1
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Erguven M, Kilic S, Karaca E, Diril MK. Genetic complementation screening and molecular docking give new insight on phosphorylation-dependent Mastl kinase activation. J Biomol Struct Dyn 2023; 41:8241-8253. [PMID: 36270968 DOI: 10.1080/07391102.2022.2131627] [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: 08/26/2022] [Accepted: 09/26/2022] [Indexed: 10/24/2022]
Abstract
Mastl is a mitotic kinase that is essential for error-free chromosome segregation. It is an atypical member of AGC kinase family, possessing a unique non-conserved middle region. The mechanism of Mastl activation has been studied extensively in vitro. Phosphorylation of several residues were identified to be crucial for activation. These sites correspond to T193 and T206 in the activation loop and S861 in the C-terminal tail of mouse Mastl. To date, the significance of these phosphosites was not confirmed in intact mammalian cells. Here, we utilize a genetic complementation approach to determine the essentials of mammalian Mastl kinase activation. We used tamoxifen-inducible conditional knockout mouse embryonic fibroblasts to delete endogenous Mastl and screened various mutants for their ability to complement its loss. S861A mutant was able to complement endogenous Mastl loss. In parallel, we performed computational molecular docking studies to evaluate the significance of this residue for kinase activation. Our in-depth sequence and structure analysis revealed that Mastl pS861 does not belong to a conformational state, where the phosphoresidue contributes to C-tail docking. C-tail of Mastl is relatively short and it lacks a hydrophobic (HF) motif that would otherwise help its anchoring over N-lobe, required for the final steps of kinase activation. Our results show that phosphorylation of Mastl C-tail turn motif (S861) is dispensable for kinase function in cellulo.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Mehmet Erguven
- Izmir Biomedicine and Genome Center, Izmir, Turkey
- Izmir International Biomedicine and Genome Institute, Dokuz Eylul University, Izmir, Turkey
| | - Seval Kilic
- Izmir Biomedicine and Genome Center, Izmir, Turkey
- Izmir International Biomedicine and Genome Institute, Dokuz Eylul University, Izmir, Turkey
| | - Ezgi Karaca
- Izmir Biomedicine and Genome Center, Izmir, Turkey
- Izmir International Biomedicine and Genome Institute, Dokuz Eylul University, Izmir, Turkey
| | - M Kasim Diril
- Izmir Biomedicine and Genome Center, Izmir, Turkey
- Izmir International Biomedicine and Genome Institute, Dokuz Eylul University, Izmir, Turkey
- Department of Medical Biology, Faculty of Medicine, Dokuz Eylul University, Izmir, Turkey
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2
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Gratteri C, Ambrosio FA, Lupia A, Moraca F, Catalanotti B, Costa G, Bellocchi M, Carioti L, Salpini R, Ceccherini-Silberstein F, Frazia SL, Malagnino V, Sarmati L, Svicher V, Bryant S, Artese A, Alcaro S. Molecular and Structural Aspects of Clinically Relevant Mutations of SARS-CoV-2 RNA-Dependent RNA Polymerase in Remdesivir-Treated Patients. Pharmaceuticals (Basel) 2023; 16:1143. [PMID: 37631058 PMCID: PMC10459223 DOI: 10.3390/ph16081143] [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: 07/13/2023] [Revised: 08/01/2023] [Accepted: 08/07/2023] [Indexed: 08/27/2023] Open
Abstract
(1) Background: SARS-CoV-2 RNA-dependent RNA polymerase (RdRp) is a promising therapeutic target to fight COVID-19, and many RdRp inhibitors nucleotide/nucleoside analogs, such as remdesivir, have been identified or are in clinical studies. However, the appearance of resistant mutations could reduce their efficacy. In the present work, we structurally evaluated the impact of RdRp mutations found at baseline in 39 patients treated with remdesivir and associated with a different degree of antiviral response in vivo. (2) Methods: A refined bioinformatics approach was applied to assign SARS-CoV-2 clade and lineage, and to define RdRp mutational profiles. In line with such a method, the same mutations were built and analyzed by combining docking and thermodynamics evaluations with both molecular dynamics and representative pharmacophore models. (3) Results: Clinical studies revealed that patients bearing the most prevalent triple mutant P323L+671S+M899I, which was present in 41% of patients, or the more complex mutational profile P323L+G671S+L838I+D738Y+K91E, which was found with a prevalence of 2.6%, showed a delayed reduced response to remdesivir, as confirmed by the increase in SARS-CoV-2 viral load and by a reduced theoretical binding affinity versus RdRp (ΔGbindWT = -122.70 kcal/mol; ΔGbindP323L+671S+M899I = -84.78 kcal/mol; ΔGbindP323L+G671S+L838I+D738Y+K91E = -96.74 kcal/mol). Combined computational approaches helped to rationalize such clinical observations, offering a mechanistic understanding of the allosteric effects of mutants on the global motions of the viral RNA synthesis machine and in the changes of the interactions patterns of remdesivir during its binding.
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Affiliation(s)
- Carmen Gratteri
- Dipartimento di Scienze della Salute, Campus “S. Venuta”, Università degli Studi “Magna Græcia” di Catanzaro, Viale Europa, 88100 Catanzaro, Italy; (C.G.); (G.C.); (S.A.)
| | - Francesca Alessandra Ambrosio
- Dipartimento di Medicina Sperimentale e Clinica, Campus “S. Venuta”, Università degli Studi “Magna Græcia” di Catanzaro, Viale Europa, 88100 Catanzaro, Italy;
| | - Antonio Lupia
- Dipartimento di Scienze della vita e dell’ambiente, Università degli Studi di Cagliari, Cittadella Universitaria di Monserrato, 09124 Cagliari, Italy;
- Net4Science S.r.l., Università degli Studi “Magna Græcia” di Catanzaro, 88100 Catanzaro, Italy
| | - Federica Moraca
- Net4Science S.r.l., Università degli Studi “Magna Græcia” di Catanzaro, 88100 Catanzaro, Italy
- Dipartimento di Farmacia, Università degli Studi di Napoli “Federico II”, Via D. Montesano 49, 80131 Napoli, Italy;
| | - Bruno Catalanotti
- Dipartimento di Farmacia, Università degli Studi di Napoli “Federico II”, Via D. Montesano 49, 80131 Napoli, Italy;
| | - Giosuè Costa
- Dipartimento di Scienze della Salute, Campus “S. Venuta”, Università degli Studi “Magna Græcia” di Catanzaro, Viale Europa, 88100 Catanzaro, Italy; (C.G.); (G.C.); (S.A.)
- Net4Science S.r.l., Università degli Studi “Magna Græcia” di Catanzaro, 88100 Catanzaro, Italy
| | - Maria Bellocchi
- Dipartimento di Medicina Sperimentale, Università Tor Vergata di Roma, Via Montpellier, 1, 00133 Roma, Italy; (M.B.); (L.C.); (R.S.); (F.C.-S.)
| | - Luca Carioti
- Dipartimento di Medicina Sperimentale, Università Tor Vergata di Roma, Via Montpellier, 1, 00133 Roma, Italy; (M.B.); (L.C.); (R.S.); (F.C.-S.)
| | - Romina Salpini
- Dipartimento di Medicina Sperimentale, Università Tor Vergata di Roma, Via Montpellier, 1, 00133 Roma, Italy; (M.B.); (L.C.); (R.S.); (F.C.-S.)
| | - Francesca Ceccherini-Silberstein
- Dipartimento di Medicina Sperimentale, Università Tor Vergata di Roma, Via Montpellier, 1, 00133 Roma, Italy; (M.B.); (L.C.); (R.S.); (F.C.-S.)
| | - Simone La Frazia
- Dipartimento di Biologia, Università Tor Vergata di Roma, Via della Ricerca Scientifica, 1, 00133 Roma, Italy; (S.L.F.); (V.S.)
| | - Vincenzo Malagnino
- Dipartimento di Medicina dei Sistemi, Università Tor Vergata di Roma, Via Montpellier, 1, 00133 Roma, Italy; (V.M.); (L.S.)
| | - Loredana Sarmati
- Dipartimento di Medicina dei Sistemi, Università Tor Vergata di Roma, Via Montpellier, 1, 00133 Roma, Italy; (V.M.); (L.S.)
| | - Valentina Svicher
- Dipartimento di Biologia, Università Tor Vergata di Roma, Via della Ricerca Scientifica, 1, 00133 Roma, Italy; (S.L.F.); (V.S.)
| | - Sharon Bryant
- Inte:Ligand GmbH, Mariahilferstrasse 74B/11, 1070 Vienna, Austria;
| | - Anna Artese
- Dipartimento di Scienze della Salute, Campus “S. Venuta”, Università degli Studi “Magna Græcia” di Catanzaro, Viale Europa, 88100 Catanzaro, Italy; (C.G.); (G.C.); (S.A.)
- Net4Science S.r.l., Università degli Studi “Magna Græcia” di Catanzaro, 88100 Catanzaro, Italy
| | - Stefano Alcaro
- Dipartimento di Scienze della Salute, Campus “S. Venuta”, Università degli Studi “Magna Græcia” di Catanzaro, Viale Europa, 88100 Catanzaro, Italy; (C.G.); (G.C.); (S.A.)
- Net4Science S.r.l., Università degli Studi “Magna Græcia” di Catanzaro, 88100 Catanzaro, Italy
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3
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Nicolaou ST, Kannan S, Warwicker J, Verma CS. Activation of p53: How phosphorylated Ser15 triggers sequential phosphorylation of p53 at Thr18 by CK1δ. Proteins 2022; 90:2009-2022. [PMID: 35752942 PMCID: PMC9796392 DOI: 10.1002/prot.26393] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Revised: 06/10/2022] [Accepted: 06/21/2022] [Indexed: 01/01/2023]
Abstract
The N-terminal transactivation domain (TAD) of p53 is a disordered region with multiple phosphorylation sites. Phosphorylation at Thr18 is crucial for the release of p53 from its negative regulator, MDM2. In stressed cells, CK1δ is responsible for phosphorylating Thr18, but requires Ser15 to be phosphorylated. To understand the mechanistic underpinnings of this sequential phosphorylation, molecular modeling and molecular dynamics simulation studies of these phosphorylation events were carried out. Our models suggest that a positively charged region on CK1δ near the adenosine triphosphate (ATP) binding pocket, which is conserved across species, sequesters the negatively charged pSer15, thereby constraining the positioning of the rest of the peptide, such that the side chain of Thr18 is positioned close to the γ-phosphate of ATP. Furthermore, our studies show that the phosphorylated p53 TAD1 (p53pSer15) peptide binds more strongly to CK1δ than does p53. p53 adopts a helical structure when bound to CK1δ, which is lost upon phosphorylation at Ser15, thus gaining higher flexibility and ability to morph into the binding site. We propose that upon phosphorylation at Ser15 the p53 TAD1 peptide binds to CK1δ through an electrostatically driven induced fit mechanism resulting in a flanking fuzzy complex.
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Affiliation(s)
- Sonia T. Nicolaou
- Faculty of Biology, Medicine and Health, School of Biological SciencesManchester Institute of Biotechnology, University of ManchesterManchesterUK,Bioinformatics Institute, Agency for Science, Technology, and Research (A*STAR)SingaporeSingapore
| | - Srinivasaraghavan Kannan
- Bioinformatics Institute, Agency for Science, Technology, and Research (A*STAR)SingaporeSingapore
| | - Jim Warwicker
- Faculty of Biology, Medicine and Health, School of Biological SciencesManchester Institute of Biotechnology, University of ManchesterManchesterUK
| | - Chandra S. Verma
- Bioinformatics Institute, Agency for Science, Technology, and Research (A*STAR)SingaporeSingapore,School of Biological SciencesNanyang Technological UniversitySingaporeSingapore,Department of Biological SciencesNational University of SingaporeSingaporeSingapore
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4
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Weaver TM, Washington MT, Freudenthal BD. New insights into DNA polymerase mechanisms provided by time-lapse crystallography. Curr Opin Struct Biol 2022; 77:102465. [PMID: 36174287 PMCID: PMC9772199 DOI: 10.1016/j.sbi.2022.102465] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Revised: 08/15/2022] [Accepted: 08/24/2022] [Indexed: 12/24/2022]
Abstract
DNA polymerases play central roles in DNA replication and repair by catalyzing template-directed nucleotide incorporation. Recently time-lapse X-ray crystallography, which allows one to observe reaction intermediates, has revealed numerous and unexpected mechanistic features of DNA polymerases. In this article, we will examine recent new discoveries that have come from time-lapse crystallography that are currently transforming our understanding of the structural mechanisms used by DNA polymerases. Among these new discoveries are the binding of a third metal ion within the polymerase active site, the mechanisms of translocation along the DNA, the presence of new fidelity checkpoints, a novel pyrophosphatase activity within the active site, and the mechanisms of pyrophosphorolysis.
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Affiliation(s)
- Tyler M Weaver
- Department of Biochemistry and Molecular Biology, Department of Cancer Biology, University of Kansas Medical Center, Kansas City, KS, 66160, USA. https://twitter.com/tylermweaver1
| | - M Todd Washington
- Department of Biochemistry, University of Iowa, Iowa City, IA 52242, USA.
| | - Bret D Freudenthal
- Department of Biochemistry and Molecular Biology, Department of Cancer Biology, University of Kansas Medical Center, Kansas City, KS, 66160, USA.
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5
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Shumilov AV, Gotovtsev PM. Modeling the activity of the dopamine signaling pathway by combination of analog electrical circuit and mathematical approaches. Heliyon 2021; 7:e05879. [PMID: 33553717 PMCID: PMC7855338 DOI: 10.1016/j.heliyon.2020.e05879] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Revised: 12/22/2019] [Accepted: 12/24/2020] [Indexed: 11/24/2022] Open
Abstract
This paper demonstrates the application of the system biology principles on the example of the dopamine signaling pathway in neurons. Presented model is based on two approaches - cytomorphic electronic circuits and mathematical modeling. Transcription and phosphorylation of DARPP-32 was modeled by analog circuit, based on well-known approaches presented in [1]. It was shown that application of circuit helps to receive signal oscillations that close to described ones in real biological systems. This combination on the one hand gives possibility to simplify calculations, on another to show this signaling pathway dynamics. The expected effect of changes in the functioning of calcium channels is considered, and the mathematical model of the interaction of system components is proposed. The average frequency of calcium current oscillations due to the presence of dopamine was 30 Hz in presented model, that is consistent with the literature, where the frequency of such oscillations is up to several tens of Hz. All presented results shows good correlation with known data, which already published today.
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Affiliation(s)
- A V Shumilov
- National Research Centre "Kurchatov Institute", Biotechnology and Bioenergy Department, Russia.,Skolkovo Institute of Science and Technology, Informational Science and Technology, Russia
| | - P M Gotovtsev
- National Research Centre "Kurchatov Institute", Biotechnology and Bioenergy Department, Russia.,Moscow Institute of Physics and Technology, Dolgoprudny, Moscow Region, Russia
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6
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Arya R, Kumari S, Pandey B, Mistry H, Bihani SC, Das A, Prashar V, Gupta GD, Panicker L, Kumar M. Structural insights into SARS-CoV-2 proteins. J Mol Biol 2021; 433:166725. [PMID: 33245961 PMCID: PMC7685130 DOI: 10.1016/j.jmb.2020.11.024] [Citation(s) in RCA: 198] [Impact Index Per Article: 66.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Revised: 11/19/2020] [Accepted: 11/19/2020] [Indexed: 01/18/2023]
Abstract
The unprecedented scale of the ongoing COVID-19 pandemic has catalyzed an intense effort of the global scientific community to unravel different aspects of the disease in a short time. One of the crucial aspects of these developments is the determination of more than three hundred experimental structures of SARS-CoV-2 proteins in the last few months. These include structures of viral non-structural, structural, and accessory proteins and their complexes determined by either X-ray diffraction or cryo-electron microscopy. These structures elucidate the intricate working of different components of the viral machinery at the atomic level during different steps of the viral life cycle, including attachment to the host cell, viral genome replication and transcription, and genome packaging and assembly of the virion. Some of these proteins are also potential targets for drug development against the disease. In this review, we discuss important structural features of different SARS-CoV-2 proteins with their function, and their potential as a target for therapeutic interventions.
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Affiliation(s)
- Rimanshee Arya
- Protein Crystallography Section, Radiation Biology & Health Sciences Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085, India
| | - Shweta Kumari
- Protein Crystallography Section, Radiation Biology & Health Sciences Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085, India
| | - Bharati Pandey
- Protein Crystallography Section, Radiation Biology & Health Sciences Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085, India
| | - Hiral Mistry
- Protein Crystallography Section, Radiation Biology & Health Sciences Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085, India; Homi Bhabha National Institute, Anushaktinagar, Mumbai 400094, India
| | - Subhash C Bihani
- Protein Crystallography Section, Radiation Biology & Health Sciences Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085, India
| | - Amit Das
- Protein Crystallography Section, Radiation Biology & Health Sciences Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085, India
| | - Vishal Prashar
- Protein Crystallography Section, Radiation Biology & Health Sciences Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085, India
| | - Gagan D Gupta
- Protein Crystallography Section, Radiation Biology & Health Sciences Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085, India; Homi Bhabha National Institute, Anushaktinagar, Mumbai 400094, India
| | - Lata Panicker
- Protein Crystallography Section, Radiation Biology & Health Sciences Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085, India
| | - Mukesh Kumar
- Protein Crystallography Section, Radiation Biology & Health Sciences Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085, India; Homi Bhabha National Institute, Anushaktinagar, Mumbai 400094, India.
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7
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Teh AH, Yeap KH, Hisano T. Insights into DEPTOR regulation from in silico analysis of DEPTOR complexes. J Struct Biol 2020; 212:107602. [PMID: 32798656 DOI: 10.1016/j.jsb.2020.107602] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Revised: 07/21/2020] [Accepted: 08/11/2020] [Indexed: 01/25/2023]
Abstract
DEPTOR is an inhibitor of the mTOR kinase which controls cell growth. DEPTOR consists of two DEP domains and a PDZ domain connected by an unstructured linker, and its stability is tightly regulated through post-translational modifications of its linker region that contains the 286SSGYFS291 degron. Based on the mTORC1 complex, our modelling suggests a possible spatial arrangement of DEPTOR which is characterised to form a dimer. Our model shows that the two PDZ domains of a DEPTOR dimer bind separately to the dimeric mTOR's FAT domains ~130 Å apart, while each of the two extended linkers is sufficiently long to span from the FAT domain to the kinase domain of mTOR and beyond to join a shared dimer of the DEP domains. This places the linker's S299 closest to the kinase's catalytic site, indicating that phosphorylation would start with it and successively upstream towards DEPTOR's degron. The CK1α kinase is reportedly responsible for the phosphorylation of the degron, and our docking analysis further reveals that CK1α contains sites to bind DEPTOR's pS286, pS287 and pT295, which may act as priming phosphates for the phosphorylation of the degron's S291. DEPTOR's linker can also be ubiquitylated by the UbcH5A-SCFβ-TrCP complex without its PDZ dissociating from mTOR according to the modelling. As the catalytic cleft of mTOR's kinase is restricted, interactions between the kinase's unstructured segment surrounding the cleft and DEPTOR's linker, which may involve S293 and S299, may be critical to controlling DEPTOR's access to the catalytic cleft and hence its phosphorylation by mTOR in a manner dependent on mTOR's activation.
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Affiliation(s)
- Aik-Hong Teh
- Centre for Chemical Biology, Universiti Sains Malaysia, 10 Persiaran Bukit Jambul, 11900 Penang, Malaysia; USM-RIKEN International Centre for Ageing Science (URICAS), Universiti Sains Malaysia, 11800 Penang, Malaysia.
| | - Kean-Heng Yeap
- Centre for Chemical Biology, Universiti Sains Malaysia, 10 Persiaran Bukit Jambul, 11900 Penang, Malaysia; USM-RIKEN International Centre for Ageing Science (URICAS), Universiti Sains Malaysia, 11800 Penang, Malaysia
| | - Tamao Hisano
- USM-RIKEN International Centre for Ageing Science (URICAS), Universiti Sains Malaysia, 11800 Penang, Malaysia; Laboratory for Protein Functional and Structural Biology, RIKEN Center for Biosystems Dynamics Research, Yokohama, Kanagawa 230-0045, Japan
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8
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Srivastava R, Akash, Parida AP, Chauhan PK, Kumar R. Identification, structure analysis, and transcript profiling of purple acid phosphatases under Pi deficiency in tomato (Solanum lycopersicum L.) and its wild relatives. Int J Biol Macromol 2020; 165:2253-2266. [PMID: 33098900 DOI: 10.1016/j.ijbiomac.2020.10.080] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Revised: 09/12/2020] [Accepted: 10/11/2020] [Indexed: 11/26/2022]
Abstract
Purple acid phosphatases (PAPs), a family of metallo-phosphoesterase enzymes, are involved in phosphorus nutrition in plants. In this study, we report that the tomato genome encodes 25 PAP members. Physio-biochemical analyses revealed relatively lower total root-associated acid phosphatase activity in the seedlings of Solanum pimpinellifolium than their cultivated tomato seedlings under Pi deficiency. Scrutiny of their transcript abundance shows that most of PAPs are activated, although to varying levels, under Pi deficiency in tomato. Further investigation demonstrates that the magnitude of induction of phosphate starvation inducible root-associated PAP homologs remains lower in the Pi-starved S. pimpinellifolium seedlings, hence, accounting for the lower acid phosphatase activity in this wild relative. Examination of their amino acid sequences revealed significant variation in their substrate-specificity defining residues. Among all members, only SlPAP15 possesses the critical lysine residue (R337) and atypical REKA motif in its C-terminal region. Homology modeling and docking studies revealed that ADP and ATP are preferred substrates of SlPAP15. We also identified other amino acid residues present in the vicinity of the active site, possibly facilitating such physical interactions. Altogether, the results presented here will help in the functional characterization of these genes in the tomato in the future.
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Affiliation(s)
- Rajat Srivastava
- PTRL, Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Hyderabad 500046, India
| | - Akash
- PTRL, Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Hyderabad 500046, India
| | - Adwaita Prasad Parida
- Department of Plant Molecular Biology, University of Delhi South Campus, New Delhi 110021, India
| | - Pankaj Kumar Chauhan
- PTRL, Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Hyderabad 500046, India
| | - Rahul Kumar
- PTRL, Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Hyderabad 500046, India.
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9
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Speltz EB, Zalatan JG. The Relationship between Effective Molarity and Affinity Governs Rate Enhancements in Tethered Kinase-Substrate Reactions. Biochemistry 2020; 59:2182-2193. [PMID: 32433869 PMCID: PMC7328773 DOI: 10.1021/acs.biochem.0c00205] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Scaffold proteins are thought to accelerate protein phosphorylation reactions by tethering kinases and substrates together, but there is little quantitative data on their functional effects. To assess the contribution of tethering to kinase reactivity, we compared intramolecular and intermolecular kinase reactions in a minimal model system. We found that tethering can enhance reaction rates in a flexible tethered kinase system and that the magnitude of the effect is sensitive to the structure of the tether. The largest effective molarity we obtained was ∼0.08 μM, which is much lower than the effects observed in small molecule model systems and other tethered protein reactions. We further demonstrated that the tethered intramolecular reaction only makes a significant contribution to the observed rates when the scaffolded complex assembles at concentrations below the effective molarity. These findings provide a quantitative framework that can be applied to understand endogenous protein scaffolds and engineer synthetic networks.
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Affiliation(s)
| | - Jesse G. Zalatan
- Department of Chemistry, University of Washington, Seattle, WA 98195
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10
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Tressler CM, Zondlo NJ. Perfluoro- tert-Butyl Hydroxyprolines as Sensitive, Conformationally Responsive Molecular Probes: Detection of Protein Kinase Activity by 19F NMR. ACS Chem Biol 2020; 15:1096-1103. [PMID: 32125821 DOI: 10.1021/acschembio.0c00131] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
19F NMR spectroscopy provides the ability to quantitatively analyze single species in complex solutions but is often limited by the modest sensitivity inherent to NMR. 4R- and 4S-Perfluoro-tert-buyl hydroxyproline contain 9 equivalent fluorines, in amino acids with strong conformational preferences. In order to test the ability to use these amino acids as sensitive probes of protein modifications, the perfluoro-tert-buyl hydroxyprolines were incorporated into substrate peptides of the protein kinases PKA and Akt. Peptides containing each diastereomeric proline were rapidly phosphorylated by each protein kinase and exhibited 19F chemical shift changes as a result of phosphorylation. The sensitivity of the perfluoro-tert-butyl group allowed quantitative analysis of the kinetics of phosphorylation over three half-lives at single-digit micromolar concentrations of each species. The distinct conformational preferences of these amino acids allowed the optimization of the substrate with a conformationally matched amino acid, in order to maximize the rate of phosphorylation. PKA preferred the 4R-amino acid at the -1 position, whereas the closely related AGC kinase Akt preferred the 4S-amino acid. These data, combined with analysis of structures of the Michaelis complexes of these kinases in the PDB, suggest that PKA recognizes the PPII conformation at the P-1 position relative to the phosphorylation site, while Akt/PKB recognizes an extended conformation at this position. These results suggest that conformational targeting may be employed to increase specificity in recognition by protein kinases. Perfluoro-tert-butyl hydroxyprolines were applied to the real-time detection and quantification of PKA activity and inhibition of PKA activity in HeLa cell extracts via 19F NMR spectroscopy. The coupling of proline ring pucker with main chain conformation suggests broad application of perfluoro-tert-butyl hydroxyprolines in molecular sensing and imaging.
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Affiliation(s)
- Caitlin M. Tressler
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, United States
| | - Neal J. Zondlo
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, United States
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11
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Solorza J, Recabarren R, Alzate-Morales J. Molecular Insights into the Trapping Effect of Ca 2+ in Protein Kinase A: A Molecular Dynamics Study. J Chem Inf Model 2020; 60:898-914. [PMID: 31804819 DOI: 10.1021/acs.jcim.9b00857] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Protein kinase A has become a model system for the study of kinases, and therefore, a comprehensive understanding of the underlying molecular mechanisms in its catalytic cycle is of crucial importance. One of the aspects that has received recent attention is the role that metal cofactors play in the catalytic cycle. Although Mg2+ is the well-known physiological ion used by protein kinases, Ca2+ ions can also assist the phosphoryl transfer reaction but with lower catalytic activities. This inhibitory effect has been attributed to the ability of Ca2+ to trap the reaction products at the active site, and it has been proposed as a possible regulatory mechanism of the enzyme. Thus, in order to get a clearer understanding of these molecular events, computational simulations in the product state of PKA, in the presence of Mg2+ and Ca2+ ions, were performed through molecular dynamics (MD). Different protonation states of the active site were considered in order to model the different mechanistic pathways that have been proposed. Our results show that different protonation states of the phosphorylated serine residue at the peptide substrate (pSer21), as well as the protonation state of residue Asp166, can have a marked influence on the flexibility of regions surrounding the active site. This is the case of the glycine-rich loop, a structural motif that is directly involved in the release of the products from the PKA active site. MD simulations were capable to reproduce the crystallographic conformations but also showed other conformations not previously reported in the crystal structures that may be involved in enhancing the affinity of pSP20 to PKA in the presence of Ca2+. Hydrogen bonding interactions at the PKA-pSP20 interface were influenced whether by the protonation state of the active site or by the metal cofactor used by the enzyme. Altogether, our results provide molecular aspects into the inhibitory mechanism of Ca2+ in PKA and suggest which is the most probable protonation state of the phosphorylated product at the active site.
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Affiliation(s)
- Jocelyn Solorza
- Centro de Bioinformática, Simulación y Modelado (CBSM), Facultad de Ingeniería , Universidad de Talca , 1 Poniente 1141 , Talca , Chile
| | - Rodrigo Recabarren
- Centro de Bioinformática, Simulación y Modelado (CBSM), Facultad de Ingeniería , Universidad de Talca , 1 Poniente 1141 , Talca , Chile
| | - Jans Alzate-Morales
- Centro de Bioinformática, Simulación y Modelado (CBSM), Facultad de Ingeniería , Universidad de Talca , 1 Poniente 1141 , Talca , Chile
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Cryo-EM Structure of Nucleotide-Bound Tel1 ATM Unravels the Molecular Basis of Inhibition and Structural Rationale for Disease-Associated Mutations. Structure 2019; 28:96-104.e3. [PMID: 31740029 PMCID: PMC6945111 DOI: 10.1016/j.str.2019.10.012] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Revised: 09/05/2019] [Accepted: 10/18/2019] [Indexed: 01/20/2023]
Abstract
Yeast Tel1 and its highly conserved human ortholog ataxia-telangiectasia mutated (ATM) are large protein kinases central to the maintenance of genome integrity. Mutations in ATM are found in ataxia-telangiectasia (A-T) patients and ATM is one of the most frequently mutated genes in many cancers. Using cryoelectron microscopy, we present the structure of Tel1 in a nucleotide-bound state. Our structure reveals molecular details of key residues surrounding the nucleotide binding site and provides a structural and molecular basis for its intrinsically low basal activity. We show that the catalytic residues are in a productive conformation for catalysis, but the phosphatidylinositol 3-kinase-related kinase (PIKK) regulatory domain insert restricts peptide substrate access and the N-lobe is in an open conformation, thus explaining the requirement for Tel1 activation. Structural comparisons with other PIKKs suggest a conserved and common allosteric activation mechanism. Our work also provides a structural rationale for many mutations found in A-T and cancer.
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Menger FM, Nome F. Interaction vs Preorganization in Enzyme Catalysis. A Dispute That Calls for Resolution. ACS Chem Biol 2019; 14:1386-1392. [PMID: 31150194 DOI: 10.1021/acschembio.8b01029] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
This essay focuses on the debate between Warshel et al. (proponents of preorganization) and Menger and Nome (proponents of spatiotemporal effects) over the source of fast enzyme catalysis. The Warshel model proposes that the main function of enzymes is to push the solvent coordinate toward the transition state. Other physical-organic factors (e.g., desolvation, entropic effects, ground state destabilization, etc.) do not, ostensibly, contribute substantially to the rate. Indeed, physical organic chemistry in its entirety was claimed to be "irrelevant to an enzyme's active site". Preorganization had been applied by Warshel to his "flagship" enzyme, ketosteroid isomerase, but we discuss troubling issues with their ensuing analysis. For example, the concepts of "general acid" and "general base", known to play a role in this enzyme's mechanism, are ignored in the text. In contrast, the spatiotemporal theory postulates that enzyme-like rates (i.e., accelerations >108) occur when two functionalities are held rigidly at contact distances less than ca. 3 Å. Numerous diverse organic systems are shown to bear this out experimentally. Many of these are intramolecular systems where distances between functionalities are known. Among them are fast intramolecular systems where strain is actually generated during the reaction, thereby excluding steric compression as a source of the observed enzyme-like rates. Finally, the account ends with structural data from four active sites of enzymes, obtained by others, all showing contact distances between substrate analogues and enzyme. To our knowledge, contact distances less than the diameter of water are found universally among enzymes, and it is to this fact that we attribute their extremely fast rates given the assumption that enzymes, whatever their particular mechanism, obey elementary chemical principles.
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Affiliation(s)
- Fredric M. Menger
- Department of Chemistry, Emory University, Atlanta, Georgia 30322, United States
| | - Faruk Nome
- Departamento de Química, Universidade Federal de Santa Catarina, Florianópolis, SC 88040-900 Brazil
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Mayo CB, Erlandsen H, Mouser DJ, Feinstein AG, Robinson VL, May ER, Cole JL. Structural Basis of Protein Kinase R Autophosphorylation. Biochemistry 2019; 58:2967-2977. [PMID: 31246429 DOI: 10.1021/acs.biochem.9b00161] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The RNA-activated protein kinase, PKR, is a key mediator of the innate immunity response to viral infection. Viral double-stranded RNAs induce PKR dimerization and autophosphorylation. The PKR kinase domain forms a back-to-back dimer. However, intermolecular ( trans) autophosphorylation is not feasible in this arrangement. We have obtained PKR kinase structures that resolves this dilemma. The kinase protomers interact via the known back-to-back interface as well as a front-to-front interface that is formed by exchange of activation segments. Mutational analysis of the front-to-front interface support a functional role in PKR activation. Molecular dynamics simulations reveal that the activation segment is highly dynamic in the front-to-front dimer and can adopt conformations conducive to phosphoryl transfer. We propose a mechanism where back-to-back dimerization induces a conformational change that activates PKR to phosphorylate a "substrate" kinase docked in a front-to-front geometry. This mechanism may be relevant to related kinases that phosphorylate the eukaryotic initiation factor eIF2α.
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15
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Weng G, Wang E, Chen F, Sun H, Wang Z, Hou T. Assessing the performance of MM/PBSA and MM/GBSA methods. 9. Prediction reliability of binding affinities and binding poses for protein-peptide complexes. Phys Chem Chem Phys 2019; 21:10135-10145. [PMID: 31062799 DOI: 10.1039/c9cp01674k] [Citation(s) in RCA: 83] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
A significant number of protein-protein interactions (PPIs) are mediated through the interactions between proteins and peptide segments, and therefore determination of protein-peptide interactions (PpIs) is critical to gain an in-depth understanding of the PPI network and even design peptides or small molecules capable of modulating PPIs. Computational approaches, especially molecular docking, provide an efficient way to model PpIs, and a reliable scoring function that can recognize the correct binding conformations for protein-peptide complexes is one of the most important components in protein-peptide docking. The end-point binding free energy calculation methods, such as MM/GBSA and MM/PBSA, are theoretically more rigorous than most empirical and semi-empirical scoring functions designed for protein-peptide docking, but their performance in predicting binding affinities and binding poses for protein-peptide systems has not been systematically assessed. In this study, we first evaluated the capability of MM/GBSA and MM/PBSA with different solvation models, interior dielectric constants (εin) and force fields to predict the binding affinities for 53 protein-peptide complexes. For the 19 short peptides with 5-12 residues, MM/PBSA based on the minimized structures in explicit solvent with the ff99 force field and εin = 2 yields the best correlation between the predicted binding affinities and the experimental data (rp = 0.748), while for the 34 medium-size peptides with 20-25 residues, MM/GBSA based on 1 ns of molecular dynamics (MD) simulations in implicit solvent with the ff03 force field, the GBOBC1 model and a low interior dielectric constant (εin = 1) yields the best accuracy (rp = 0.735). Then, we assessed the rescoring capability of MM/PBSA and MM/GBSA to distinguish the correct binding conformations from the decoys for 112 protein-peptide systems. The results illustrate that MM/PBSA based on the minimized structures with the ff99 or ff14SB force field and MM/GBSA based on the minimized structures with the ff03 force field show excellent capability to recognize the near-native binding poses for the short and medium-size peptides, respectively, and they outperform the predictions given by two popular protein-peptide docking algorithms (pepATTRACT and HPEPDOCK). Therefore, MM/PBSA and MM/GBSA are powerful tools to predict the binding affinities and identify the correct binding poses for protein-peptide systems.
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Affiliation(s)
- Gaoqi Weng
- College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, China.
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Wang Y, V S M, Kim J, Li G, Ahuja LG, Aoto P, Taylor SS, Veglia G. Globally correlated conformational entropy underlies positive and negative cooperativity in a kinase's enzymatic cycle. Nat Commun 2019; 10:799. [PMID: 30778078 PMCID: PMC6379427 DOI: 10.1038/s41467-019-08655-7] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2018] [Accepted: 01/15/2019] [Indexed: 11/16/2022] Open
Abstract
Enzymes accelerate the rate of chemical transformations by reducing the activation barriers of uncatalyzed reactions. For signaling enzymes, substrate recognition, binding, and product release are often rate-determining steps in which enthalpy-entropy compensation plays a crucial role. While the nature of enthalpic interactions can be inferred from structural data, the molecular origin and role of entropy in enzyme catalysis remains poorly understood. Using thermocalorimetry, NMR, and MD simulations, we studied the conformational landscape of the catalytic subunit of cAMP-dependent protein kinase A, a ubiquitous phosphoryl transferase involved in a myriad of cellular processes. Along the enzymatic cycle, the kinase exhibits positive and negative cooperativity for substrate and nucleotide binding and product release. We found that globally coordinated changes of conformational entropy activated by ligand binding, together with synchronous and asynchronous breathing motions of the enzyme, underlie allosteric cooperativity along the kinase's cycle.
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Affiliation(s)
- Yingjie Wang
- Department of Chemistry, University of Minnesota, Minneapolis, MN, 55455, USA
- Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Manu V S
- Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Jonggul Kim
- Department of Chemistry, University of Minnesota, Minneapolis, MN, 55455, USA
- Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN, 55455, USA
- Department of Biophysics and Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Geoffrey Li
- Department of Chemistry, University of Minnesota, Minneapolis, MN, 55455, USA
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN, 37240, USA
| | - Lalima G Ahuja
- Department of Chemistry and Biochemistry, and Pharmacology University of California at San Diego, La Jolla, CA, 92093, USA
| | - Philip Aoto
- Department of Chemistry and Biochemistry, and Pharmacology University of California at San Diego, La Jolla, CA, 92093, USA
| | - Susan S Taylor
- Department of Chemistry and Biochemistry, and Pharmacology University of California at San Diego, La Jolla, CA, 92093, USA
| | - Gianluigi Veglia
- Department of Chemistry, University of Minnesota, Minneapolis, MN, 55455, USA.
- Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN, 55455, USA.
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Water-mediated conformational preselection mechanism in substrate binding cooperativity to protein kinase A. Proc Natl Acad Sci U S A 2018; 115:3852-3857. [PMID: 29581285 DOI: 10.1073/pnas.1720024115] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Substrate binding cooperativity in protein kinase A (PKA) seems to involve allosteric coupling between the two binding sites. It received significant attention, but its molecular basis still remains not entirely clear. Based on long molecular dynamics of PKA and its complexes, we characterized an allosteric pathway that links ATP binding to the redistribution of states adopted by a protein substrate positioning segment in favor of those that warrant correct binding. We demonstrate that the cooperativity mechanism critically depends on the presence of water in two distinct, buried hydration sites. One holds just a single water molecule, which acts as a switchable hydrogen bond bridge along the allosteric pathway. The second, filled with partially disordered solvent, is essential for providing a smooth free energy landscape underlying conformational transitions of the peptide binding region. Our findings remain in agreement with experimental data, also concerning the cooperativity abolishing effect of the Y204A mutation, and indicate a plausible molecular mechanism contributing to experimentally observed binding cooperativity of the two substrates.
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