City University Yokohama Japan
| | - Alexey Shaytan
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health Bethesda, MD USA
| | - Anna R Panchenko
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health Bethesda, MD USA
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28
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Somavarapu AK, Balakrishnan S, Gautam AKS, Palmer DS, Venkatraman P. Structural interrogation of phosphoproteome identified by mass spectrometry reveals allowed and disallowed regions of phosphoconformation. BMC STRUCTURAL BIOLOGY 2014; 14:9. [PMID: 24618394 PMCID: PMC4007652 DOI: 10.1186/1472-6807-14-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/14/2013] [Accepted: 03/04/2014] [Indexed: 12/22/2022]
Abstract
Background High-throughput mass spectrometric (HT-MS) study is the method of choice for monitoring global changes in proteome. Data derived from these studies are meant for further validation and experimentation to discover novel biological insights. Here we evaluate use of relative solvent accessible surface area (rSASA) and DEPTH as indices to assess experimentally determined phosphorylation events deposited in PhosphoSitePlus. Results Based on accessibility, we map these identifications on allowed (accessible) or disallowed (inaccessible) regions of phosphoconformation. Surprisingly a striking number of HT-MS/MS derived events (1461/5947 sites or 24.6%) are present in the disallowed region of conformation. By considering protein dynamics, autophosphorylation events and/or the sequence specificity of kinases, 13.8% of these phosphosites can be moved to the allowed region of conformation. We also demonstrate that rSASA values can be used to increase the confidence of identification of phosphorylation sites within an ambiguous MS dataset. Conclusion While MS is a stand-alone technique for the identification of vast majority of phosphorylation events, identifications within disallowed region of conformation will benefit from techniques that independently probe for phosphorylation and protein dynamics. Our studies also imply that trapping alternate protein conformations may be a viable alternative to the design of inhibitors against mutation prone drug resistance kinases.
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Affiliation(s)
| | | | | | | | - Prasanna Venkatraman
- Protein Interactome Lab for Structural and Functional Biology, Advanced Center for Treatment Research and Education in Cancer, Tata Memorial Centre, Kharghar, Navi Mumbai, Maharashtra 410210, India.
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29
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Tinoco LW, Fraga JL, Anobom CD, Zolessi FR, Obal G, Toledo A, Pritsch O, Arruti C. Structural characterization of a neuroblast-specific phosphorylated region of MARCKS. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2014; 1844:837-49. [PMID: 24590112 DOI: 10.1016/j.bbapap.2014.02.016] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2013] [Revised: 02/07/2014] [Accepted: 02/20/2014] [Indexed: 11/19/2022]
Abstract
MARCKS (Myristoylated Alanine-Rich C Kinase substrate) is a natively unfolded protein that interacts with actin, Ca(2+)-Calmodulin, and some plasma membrane lipids. Such interactions occur at a highly conserved region that is specifically phosphorylated by PKC: the Effector Domain. There are two other conserved domains, MH1 (including a myristoylation site) and MH2, also located in the amino terminal region and whose structure and putative protein binding capabilities are currently unknown. MH2 sequence contains a serine that we described as being phosphorylated only in differentiating neurons (S25 in chick). Here, Circular Dichroism (CD) and Nuclear Magnetic Resonance (NMR) spectroscopy were used to characterize the phosphorylated and unphosphorylated forms of a peptide with the MARCKS sequence surrounding S25. The peptide phosphorylated at this residue is recognized by monoclonal antibody 3C3 (mAb 3C3). CD and NMR data indicated that S25 phosphorylation does not cause extensive modifications in the peptide structure. However, the sharper lines, the absence of multiple spin systems and relaxation dispersion data observed for the phosphorylated peptide suggested a more ordered structure. Surface Plasmon Resonance was employed to compare the binding properties of mAb 3C3 to MARCKS protein and peptide. SPR showed that mAb 3C3 binds to the whole protein and the peptide with a similar affinity, albeit different kinetics. The slightly ordered structure of the phosphorylated peptide might be at the origin of its ability to interact with mAb 3C3 antibody, but this binding did not noticeably modify the peptide structure.
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Affiliation(s)
- Luzineide W Tinoco
- Instituto de Pesquisas de Produtos Naturais, Universidade Federal do Rio de Janeiro, Cidade Universitária, CCS, Bloco H, Rio de Janeiro 21941-902, RJ, Brazil.
| | - Jully L Fraga
- Instituto de Pesquisas de Produtos Naturais, Universidade Federal do Rio de Janeiro, Cidade Universitária, CCS, Bloco H, Rio de Janeiro 21941-902, RJ, Brazil.
| | - Cristiane D Anobom
- Departamento de Bioquímica, Instituto de Química, Universidade Federal do Rio de Janeiro, Cidade Universitária, CT, Bloco A, Rio de Janeiro 21941-909, RJ, Brazil.
| | - Flavio R Zolessi
- Laboratorio de Cultivo de Tejidos, Sección Biología Celular, DBCM, Facultad de Ciencias, Universidad de la República, Iguá 4225, 11400 Montevideo, Uruguay.
| | - Gonzalo Obal
- Unidad de Biofísica de Proteínas, Institut Pasteur de Montevideo, Mataojo 2020, 11400 Montevideo, Uruguay.
| | - Andrea Toledo
- Laboratorio de Cultivo de Tejidos, Sección Biología Celular, DBCM, Facultad de Ciencias, Universidad de la República, Iguá 4225, 11400 Montevideo, Uruguay.
| | - Otto Pritsch
- Unidad de Biofísica de Proteínas, Institut Pasteur de Montevideo, Mataojo 2020, 11400 Montevideo, Uruguay.
| | - Cristina Arruti
- Laboratorio de Cultivo de Tejidos, Sección Biología Celular, DBCM, Facultad de Ciencias, Universidad de la República, Iguá 4225, 11400 Montevideo, Uruguay.
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Role of the essential light chain in the activation of smooth muscle myosin by regulatory light chain phosphorylation. J Struct Biol 2013; 185:375-82. [PMID: 24361582 DOI: 10.1016/j.jsb.2013.12.008] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2013] [Revised: 12/15/2013] [Accepted: 12/16/2013] [Indexed: 11/21/2022]
Abstract
The activity of smooth and non-muscle myosin II is regulated by phosphorylation of the regulatory light chain (RLC) at serine 19. The dephosphorylated state of full-length monomeric myosin is characterized by an asymmetric intramolecular head-head interaction that completely inhibits the ATPase activity, accompanied by a hairpin fold of the tail, which prevents filament assembly. Phosphorylation of serine 19 disrupts these head-head interactions by an unknown mechanism. Computational modeling (Tama et al., 2005. J. Mol. Biol. 345, 837-854) suggested that formation of the inhibited state is characterized by both torsional and bending motions about the myosin heavy chain (HC) at a location between the RLC and the essential light chain (ELC). Therefore, altering relative motions between the ELC and the RLC at this locus might disrupt the inhibited state. Based on this hypothesis we have derived an atomic model for the phosphorylated state of the smooth muscle myosin light chain domain (LCD). This model predicts a set of specific interactions between the N-terminal residues of the RLC with both the myosin HC and the ELC. Site directed mutagenesis was used to show that interactions between the phosphorylated N-terminus of the RLC and helix-A of the ELC are required for phosphorylation to activate smooth muscle myosin.
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31
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The conformational ensemble of the disordered and aggregation-protective 182–291 region of ataxin-3. Biochim Biophys Acta Gen Subj 2013; 1830:5236-47. [DOI: 10.1016/j.bbagen.2013.07.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2013] [Revised: 06/10/2013] [Accepted: 07/10/2013] [Indexed: 12/23/2022]
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Phosphorylation variation during the cell cycle scales with structural propensities of proteins. PLoS Comput Biol 2013; 9:e1002842. [PMID: 23326221 PMCID: PMC3542066 DOI: 10.1371/journal.pcbi.1002842] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2012] [Accepted: 11/02/2012] [Indexed: 11/19/2022] Open
Abstract
Phosphorylation at specific residues can activate a protein, lead to its localization to particular compartments, be a trigger for protein degradation and fulfill many other biological functions. Protein phosphorylation is increasingly being studied at a large scale and in a quantitative manner that includes a temporal dimension. By contrast, structural properties of identified phosphorylation sites have so far been investigated in a static, non-quantitative way. Here we combine for the first time dynamic properties of the phosphoproteome with protein structural features. At six time points of the cell division cycle we investigate how the variation of the amount of phosphorylation correlates with the protein structure in the vicinity of the modified site. We find two distinct phosphorylation site groups: intrinsically disordered regions tend to contain sites with dynamically varying levels, whereas regions with predominantly regular secondary structures retain more constant phosphorylation levels. The two groups show preferences for different amino acids in their kinase recognition motifs - proline and other disorder-associated residues are enriched in the former group and charged residues in the latter. Furthermore, these preferences scale with the degree of disorderedness, from regular to irregular and to disordered structures. Our results suggest that the structural organization of the region in which a phosphorylation site resides may serve as an additional control mechanism. They also imply that phosphorylation sites are associated with different time scales that serve different functional needs.
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Aan den Toorn M, Huijbers MME, de Vries SC, van Mierlo CPM. The Arabidopsis thaliana SERK1 kinase domain spontaneously refolds to an active state in vitro. PLoS One 2012; 7:e50907. [PMID: 23236403 PMCID: PMC3517577 DOI: 10.1371/journal.pone.0050907] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2012] [Accepted: 10/26/2012] [Indexed: 11/19/2022] Open
Abstract
Auto-phosphorylating kinase activity of plant leucine-rich-repeat receptor-like kinases (LRR-RLK's) needs to be under tight negative control to avoid unscheduled activation. One way to achieve this would be to keep these kinase domains as intrinsically disordered protein (IDP) during synthesis and transport to its final location. Subsequent folding, which may depend on chaperone activity or presence of interaction partners, is then required for full activation of the kinase domain. Bacterially produced SERK1 kinase domain was previously shown to be an active Ser/Thr kinase. SERK1 is predicted to contain a disordered region in kinase domains X and XI. Here, we show that loss of structure of the SERK1 kinase domain during unfolding is intimately linked to loss of activity. Phosphorylation of the SERK1 kinase domain neither changes its structure nor its stability. Unfolded SERK1 kinase has no autophosphorylation activity and upon removal of denaturant about one half of the protein population spontaneously refolds to an active protein in vitro. Thus, neither chaperones nor interaction partners are required during folding of this protein to its catalytically active state.
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Lambrughi M, Papaleo E, Testa L, Brocca S, De Gioia L, Grandori R. Intramolecular interactions stabilizing compact conformations of the intrinsically disordered kinase-inhibitor domain of Sic1: a molecular dynamics investigation. Front Physiol 2012. [PMID: 23189058 PMCID: PMC3504315 DOI: 10.3389/fphys.2012.00435] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Cyclin-dependent kinase inhibitors (CKIs) are key regulatory proteins of the eukaryotic cell cycle, which modulate cyclin-dependent kinase (Cdk) activity. CKIs perform their inhibitory effect by the formation of ternary complexes with a target kinase and its cognate cyclin. These regulators generally belong to the class of intrinsically disordered proteins (IDPs), which lack a well-defined and organized three-dimensional (3D) structure in their free state, undergoing folding upon binding to specific partners. Unbound IDPs are not merely random-coil structures, but can present intrinsically folded structural units (IFSUs) and collapsed conformations. These structural features can be relevant to protein function in vivo. The yeast CKI Sic1 is a 284-amino acid IDP that binds to Cdk1 in complex with the Clb5,6 cyclins, preventing phosphorylation of G1 substrates and, therefore, entrance to the S phase. Sic1 degradation, triggered by multiple phosphorylation events, promotes cell-cycle progression. Previous experimental studies pointed out a propensity of Sic1 and its isolated domains to populate both extended and compact conformations. The present contribution provides models for compact conformations of the Sic1 kinase-inhibitory domain (KID) by all-atom molecular dynamics (MD) simulations in explicit solvent and in the absence of interactors. The results are integrated by spectroscopic and spectrometric data. Helical IFSUs are identified, along with networks of intramolecular interactions. The results identify a group of putative hub residues and networks of electrostatic interactions, which are likely to be involved in the stabilization of the globular states.
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Affiliation(s)
- Matteo Lambrughi
- Department of Biotechnology and Biosciences, University of Milano-Bicocca Milan, Italy
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35
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Cardiac myosin binding protein-C restricts intrafilament torsional dynamics of actin in a phosphorylation-dependent manner. Proc Natl Acad Sci U S A 2012; 109:20437-42. [PMID: 23169656 DOI: 10.1073/pnas.1213027109] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
We have determined the effects of myosin binding protein-C (MyBP-C) and its domains on the microsecond rotational dynamics of actin, detected by time-resolved phosphorescence anisotropy (TPA). MyBP-C is a multidomain modulator of striated muscle contraction, interacting with myosin, titin, and possibly actin. Cardiac and slow skeletal MyBP-C are known substrates for protein kinase-A (PKA), and phosphorylation of the cardiac isoform alters contractile properties and myofilament structure. To determine the effects of MyBP-C on actin structural dynamics, we labeled actin at C374 with a phosphorescent dye and performed TPA experiments. The interaction of all three MyBP-C isoforms with actin increased the final anisotropy of the TPA decay, indicating restriction of the amplitude of actin torsional flexibility by 15-20° at saturation of the TPA effect. PKA phosphorylation of slow skeletal and cardiac MyBP-C relieved the restriction of torsional amplitude but also decreased the rate of torsional motion. In the case of fast skeletal MyBP-C, its effect on actin dynamics was unchanged by phosphorylation. The isolated C-terminal half of cardiac MyBP-C (C5-C10) had effects similar to those of the full-length protein, and it bound actin more tightly than the N-terminal half (C0-C4), which had smaller effects on actin dynamics that were independent of PKA phosphorylation. We propose that these MyBP-C-induced changes in actin dynamics play a role in the functional effects of MyBP-C on the actin-myosin interaction.
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36
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Colson BA, Gruber SJ, Thomas DD. Structural dynamics of muscle protein phosphorylation. J Muscle Res Cell Motil 2012; 33:419-29. [PMID: 22930331 DOI: 10.1007/s10974-012-9317-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2012] [Accepted: 08/07/2012] [Indexed: 02/03/2023]
Abstract
We have used site-directed spectroscopic probes to detect structural changes, motions, and interactions due to phosphorylation of proteins involved in the regulation of muscle contraction and relaxation. Protein crystal structures provide static snapshots that provide clues to the conformations that are sampled dynamically by proteins in the cellular environment. Our site-directed spectroscopic experiments, combined with computational simulations, extend these studies into functional assemblies in solution, and reveal details of protein regions that are too dynamic or disordered for crystallographic approaches. Here, we discuss phosphorylation-mediated structural transitions in the smooth muscle myosin regulatory light chain, the striated muscle accessory protein myosin binding protein-C, and the cardiac membrane Ca(2+) pump modulator phospholamban. In each of these systems, phosphorylation near the N terminus of the regulatory protein relieves an inhibitory interaction between the phosphoprotein and its regulatory target. Several additional unifying themes emerge from our studies: (a) The effect of phosphorylation is not to change the affinity of the phosphoprotein for its regulated binding partner, but to change the structure of the bound complex without dissociation. (b) Phosphorylation induces transitions between order and dynamic disorder. (c) Structural states are only loosely coupled to phosphorylation; i.e., complete phosphorylation induces dramatic functional effects with only a partial shift in the equilibrium between ordered and disordered structural states. These studies, which offer atomic-resolution insight into the structural and functional dynamics of these phosphoproteins, were inspired in part by the ground-breaking work in this field by Michael and Kate Barany.
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Affiliation(s)
- Brett A Colson
- Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA.
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37
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Arrigoni A, Grillo B, Vitriolo A, De Gioia L, Papaleo E. C-terminal acidic domain of ubiquitin-conjugating enzymes: A multi-functional conserved intrinsically disordered domain in family 3 of E2 enzymes. J Struct Biol 2012; 178:245-59. [DOI: 10.1016/j.jsb.2012.04.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2011] [Revised: 04/01/2012] [Accepted: 04/03/2012] [Indexed: 11/30/2022]
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Polyansky A, Zagrovic B. Protein Electrostatic Properties Predefining the Level of Surface Hydrophobicity Change upon Phosphorylation. J Phys Chem Lett 2012; 3:973-976. [PMID: 23914287 PMCID: PMC3726239 DOI: 10.1021/jz300103p] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2012] [Accepted: 03/22/2012] [Indexed: 06/02/2023]
Abstract
We use explicit-solvent, molecular dynamics simulations to study the change in polar properties of a solvent-accessible surface for proteins undergoing phosphorylation. We analyze eight different pairs of proteins representing different structural classes in native and phosphorylated states and estimate the polarity of their surface using the molecular hydrophobicity potential approach. Whereas the phosphorylation-induced hydrophobicity change in the vicinity of phosphosites does not vary strongly among the studied proteins, the equivalent change for complete proteins covers a surprisingly wide range of effects including even an increase in the overall hydrophobicity in some cases. Importantly, the observed changes are strongly related to electrostatic properties of proteins, such as the net charge per residue, the distribution of charged side-chain contacts, and the isoelectric point. These features predefine the level of surface hydrophobicity change upon phosphorylation and may thus contribute to the phosphorylation-induced alteration of the interactions between a protein and its environment.
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Affiliation(s)
- Anton
A. Polyansky
- Department of Structural and Computational Biology, Max F. Perutz Laboratories, University of Vienna, Campus Vienna Biocenter 5, Vienna AT-1030, Austria
- M.M. Shemyakin and Yu.A. Ovchinnikov Institute
of Bioorganic Chemistry, Russian Academy of Sciences, Moscow 117997, Russia
- Mediterranean Institute for Life Sciences, Split, Croatia
| | - Bojan Zagrovic
- Department of Structural and Computational Biology, Max F. Perutz Laboratories, University of Vienna, Campus Vienna Biocenter 5, Vienna AT-1030, Austria
- Mediterranean Institute for Life Sciences, Split, Croatia
- Department of Physics, Faculty of Science, University of Split, Split, Croatia
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39
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Crystal structure of a phosphorylated light chain domain of scallop smooth-muscle myosin. Biophys J 2011; 101:2185-9. [PMID: 22067157 PMCID: PMC3207169 DOI: 10.1016/j.bpj.2011.09.028] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2011] [Revised: 09/01/2011] [Accepted: 09/06/2011] [Indexed: 01/07/2023] Open
Abstract
We have determined the crystal structure of a phosphorylated smooth-muscle myosin light chain domain (LCD). This reconstituted LCD is of a sea scallop catch muscle myosin with its phosphorylatable regulatory light chain (RLC SmoA). In the crystal structure, Arg(16), an arginine residue that is present in this isoform but not in vertebrate smooth-muscle RLC, stabilizes the phosphorylation site. This arginine interacts with the carbonyl group of the phosphorylation-site serine in the unphosphorylated LCD (determined previously), and with the phosphate group when the serine is phosphorylated. However, the overall conformation of the LCD is essentially unchanged upon phosphorylation. This result provides additional evidence that phosphorylation of the RLC is unlikely to act as an on-switch in regulation of scallop catch muscle myosin.
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Jung HS, Billington N, Thirumurugan K, Salzameda B, Cremo CR, Chalovich JM, Chantler PD, Knight PJ. Role of the tail in the regulated state of myosin 2. J Mol Biol 2011; 408:863-78. [PMID: 21419133 DOI: 10.1016/j.jmb.2011.03.019] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2010] [Revised: 03/08/2011] [Accepted: 03/09/2011] [Indexed: 11/30/2022]
Abstract
Myosin 2 from vertebrate smooth muscle or non-muscle sources is in equilibrium between compact, inactive monomers and thick filaments under physiological conditions. In the inactive monomer, the two heads pack compactly together, and the long tail is folded into three closely packed segments that are associated chiefly with one of the heads. The molecular basis of the folding of the tail remains unexplained. By using electron microscopy, we show that compact monomers of smooth muscle myosin 2 have the same structure in both the native state and following specific, intramolecular photo-cross-linking between Cys109 of the regulatory light chain (RLC) and segment 3 of the tail. Nonspecific cross-linking between lysine residues of the folded monomer by glutaraldehyde also does not perturb the compact conformation and stabilizes it against unfolding at high ionic strength. Sequence comparisons across phyla and myosin 2 isoforms suggest that the folding of the tail is stabilized by ionic interactions between the positively charged N-terminal sequence of the RLC and a negatively charged region near the start of tail segment 3 and that phosphorylation of the RLC could perturb these interactions. Our results support the view that interactions between the heads and the distal tail perform a critical role in regulating activity of myosin 2 molecules through stabilizing the compact monomer conformation.
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Affiliation(s)
- Hyun Suk Jung
- Institute of Molecular and Cellular Biology and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, LS2 9JT, UK
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41
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Kengyel A, Wolf WA, Chisholm RL, Sellers JR. Nonmuscle myosin IIA with a GFP fused to the N-terminus of the regulatory light chain is regulated normally. J Muscle Res Cell Motil 2010; 31:163-70. [PMID: 20711642 PMCID: PMC3786345 DOI: 10.1007/s10974-010-9220-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2010] [Accepted: 07/08/2010] [Indexed: 10/19/2022]
Abstract
Nonmuscle myosin II plays a crucial role in a variety of cellular processes (e.g., polarity formation, cell motility, and cytokinesis). It is composed of two heavy chains, two regulatory light chains and two essential light chains. The ATPase activity of the myosin II motor domain is regulated through phosphorylation of the regulatory light chain (RLC) by myosin light chain kinase. To study myosin function and localization in cellular processes, GFP-fused RLCs are widely used; however, the exact kinetic properties of myosins with bound GFP-RLC are poorly described. More importantly, it has not been shown that a regulatory light chain fused at its N-terminus with GFP can maintain the normal phosphorylation-dependent regulation of nonmuscle myosin or serve as a substrate for myosin light chain kinase. We coexpressed N-terminal GFP-RLC with a heavy meromyosin (HMM)-like fragment of nonmuscle myosin IIA and essential light chain to characterize the phosphorylation dynamics and in vitro kinetic properties of the resulting HMM. Myosin light chain kinase phosphorylates the GFP-RLC bound to HMM IIA with the same V(max) as it does the wild type RLC bound to HMM IIA, but the K(m) is about two fold higher for the GFP fusion protein, meaning that it is a somewhat poorer substrate. The steady-state actin-activated MgATPase activity of the GFP-RLC HMM is very low in the absence of phosphorylation demonstrating that the GFP moiety does not prevent formation of the off state. The actin-activated MgATPase activity of phosphorylated GFP-RLC-HMM and is about half that of wild type phosphorylated HMM. The ability of phosphorylated GFP-RLC-HMM to move actin filaments in the actin gliding assay is also slightly compromised. These data indicate that despite some kinetic differences the N-terminal GFP fusion to the regulatory light chain is a reasonable model system for studying myosin function in vivo.
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Affiliation(s)
- Andras Kengyel
- Laboratory of Molecular Physiology, National Heart, Lung and Blood Institute, National Institutes of Health, Building 50, Room 3523, Bethesda, MD 20892, USA. Department of Biophysics, Faculty of Medicine, University of Pécs, Pécs, Hungary
| | - Wendy A. Wolf
- Center for Genetic Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Rex L. Chisholm
- Center for Genetic Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - James R. Sellers
- Laboratory of Molecular Physiology, National Heart, Lung and Blood Institute, National Institutes of Health, Building 50, Room 3523, Bethesda, MD 20892, USA
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42
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Zoete V, Irving MB, Michielin O. MM-GBSA binding free energy decomposition and T cell receptor engineering. J Mol Recognit 2010; 23:142-52. [PMID: 20151417 DOI: 10.1002/jmr.1005] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Recognition by the T-cell receptor (TCR) of immunogenic peptides (p) presented by class I major histocompatibility complexes (MHC) is the key event in the immune response against virus infected cells or tumor cells. The major determinant of T cell activation is the affinity of the TCR for the peptide-MHC complex, though kinetic parameters are also important. A study of the 2C TCR/SIYR/H-2Kb system using a binding free energy decomposition (BFED) based on the MM-GBSA approach had been performed to assess the performance of the approach on this system. The results showed that the TCR-p-MHC BFED including entropic terms provides a detailed and reliable description of the energetics of the interaction (Zoete and Michielin, 2007). Based on these results, we have developed a new approach to design sequence modifications for a TCR recognizing the human leukocyte antigen (HLA)-A2 restricted tumor epitope NY-ESO-1. NY-ESO-1 is a cancer testis antigen expressed not only in melanoma, but also on several other types of cancers. It has been observed at high frequencies in melanoma patients with unusually positive clinical outcome and, therefore, represents an interesting target for adoptive transfer with modified TCR. Sequence modifications of TCR potentially increasing the affinity for this epitope have been proposed and tested in vitro. T cells expressing some of the proposed TCR mutants showed better T cell functionality, with improved killing of peptide-loaded T2 cells and better proliferative capacity compared to the wild type TCR expressing cells. These results open the door of rational TCR design for adoptive transfer cancer therapy.
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Affiliation(s)
- V Zoete
- Swiss Institute of Bioinformatics, Quartier Sorge-Batiment Genopode, CH-1015 Lausanne Switzerland
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43
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Phosphorylation-induced structural changes in smooth muscle myosin regulatory light chain. Proc Natl Acad Sci U S A 2010; 107:8207-12. [PMID: 20404208 DOI: 10.1073/pnas.1001941107] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
We have performed complementary time-resolved fluorescence resonance energy transfer (TR-FRET) experiments and molecular dynamics (MD) simulations to elucidate structural changes in the phosphorylation domain (PD) of smooth muscle regulatory light chain (RLC) bound to myosin. PD is absent in crystal structures, leaving uncertainty about the mechanism of regulation. Donor-acceptor pairs of probes were attached to three site-directed di-Cys mutants of RLC, each having one Cys at position 129 in the C-terminal lobe and the other at position 2, 3, or 7 in the N-terminal PD. Labeled RLC was reconstituted onto myosin subfragment 1 (S1). TR-FRET resolved two simultaneously populated structural states of RLC, closed and open, in both unphosphorylated and phosphorylated biochemical states. All three FRET pairs show that phosphorylation shifts the equilibrium toward the open state, increasing its mol fraction by approximately 20%. MD simulations agree with experiments in remarkable detail, confirming the coexistence of two structural states, with phosphorylation shifting the system toward the more dynamic open structural state. This agreement between experiment and simulation validates the additional structural details provided by MD simulations: In the closed state, PD is bent onto the surface of the C-terminal lobe, stabilized by interdomain salt bridges. In the open state, PD is more helical and straight, resides farther from the C-terminal lobe, and is stabilized by an intradomain salt bridge. The result is a vivid atomic-resolution visualization of the first step in the molecular mechanism by which phosphorylation activates smooth muscle.
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Vacic V, Iakoucheva LM, Lonardi S, Radivojac P. Graphlet kernels for prediction of functional residues in protein structures. J Comput Biol 2010; 17:55-72. [PMID: 20078397 DOI: 10.1089/cmb.2009.0029] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
We introduce a novel graph-based kernel method for annotating functional residues in protein structures. A structure is first modeled as a protein contact graph, where nodes correspond to residues and edges connect spatially neighboring residues. Each vertex in the graph is then represented as a vector of counts of labeled non-isomorphic subgraphs (graphlets), centered on the vertex of interest. A similarity measure between two vertices is expressed as the inner product of their respective count vectors and is used in a supervised learning framework to classify protein residues. We evaluated our method on two function prediction problems: identification of catalytic residues in proteins, which is a well-studied problem suitable for benchmarking, and a much less explored problem of predicting phosphorylation sites in protein structures. The performance of the graphlet kernel approach was then compared against two alternative methods, a sequence-based predictor and our implementation of the FEATURE framework. On both tasks, the graphlet kernel performed favorably; however, the margin of difference was considerably higher on the problem of phosphorylation site prediction. While there is data that phosphorylation sites are preferentially positioned in intrinsically disordered regions, we provide evidence that for the sites that are located in structured regions, neither the surface accessibility alone nor the averaged measures calculated from the residue microenvironments utilized by FEATURE were sufficient to achieve high accuracy. The key benefit of the graphlet representation is its ability to capture neighborhood similarities in protein structures via enumerating the patterns of local connectivity in the corresponding labeled graphs.
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Affiliation(s)
- Vladimir Vacic
- Department of Computer Science and Engineering, University of California, Riverside, California, USA
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45
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Cimas A, Gaigeot MP. DFT-MD and vibrational anharmonicities of a phosphorylated amino acid. Success and failure. Phys Chem Chem Phys 2010; 12:3501-10. [DOI: 10.1039/b924025j] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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46
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Himmel DM, Mui S, O'Neall-Hennessey E, Szent-Györgyi AG, Cohen C. The on-off switch in regulated myosins: different triggers but related mechanisms. J Mol Biol 2009; 394:496-505. [PMID: 19769984 PMCID: PMC2997636 DOI: 10.1016/j.jmb.2009.09.035] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2009] [Revised: 09/14/2009] [Accepted: 09/15/2009] [Indexed: 01/07/2023]
Abstract
In regulated myosin, motor and enzymatic activities are toggled between the on-state and off-state by a switch located on its lever arm domain, here called the regulatory domain (RD). This region consists of a long alpha-helical "heavy chain" stabilized by a "regulatory" light chain (RLC) and an "essential" light chain (ELC). The on-state is activated by phosphorylation of the RLC of vertebrate smooth muscle RD or by direct binding of Ca(2+) to the ELC of molluscan RD. Crystal structures are available only for the molluscan RD. To understand in more detail the pathway between the on-state and the off-state, we have now also determined the crystal structure of a molluscan (scallop) RD in the absence of Ca(2+). Our results indicate that loss of Ca(2+) abolishes most of the interactions between the light chains and may increase the flexibility of the RD heavy chain. We propose that disruption of critical links with the C-lobe of the RLC is the key event initiating the off-state in both smooth muscle myosins and molluscan myosins.
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Affiliation(s)
- Daniel M. Himmel
- Rosenstiel Basic Medical Sciences Research Center, Biology Department, Brandeis University, Waltham, Massachusetts 02453-2728, U.S.A.,Corresponding authors: C. Cohen, , Phone: (781) 736-2446, FAX: (781) 736-2419, D. M. Himmel, , Phone: 732-235-4498, FAX: 732-235-5788
| | - Suet Mui
- Rosenstiel Basic Medical Sciences Research Center, Biology Department, Brandeis University, Waltham, Massachusetts 02453-2728, U.S.A
| | - Elizabeth O'Neall-Hennessey
- Rosenstiel Basic Medical Sciences Research Center, Biology Department, Brandeis University, Waltham, Massachusetts 02453-2728, U.S.A
| | - Andrew G. Szent-Györgyi
- Rosenstiel Basic Medical Sciences Research Center, Biology Department, Brandeis University, Waltham, Massachusetts 02453-2728, U.S.A
| | - Carolyn Cohen
- Rosenstiel Basic Medical Sciences Research Center, Biology Department, Brandeis University, Waltham, Massachusetts 02453-2728, U.S.A.,Corresponding authors: C. Cohen, , Phone: (781) 736-2446, FAX: (781) 736-2419, D. M. Himmel, , Phone: 732-235-4498, FAX: 732-235-5788
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Cimas A, Maitre P, Ohanessian G, Gaigeot MP. Molecular Dynamics and Room Temperature Vibrational Properties of Deprotonated Phosphorylated Serine. J Chem Theory Comput 2009; 5:2388-400. [DOI: 10.1021/ct900179d] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- A. Cimas
- Laboratoire Analyse et Modélisation pour la Biologie et l’Environnement, UMR8587 CNRS, Université d’Evry val d’Essonne, boulevard F. Mitterrand, Bat. Maupertuis, 91025 Evry Cedex, France, Laboratoire de Chimie Physique, Université Paris Sud 11, UMR8000 CNRS, Faculté des sciences, bâtiment 350, 91405 Orsay Cedex, France, and Laboratoire des Mécanismes réactionnels, Département de Chimie, Ecole Polytechnique, CNRS, 91128 Palaiseau Cedex, France
| | - P. Maitre
- Laboratoire Analyse et Modélisation pour la Biologie et l’Environnement, UMR8587 CNRS, Université d’Evry val d’Essonne, boulevard F. Mitterrand, Bat. Maupertuis, 91025 Evry Cedex, France, Laboratoire de Chimie Physique, Université Paris Sud 11, UMR8000 CNRS, Faculté des sciences, bâtiment 350, 91405 Orsay Cedex, France, and Laboratoire des Mécanismes réactionnels, Département de Chimie, Ecole Polytechnique, CNRS, 91128 Palaiseau Cedex, France
| | - G. Ohanessian
- Laboratoire Analyse et Modélisation pour la Biologie et l’Environnement, UMR8587 CNRS, Université d’Evry val d’Essonne, boulevard F. Mitterrand, Bat. Maupertuis, 91025 Evry Cedex, France, Laboratoire de Chimie Physique, Université Paris Sud 11, UMR8000 CNRS, Faculté des sciences, bâtiment 350, 91405 Orsay Cedex, France, and Laboratoire des Mécanismes réactionnels, Département de Chimie, Ecole Polytechnique, CNRS, 91128 Palaiseau Cedex, France
| | - M.-P. Gaigeot
- Laboratoire Analyse et Modélisation pour la Biologie et l’Environnement, UMR8587 CNRS, Université d’Evry val d’Essonne, boulevard F. Mitterrand, Bat. Maupertuis, 91025 Evry Cedex, France, Laboratoire de Chimie Physique, Université Paris Sud 11, UMR8000 CNRS, Faculté des sciences, bâtiment 350, 91405 Orsay Cedex, France, and Laboratoire des Mécanismes réactionnels, Département de Chimie, Ecole Polytechnique, CNRS, 91128 Palaiseau Cedex, France
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Thomas DD, Kast D, Korman VL. Site-directed spectroscopic probes of actomyosin structural dynamics. Annu Rev Biophys 2009; 38:347-69. [PMID: 19416073 DOI: 10.1146/annurev.biophys.35.040405.102118] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Spectroscopy of myosin and actin has entered a golden age. High-resolution crystal structures of isolated actin and myosin have been used to construct detailed models for the dynamic actomyosin interactions that move muscle. Improved protein mutagenesis and expression technologies have facilitated site-directed labeling with fluorescent and spin probes. Spectroscopic instrumentation has achieved impressive advances in sensitivity and resolution. Here we highlight the contributions of site-directed spectroscopic probes to understanding the structural dynamics of myosin II and its actin complexes in solution and muscle fibers. We emphasize studies that probe directly the movements of structural elements within the myosin catalytic and light-chain domains, and changes in the dynamics of both actin and myosin due to their alternating strong and weak interactions in the ATPase cycle. A moving picture emerges in which single biochemical states produce multiple structural states, and transitions between states of order and dynamic disorder power the actomyosin engine.
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Affiliation(s)
- David D Thomas
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA.
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49
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Narayanan A, Jacobson MP. Computational studies of protein regulation by post-translational phosphorylation. Curr Opin Struct Biol 2009; 19:156-63. [DOI: 10.1016/j.sbi.2009.02.007] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2008] [Revised: 02/20/2009] [Accepted: 02/24/2009] [Indexed: 02/08/2023]
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50
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Leucine‐rich hydrophobic clusters promote folding of the N‐terminus of the intrinsically disordered transactivation domain of p53. FEBS Lett 2009; 583:556-60. [DOI: 10.1016/j.febslet.2008.12.060] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2008] [Revised: 12/08/2008] [Accepted: 12/24/2008] [Indexed: 11/18/2022]
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