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Gran-Scheuch A, Hanreich S, Keizer I, W Harteveld J, Ruijter E, Drienovská I. Designing Michaelases: exploration of novel protein scaffolds for iminium biocatalysis. Faraday Discuss 2024. [PMID: 38842386 DOI: 10.1039/d4fd00057a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2024]
Abstract
Biocatalysis is becoming a powerful and sustainable alternative for asymmetric catalysis. However, enzymes are often restricted to metabolic and less complex reactivities. This can be addressed by protein engineering, such as incorporating new-to-nature functional groups into proteins through the so-called expansion of the genetic code to produce artificial enzymes. Selecting a suitable protein scaffold is a challenging task that plays a key role in designing artificial enzymes. In this work, we explored different protein scaffolds for an abiological model of iminium-ion catalysis, Michael addition of nitromethane into E-cinnamaldehyde. We studied scaffolds looking for open hydrophobic pockets and enzymes with described binding sites for the targeted substrate. The proteins were expressed and variants harboring functional amine groups - lysine, p-aminophenylalanine, or N6-(D-prolyl)-L-lysine - were analyzed for the model reaction. Among the newly identified scaffolds, a thermophilic ene-reductase from Thermoanaerobacter pseudethanolicus was shown to be the most promising biomolecular scaffold for this reaction.
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Affiliation(s)
- Alejandro Gran-Scheuch
- Department of Chemistry and Pharmaceutical Sciences, Faculty of Science, Vrije Universiteit Amsterdam, De Boelelaan 1108, 1081 HZ, Amsterdam, The Netherlands.
| | - Stefanie Hanreich
- Department of Chemistry and Pharmaceutical Sciences, Faculty of Science, Vrije Universiteit Amsterdam, De Boelelaan 1108, 1081 HZ, Amsterdam, The Netherlands.
| | - Iris Keizer
- Department of Chemistry and Pharmaceutical Sciences, Faculty of Science, Vrije Universiteit Amsterdam, De Boelelaan 1108, 1081 HZ, Amsterdam, The Netherlands.
| | - Jaap W Harteveld
- Department of Chemistry and Pharmaceutical Sciences, Faculty of Science, Vrije Universiteit Amsterdam, De Boelelaan 1108, 1081 HZ, Amsterdam, The Netherlands.
| | - Eelco Ruijter
- Department of Chemistry and Pharmaceutical Sciences, Faculty of Science, Vrije Universiteit Amsterdam, De Boelelaan 1108, 1081 HZ, Amsterdam, The Netherlands.
| | - Ivana Drienovská
- Department of Chemistry and Pharmaceutical Sciences, Faculty of Science, Vrije Universiteit Amsterdam, De Boelelaan 1108, 1081 HZ, Amsterdam, The Netherlands.
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2
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Heydenreich FM, Marti-Solano M, Sandhu M, Kobilka BK, Bouvier M, Babu MM. Molecular determinants of ligand efficacy and potency in GPCR signaling. Science 2023; 382:eadh1859. [PMID: 38127743 PMCID: PMC7615523 DOI: 10.1126/science.adh1859] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Accepted: 11/07/2023] [Indexed: 12/23/2023]
Abstract
Heterotrimeric guanine nucleotide-binding protein (G protein)-coupled receptors (GPCRs) bind to extracellular ligands and drugs and modulate intracellular responses through conformational changes. Despite their importance as drug targets, the molecular origins of pharmacological properties such as efficacy (maximum signaling response) and potency (the ligand concentration at half-maximal response) remain poorly understood for any ligand-receptor-signaling system. We used the prototypical adrenaline-β2 adrenergic receptor-G protein system to reveal how specific receptor residues decode and translate the information encoded in a ligand to mediate a signaling response. We present a data science framework to integrate pharmacological and structural data to uncover structural changes and allosteric networks relevant for ligand pharmacology. These methods can be tailored to study any ligand-receptor-signaling system, and the principles open possibilities for designing orthosteric and allosteric compounds with defined signaling properties.
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Affiliation(s)
- Franziska M. Heydenreich
- Department of Molecular and Cellular Physiology, Stanford University
School of Medicine, Stanford, CA, USA
- MRC Laboratory of Molecular Biology, Cambridge, UK
- Department of Biochemistry and Molecular Medicine, Institute for
Research in Immunology and Cancer, Université de Montréal, Montreal,
QC, Canada
| | - Maria Marti-Solano
- MRC Laboratory of Molecular Biology, Cambridge, UK
- Department of Pharmacology, University of Cambridge, Cambridge,
UK
| | - Manbir Sandhu
- Department of Pharmacology, University of Cambridge, Cambridge,
UK
| | - Brian K. Kobilka
- Department of Molecular and Cellular Physiology, Stanford University
School of Medicine, Stanford, CA, USA
| | - Michel Bouvier
- Department of Biochemistry and Molecular Medicine, Institute for
Research in Immunology and Cancer, Université de Montréal, Montreal,
QC, Canada
| | - M. Madan Babu
- MRC Laboratory of Molecular Biology, Cambridge, UK
- Department of Structural Biology and Center of Excellence for
Data-Driven Discovery, St. Jude Children’s Research Hospital, Memphis, TN,
USA
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3
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Barbosa C, Rodrigues CF, Lončar N, Martins LO, Todorovic S, Silveira CM. Spectroelectrochemistry for determination of the redox potential in heme enzymes: Dye-decolorizing peroxidases. BBA ADVANCES 2023; 5:100112. [PMID: 38235374 PMCID: PMC10792693 DOI: 10.1016/j.bbadva.2023.100112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Revised: 12/19/2023] [Accepted: 12/20/2023] [Indexed: 01/19/2024] Open
Abstract
Dye-decolorizing peroxidases (DyPs) are heme-containing enzymes that are structurally unrelated to other peroxidases. Some DyPs show high potential for applications in biotechnology, which critically depends on the stability and redox potential (E°') of the enzyme. Here we provide a comparative analysis of UV-Vis- and surface-enhanced resonance Raman-based spectroelectrochemical methods for determination of the E°' of DyPs from two different organisms, and their variants generated targeting E°' upshift. We show that substituting the highly conserved Arginine in the distal side of the heme pocket by hydrophobic amino acid residues impacts the heme architecture and redox potential of DyPs from the two organisms in a very distinct manner. We demonstrate the advantages and drawbacks of the used spectroelectrochemical approaches, which is relevant for other heme proteins that contain multiple heme centers or spin populations.
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Affiliation(s)
- Catarina Barbosa
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade NOVA de Lisboa, Av. da República, Oeiras 2780-157, Portugal
| | - Carolina F. Rodrigues
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade NOVA de Lisboa, Av. da República, Oeiras 2780-157, Portugal
| | - Nikola Lončar
- Gecco Biotech, Nijenborgh 4, Groningen 9747AG, the Netherlands
| | - Lígia O. Martins
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade NOVA de Lisboa, Av. da República, Oeiras 2780-157, Portugal
| | - Smilja Todorovic
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade NOVA de Lisboa, Av. da República, Oeiras 2780-157, Portugal
| | - Célia M. Silveira
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade NOVA de Lisboa, Av. da República, Oeiras 2780-157, Portugal
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4
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Aydin Y, Böttke T, Lam JH, Ernicke S, Fortmann A, Tretbar M, Zarzycka B, Gurevich VV, Katritch V, Coin I. Structural details of a Class B GPCR-arrestin complex revealed by genetically encoded crosslinkers in living cells. Nat Commun 2023; 14:1151. [PMID: 36859440 PMCID: PMC9977954 DOI: 10.1038/s41467-023-36797-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Accepted: 02/16/2023] [Indexed: 03/03/2023] Open
Abstract
Understanding the molecular basis of arrestin-mediated regulation of GPCRs is critical for deciphering signaling mechanisms and designing functional selectivity. However, structural studies of GPCR-arrestin complexes are hampered by their highly dynamic nature. Here, we dissect the interaction of arrestin-2 (arr2) with the secretin-like parathyroid hormone 1 receptor PTH1R using genetically encoded crosslinking amino acids in live cells. We identify 136 intermolecular proximity points that guide the construction of energy-optimized molecular models for the PTH1R-arr2 complex. Our data reveal flexible receptor elements missing in existing structures, including intracellular loop 3 and the proximal C-tail, and suggest a functional role of a hitherto overlooked positively charged region at the arrestin N-edge. Unbiased MD simulations highlight the stability and dynamic nature of the complex. Our integrative approach yields structural insights into protein-protein complexes in a biologically relevant live-cell environment and provides information inaccessible to classical structural methods, while also revealing the dynamics of the system.
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Affiliation(s)
- Yasmin Aydin
- Faculty of Life Sciences, Institute of Biochemistry, Leipzig University, Bruederstr. 34, 04103, Leipzig, Germany
| | - Thore Böttke
- Faculty of Life Sciences, Institute of Biochemistry, Leipzig University, Bruederstr. 34, 04103, Leipzig, Germany
| | - Jordy Homing Lam
- Department of Quantitative and Computational Biology, University of Southern California, Los Angeles, CA, USA
| | - Stefan Ernicke
- Faculty of Life Sciences, Institute of Biochemistry, Leipzig University, Bruederstr. 34, 04103, Leipzig, Germany
| | - Anna Fortmann
- Faculty of Life Sciences, Institute of Biochemistry, Leipzig University, Bruederstr. 34, 04103, Leipzig, Germany
| | - Maik Tretbar
- Medical Faculty, Institute for Drug Discovery, Leipzig University, Bruederstr. 34, 04103, Leipzig, Germany
| | - Barbara Zarzycka
- Division of Medicinal Chemistry, Amsterdam Institute of Molecular and Life Sciences (AIMMS), Faculty of Science, Vrije Universiteit Amsterdam, De Boelelaan 1108, 1081 HZ, Amsterdam, The Netherlands
| | - Vsevolod V Gurevich
- Department of Phar-macology, Vanderbilt University, Nashville, TN, 37232-0146, USA
| | - Vsevolod Katritch
- Department of Quantitative and Computational Biology, University of Southern California, Los Angeles, CA, USA. .,Department of Chemistry, Bridge Institute, USC Michelson Center for Convergent Biosciences, University of Southern California, Los Angeles, CA, USA.
| | - Irene Coin
- Faculty of Life Sciences, Institute of Biochemistry, Leipzig University, Bruederstr. 34, 04103, Leipzig, Germany.
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5
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León-González JA, Flatet P, Juárez-Ramírez MS, Farías-Rico JA. Folding and Evolution of a Repeat Protein on the Ribosome. Front Mol Biosci 2022; 9:851038. [PMID: 35707224 PMCID: PMC9189291 DOI: 10.3389/fmolb.2022.851038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2022] [Accepted: 04/27/2022] [Indexed: 12/04/2022] Open
Abstract
Life on earth is the result of the work of proteins, the cellular nanomachines that fold into elaborated 3D structures to perform their functions. The ribosome synthesizes all the proteins of the biosphere, and many of them begin to fold during translation in a process known as cotranslational folding. In this work we discuss current advances of this field and provide computational and experimental data that highlight the role of ribosome in the evolution of protein structures. First, we used the sequence of the Ankyrin domain from the Drosophila Notch receptor to launch a deep sequence-based search. With this strategy, we found a conserved 33-residue motif shared by different protein folds. Then, to see how the vectorial addition of the motif would generate a full structure we measured the folding on the ribosome of the Ankyrin repeat protein. Not only the on-ribosome folding data is in full agreement with classical in vitro biophysical measurements but also it provides experimental evidence on how folded proteins could have evolved by duplication and fusion of smaller fragments in the RNA world. Overall, we discuss how the ribosomal exit tunnel could be conceptualized as an active site that is under evolutionary pressure to influence protein folding.
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Affiliation(s)
- José Alberto León-González
- Synthetic Biology Program, Center for Genome Sciences, National Autonomous University of Mexico, Cuernavaca, Mexico
| | - Perline Flatet
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
| | - María Soledad Juárez-Ramírez
- Synthetic Biology Program, Center for Genome Sciences, National Autonomous University of Mexico, Cuernavaca, Mexico
| | - José Arcadio Farías-Rico
- Synthetic Biology Program, Center for Genome Sciences, National Autonomous University of Mexico, Cuernavaca, Mexico
- *Correspondence: José Arcadio Farías-Rico,
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6
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The pocketome of G-protein-coupled receptors reveals previously untargeted allosteric sites. Nat Commun 2022; 13:2567. [PMID: 35538063 PMCID: PMC9091257 DOI: 10.1038/s41467-022-29609-6] [Citation(s) in RCA: 35] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Accepted: 03/14/2022] [Indexed: 01/14/2023] Open
Abstract
G-protein-coupled receptors do not only feature the orthosteric pockets, where most endogenous agonists bind, but also a multitude of other allosteric pockets that have come into the focus as potential binding sites for synthetic modulators. Here, to better characterise such pockets, we investigate 557 GPCR structures by exhaustively docking small molecular probes in silico and converting the ensemble of binding locations to pocket-defining volumes. Our analysis confirms all previously identified pockets and reveals nine previously untargeted sites. In order to test for the feasibility of functional modulation of receptors through binding of a ligand to such sites, we mutate residues in two sites, in two model receptors, the muscarinic acetylcholine receptor M3 and β2-adrenergic receptor. Moreover, we analyse the correlation of inter-residue contacts with the activation states of receptors and show that contact patterns closely correlating with activation indeed coincide with these sites.
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7
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Asli A, Higazy-Mreih S, Avital-Shacham M, Kosloff M. Residue-level determinants of RGS R4 subfamily GAP activity and specificity towards the G i subfamily. Cell Mol Life Sci 2021; 78:6305-6318. [PMID: 34292354 PMCID: PMC11072900 DOI: 10.1007/s00018-021-03898-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Revised: 06/18/2021] [Accepted: 07/09/2021] [Indexed: 01/01/2023]
Abstract
The structural basis for the GTPase-accelerating activity of regulators of G protein signaling (RGS) proteins, as well as the mechanistic basis for their specificity in interacting with the heterotrimeric (αβγ) G proteins they inactivate, is not sufficiently understood at the family level. Here, we used biochemical assays to compare RGS domains across the RGS family and map those individual residues that favorably contribute to GTPase-accelerating activity, and those residues responsible for attenuating RGS domain interactions with Gα subunits. We show that conserved interactions of RGS residues with both the Gα switch I and II regions are crucial for RGS activity, while the reciprocal effects of "modulatory" and "disruptor" residues selectively modulate RGS activity. Our results quantify how specific interactions between RGS domains and Gα subunits are set by a balance between favorable RGS residue interactions with particular Gα switch regions, and unfavorable interactions with the Gα helical domain.
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Affiliation(s)
- Ali Asli
- The Department of Human Biology, Faculty of Natural Science, University of Haifa, 199 Aba Khoushy Ave., Mt. Carmel, 3498838, Haifa, Israel
| | - Sabreen Higazy-Mreih
- The Department of Human Biology, Faculty of Natural Science, University of Haifa, 199 Aba Khoushy Ave., Mt. Carmel, 3498838, Haifa, Israel
| | - Meirav Avital-Shacham
- The Department of Human Biology, Faculty of Natural Science, University of Haifa, 199 Aba Khoushy Ave., Mt. Carmel, 3498838, Haifa, Israel
| | - Mickey Kosloff
- The Department of Human Biology, Faculty of Natural Science, University of Haifa, 199 Aba Khoushy Ave., Mt. Carmel, 3498838, Haifa, Israel.
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8
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Hu B, Wang Y, Li N, Zhang S, Luo G, Huang Z. Highly convenient and highly specific-and-sensitive PCR using Se-atom modified dNTPs. Chem Commun (Camb) 2021; 57:57-60. [PMID: 33346277 DOI: 10.1039/d0cc06172g] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Primer design and condition optimization for PCR are tedious and labour-intensive. To conveniently achieve high selectivity, sensitivity and robustness, herein, we first report a new strategy with Se-dNTPs to enhance PCR specificity (over 240-fold) and sensitivity (up to single-digit), effectively eliminating non-specific products and simplifing PCR design and optimization.
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Affiliation(s)
- Bei Hu
- Key Laboratory of Bio-Resource and Eco-environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, Sichuan 610064, P. R. China
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9
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Capturing Peptide-GPCR Interactions and Their Dynamics. Molecules 2020; 25:molecules25204724. [PMID: 33076289 PMCID: PMC7587574 DOI: 10.3390/molecules25204724] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 10/08/2020] [Accepted: 10/09/2020] [Indexed: 12/16/2022] Open
Abstract
Many biological functions of peptides are mediated through G protein-coupled receptors (GPCRs). Upon ligand binding, GPCRs undergo conformational changes that facilitate the binding and activation of multiple effectors. GPCRs regulate nearly all physiological processes and are a favorite pharmacological target. In particular, drugs are sought after that elicit the recruitment of selected effectors only (biased ligands). Understanding how ligands bind to GPCRs and which conformational changes they induce is a fundamental step toward the development of more efficient and specific drugs. Moreover, it is emerging that the dynamic of the ligand–receptor interaction contributes to the specificity of both ligand recognition and effector recruitment, an aspect that is missing in structural snapshots from crystallography. We describe here biochemical and biophysical techniques to address ligand–receptor interactions in their structural and dynamic aspects, which include mutagenesis, crosslinking, spectroscopic techniques, and mass-spectrometry profiling. With a main focus on peptide receptors, we present methods to unveil the ligand–receptor contact interface and methods that address conformational changes both in the ligand and the GPCR. The presented studies highlight a wide structural heterogeneity among peptide receptors, reveal distinct structural changes occurring during ligand binding and a surprisingly high dynamics of the ligand–GPCR complexes.
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10
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Böttke T, Ernicke S, Serfling R, Ihling C, Burda E, Gurevich VV, Sinz A, Coin I. Exploring GPCR-arrestin interfaces with genetically encoded crosslinkers. EMBO Rep 2020; 21:e50437. [PMID: 32929862 PMCID: PMC7645262 DOI: 10.15252/embr.202050437] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Revised: 08/10/2020] [Accepted: 08/13/2020] [Indexed: 12/18/2022] Open
Abstract
β‐arrestins (βarr1 and βarr2) are ubiquitous regulators of G protein‐coupled receptor (GPCR) signaling. Available data suggest that β‐arrestins dock to different receptors in different ways. However, the structural characterization of GPCR‐arrestin complexes is challenging and alternative approaches to study GPCR‐arrestin complexes are needed. Here, starting from the finger loop as a major site for the interaction of arrestins with GPCRs, we genetically incorporate non‐canonical amino acids for photo‐ and chemical crosslinking into βarr1 and βarr2 and explore binding topologies to GPCRs forming either stable or transient complexes with arrestins: the vasopressin receptor 2 (rhodopsin‐like), the corticotropin‐releasing factor receptor 1, and the parathyroid hormone receptor 1 (both secretin‐like). We show that each receptor leaves a unique footprint on arrestins, whereas the two β‐arrestins yield quite similar crosslinking patterns. Furthermore, we show that the method allows defining the orientation of arrestin with respect to the GPCR. Finally, we provide direct evidence for the formation of arrestin oligomers in the cell.
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Affiliation(s)
- Thore Böttke
- Institute of Biochemistry, Faculty of Life Sciences, University of Leipzig, Leipzig, Germany
| | - Stefan Ernicke
- Institute of Biochemistry, Faculty of Life Sciences, University of Leipzig, Leipzig, Germany
| | - Robert Serfling
- Institute of Biochemistry, Faculty of Life Sciences, University of Leipzig, Leipzig, Germany
| | - Christian Ihling
- Institute of Pharmacy, Department of Pharmaceutical Chemistry and Bioanalytics, Charles Tanford Protein Center, Martin Luther University Halle-Wittenberg, Halle/Saale, Germany
| | - Edyta Burda
- Institute of Pharmacy, Faculty of Medicine, University of Leipzig, Leipzig, Germany
| | | | - Andrea Sinz
- Institute of Pharmacy, Department of Pharmaceutical Chemistry and Bioanalytics, Charles Tanford Protein Center, Martin Luther University Halle-Wittenberg, Halle/Saale, Germany
| | - Irene Coin
- Institute of Biochemistry, Faculty of Life Sciences, University of Leipzig, Leipzig, Germany
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11
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Somuncu S, Somuncu ÖS, Ballıca B, Tabandeh B. Deficiency of epithelial-mesenchymal transition causes child indirect inguinal hernia. J Pediatr Surg 2020; 55:665-671. [PMID: 31288923 DOI: 10.1016/j.jpedsurg.2019.06.020] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Revised: 06/11/2019] [Accepted: 06/21/2019] [Indexed: 12/24/2022]
Abstract
INTRODUCTION Epithelial-mesenchymal transition (EMT) describes rapid changes in cellular phenotype. During EMT, epithelial cells down-modulate cell-cell adhesion, alter polarity, reorganize cytoskeleton, become isolated, motile, and resistant to anoikis. Epithelial breakdown and epithelial cell migration are the key processes involved in the obliteration of processus vaginalis. The great majority of abnormalities are because of nonobliteration or incomplete fusion of PV. We aimed to analyze the quantitative changes of epithelial genes in adult/child patients and their controls to examine differences of the genesis of these hernias. We also aimed to investigate the potential epigenetic causes of indirect inguinal hernia in adult patients. METHODS Ten adult, ten child indirect inguinal hernia sacs and ten adult, ten child parietal peritonea were used. Hernial sac samples were obtained from indirect inguinal hernia surgeries. Peritonea of adult patients who underwent open cholecystectomy for cholelithiasis via subcostal incision were included in the study as the healthy control groups. Ages of the children were selected to be between 0 and 5 whereas the age of adults was chosen as 35-55, respectively. Total RNA isolation and cDNA synthesis were made from hernia sacs and peritoneum samples. Relative Keratin 1, Keratin 15, Filaggrin2 and STAT3 expressions were analyzed via qPCR. Indirect inguinal hernia sac cells were seeded and grown in vitro. Child diseased cells were employed in immunocytochemistry (ICC) analysis for Cytokeratin 15, Filaggrin2 and Bcl-2. Adult indirect inguinal hernia cells were examined for H3 modifications through ICC. RESULTS In child indirect inguinal hernia, Keratin expressions were found higher than their controls. They were meaningfully lower than the healthy group in adult indirect inguinal hernia. Keratin 15, Keratin 1 and Filaggrin2 expressions were all correlating since they are members of related pathways. STAT3 expressions were opposite to Keratin and Filaggrin expressions suggesting that adult cells might have a switch to the mesenchymal state from the epithelial state. Adult indirect inguinal hernia samples have switched to the mesenchymal state whereas child indirect inguinal hernia samples have shown lack of transition. CONCLUSION Irregular changes of EMT associated genes act in the progression of indirect inguinal hernia. Hence, the information on the epigenetic regulation of EMT in patients with primary inguinal hernia can aid to comprehend the pathogenesis in adults and infers new therapeutic approaches for this disease. TYPE OF STUDY Prognosis study. LEVEL OF EVIDENCE Level 2.
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Affiliation(s)
- Salih Somuncu
- Bezmialem Vakıf University Hospital, Department of Pediatric Surgery, Turkey.
| | - Özge Sezin Somuncu
- Bahçeşehir University, Faculty of Medicine, Department of Basic Sciences, Turkey
| | | | - Babek Tabandeh
- Bahçeşehir University, Faculty of Medicine, Department of General Surgery, Turkey
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12
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Heydenreich FM, Miljuš T, Milić D, Veprintsev DB. High-throughput Site-directed Scanning Mutagenesis Using a Two-fragment PCR Approach. Bio Protoc 2020; 10:e3484. [PMID: 33654716 DOI: 10.21769/bioprotoc.3484] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Revised: 11/26/2019] [Accepted: 12/28/2019] [Indexed: 11/02/2022] Open
Abstract
Site-directed scanning mutagenesis is a useful tool applied in studying protein function and designing proteins with new properties, such as increased stability or enzymatic activity. Creating a systematic library of hundreds of site-directed mutants is still a demanding and expensive task. The established protocols for making such libraries include PCR amplification of the recombinant DNA using a pair of primers carrying a target mutation in the same PCR. Unfortunately, this approach is very often coupled with PCR artifacts which compromise overall efficiency of site-directed mutagenesis. To reduce the failure rate due to the PCR artifacts, we have set up a high-throughput mutagenesis protocol based on a two-fragment PCR approach. To this end, each mutation is introduced in two separate PCRs resulting in two linear fragments of the mutated plasmid. In the next steps, the PCR template is digested and the two matching plasmid fragments are joined together using Gibson assembly. Separating the corresponding mutagenic primers into two different PCRs decreases a number of artifacts and thus increases overall cloning efficiency. Furthermore, free software that we developed facilitates both high-throughput primer design and analysis of sequencing results. Overall, this protocol enabled us to efficiently produce several alanine-scanning libraries of 400 single-point mutations with complete coverage of the protein sequence.
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Affiliation(s)
- Franziska M Heydenreich
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA, USA
| | - Tamara Miljuš
- Institute of Metabolism and Systems Research, University of Birmingham, Birmingham, UK.,Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, Midlands, UK
| | - Dalibor Milić
- Department of Structural and Computational Biology, Max Perutz Labs, University of Vienna, Vienna, Austria
| | - Dmitry B Veprintsev
- Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, Midlands, UK.,School of Life Sciences, University of Nottingham, Nottingham, NG7 2UH, UK
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13
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Bozovičar K, Bratkovič T. Evolving a Peptide: Library Platforms and Diversification Strategies. Int J Mol Sci 2019; 21:E215. [PMID: 31892275 PMCID: PMC6981544 DOI: 10.3390/ijms21010215] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Revised: 12/22/2019] [Accepted: 12/25/2019] [Indexed: 12/22/2022] Open
Abstract
Peptides are widely used in pharmaceutical industry as active pharmaceutical ingredients, versatile tools in drug discovery, and for drug delivery. They find themselves at the crossroads of small molecules and proteins, possessing favorable tissue penetration and the capability to engage into specific and high-affinity interactions with endogenous receptors. One of the commonly employed approaches in peptide discovery and design is to screen combinatorial libraries, comprising a myriad of peptide variants of either chemical or biological origin. In this review, we focus mainly on recombinant peptide libraries, discussing different platforms for their display or expression, and various diversification strategies for library design. We take a look at well-established technologies as well as new developments and future directions.
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Affiliation(s)
| | - Tomaž Bratkovič
- Department of Pharmaceutical Biology, Faculty of Pharmacy, University of Ljubljana, Aškerčeva Cesta 7, SI-1000 Ljubljana, Slovenia;
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14
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Lari A, Arul Nambi Rajan A, Sandhu R, Reiter T, Montpetit R, Young BP, Loewen CJ, Montpetit B. A nuclear role for the DEAD-box protein Dbp5 in tRNA export. eLife 2019; 8:48410. [PMID: 31453808 PMCID: PMC6711706 DOI: 10.7554/elife.48410] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Accepted: 08/09/2019] [Indexed: 01/01/2023] Open
Abstract
Dbp5 is an essential DEAD-box protein that mediates nuclear mRNP export. Dbp5 also shuttles between nuclear and cytoplasmic compartments with reported roles in transcription, ribosomal subunit export, and translation; however, the mechanism(s) by which nucleocytoplasmic transport occurs and how Dbp5 specifically contributes to each of these processes remains unclear. Towards understanding the functions and transport of Dbp5 in Saccharomyces cerevisiae, alanine scanning mutagenesis was used to generate point mutants at all possible residues within a GFP-Dbp5 reporter. Characterization of the 456 viable mutants led to the identification of an N-terminal Xpo1-dependent nuclear export signal in Dbp5, in addition to other separation-of-function alleles, which together provide evidence that Dbp5 nuclear shuttling is not essential for mRNP export. Rather, disruptions in Dbp5 nucleocytoplasmic transport result in tRNA export defects, including changes in tRNA shuttling dynamics during recovery from nutrient stress.
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Affiliation(s)
- Azra Lari
- Department of Cell Biology, University of Alberta, Edmonton, Canada
| | - Arvind Arul Nambi Rajan
- Biochemistry, Molecular, Cellular and Developmental Biology Graduate Group, University of California, Davis, Davis, United States
| | - Rima Sandhu
- Department of Viticulture and Enology, University of California, Davis, Davis, United States
| | - Taylor Reiter
- Food Science Graduate Group, University of California Davis, Davis, United States
| | - Rachel Montpetit
- Department of Viticulture and Enology, University of California, Davis, Davis, United States
| | - Barry P Young
- Department of Cellular and Physiological Sciences, Life Sciences Institute, University of British Columbia, Vancouver, Canada
| | - Chris Jr Loewen
- Department of Cellular and Physiological Sciences, Life Sciences Institute, University of British Columbia, Vancouver, Canada
| | - Ben Montpetit
- Department of Cell Biology, University of Alberta, Edmonton, Canada.,Biochemistry, Molecular, Cellular and Developmental Biology Graduate Group, University of California, Davis, Davis, United States.,Department of Viticulture and Enology, University of California, Davis, Davis, United States.,Food Science Graduate Group, University of California Davis, Davis, United States
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15
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Fürst MJLJ, Boonstra M, Bandstra S, Fraaije MW. Stabilization of cyclohexanone monooxygenase by computational and experimental library design. Biotechnol Bioeng 2019; 116:2167-2177. [PMID: 31124128 PMCID: PMC6836875 DOI: 10.1002/bit.27022] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Revised: 05/14/2019] [Accepted: 05/18/2019] [Indexed: 12/23/2022]
Abstract
Enzymes often by far exceed the activity, selectivity, and sustainability achieved with chemical catalysts. One of the main reasons for the lack of biocatalysis in the chemical industry is the poor stability exhibited by many enzymes when exposed to process conditions. This dilemma is exemplified in the usually very temperature‐sensitive enzymes catalyzing the Baeyer–Villiger reaction, which display excellent stereo‐ and regioselectivity and offer a green alternative to the commonly used, explosive peracids. Here we describe a protein engineering approach applied to cyclohexanone monooxygenase from Rhodococcus sp. HI‐31, a substrate‐promiscuous enzyme that efficiently catalyzes the production of the nylon‐6 precursor ε‐caprolactone. We used a framework for rapid enzyme stabilization by computational libraries (FRESCO), which predicts protein‐stabilizing mutations. From 128 screened point mutants, approximately half had a stabilizing effect, albeit mostly to a small degree. To overcome incompatibility effects observed upon combining the best hits, an easy shuffled library design strategy was devised. The most stable and highly active mutant displayed an increase in unfolding temperature of 13°C and an approximately 33x increase in half‐life at 30°C. In contrast to the wild‐type enzyme, this thermostable 8x mutant is an attractive biocatalyst for biotechnological applications.
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Affiliation(s)
| | - Marjon Boonstra
- Molecular Enzymology Group, University of Groningen, Groningen, The Netherlands
| | - Selle Bandstra
- Molecular Enzymology Group, University of Groningen, Groningen, The Netherlands
| | - Marco W Fraaije
- Molecular Enzymology Group, University of Groningen, Groningen, The Netherlands
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16
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Lim CC, Choong YS, Lim TS. Cognizance of Molecular Methods for the Generation of Mutagenic Phage Display Antibody Libraries for Affinity Maturation. Int J Mol Sci 2019; 20:E1861. [PMID: 30991723 PMCID: PMC6515083 DOI: 10.3390/ijms20081861] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Revised: 04/10/2019] [Accepted: 04/12/2019] [Indexed: 12/25/2022] Open
Abstract
Antibodies leverage on their unique architecture to bind with an array of antigens. The strength of interaction has a direct relation to the affinity of the antibodies towards the antigen. In vivo affinity maturation is performed through multiple rounds of somatic hypermutation and selection in the germinal centre. This unique process involves intricate sequence rearrangements at the gene level via molecular mechanisms. The emergence of in vitro display technologies, mainly phage display and recombinant DNA technology, has helped revolutionize the way antibody improvements are being carried out in the laboratory. The adaptation of molecular approaches in vitro to replicate the in vivo processes has allowed for improvements in the way recombinant antibodies are designed and tuned. Combinatorial libraries, consisting of a myriad of possible antibodies, are capable of replicating the diversity of the natural human antibody repertoire. The isolation of target-specific antibodies with specific affinity characteristics can also be accomplished through modification of stringent protocols. Despite the ability to screen and select for high-affinity binders, some 'fine tuning' may be required to enhance antibody binding in terms of its affinity. This review will provide a brief account of phage display technology used for antibody generation followed by a summary of different combinatorial library characteristics. The review will focus on available strategies, which include molecular approaches, next generation sequencing, and in silico approaches used for antibody affinity maturation in both therapeutic and diagnostic applications.
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Affiliation(s)
- Chia Chiu Lim
- Institute for Research in Molecular Medicine, Universiti Sains Malaysia, Penang 11800, Malaysia.
| | - Yee Siew Choong
- Institute for Research in Molecular Medicine, Universiti Sains Malaysia, Penang 11800, Malaysia.
| | - Theam Soon Lim
- Institute for Research in Molecular Medicine, Universiti Sains Malaysia, Penang 11800, Malaysia.
- Analytical Biochemistry Research Centre, Universiti Sains Malaysia, Penang 11800, Malaysia.
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17
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Haider RS, Wilhelm F, Rizk A, Mutt E, Deupi X, Peterhans C, Mühle J, Berger P, Schertler GFX, Standfuss J, Ostermaier MK. Arrestin-1 engineering facilitates complex stabilization with native rhodopsin. Sci Rep 2019; 9:439. [PMID: 30679635 PMCID: PMC6346018 DOI: 10.1038/s41598-018-36881-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Accepted: 11/23/2018] [Indexed: 01/14/2023] Open
Abstract
Arrestin-1 desensitizes the activated and phosphorylated photoreceptor rhodopsin by forming transient rhodopsin−arrestin-1 complexes that eventually decay to opsin, retinal and arrestin-1. Via a multi-dimensional screening setup, we identified and combined arrestin-1 mutants that form lasting complexes with light-activated and phosphorylated rhodopsin in harsh conditions, such as high ionic salt concentration. Two quadruple mutants, D303A + T304A + E341A + F375A and R171A + T304A + E341A + F375A share similar heterologous expression and thermo-stability levels with wild type (WT) arrestin-1, but are able to stabilize complexes with rhodopsin with more than seven times higher half-maximal inhibitory concentration (IC50) values for NaCl compared to the WT arrestin-1 protein. These quadruple mutants are also characterized by higher binding affinities to phosphorylated rhodopsin, light-activated rhodopsin and phosphorylated opsin, as compared with WT arrestin-1. Furthermore, the assessed arrestin-1 mutants are still specifically associating with phosphorylated or light-activated receptor states only, while binding to the inactive ground state of the receptor is not significantly altered. Additionally, we propose a novel functionality for R171 in stabilizing the inactive arrestin-1 conformation as well as the rhodopsin–arrestin-1 complex. The achieved stabilization of the active rhodopsin–arrestin-1 complex might be of great interest for future structure determination, antibody development studies as well as drug-screening efforts targeting G protein-coupled receptors (GPCRs).
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Affiliation(s)
- Raphael S Haider
- InterAx Biotech AG, PARK InnovAARE, Villigen, 5234, Switzerland.,Laboratory of Biomolecular Research, Paul Scherrer Institute, Villigen, 5232, Switzerland.,Institute of Molecular Cell Biology, Jena, 07745, Germany
| | - Florian Wilhelm
- InterAx Biotech AG, PARK InnovAARE, Villigen, 5234, Switzerland
| | - Aurélien Rizk
- InterAx Biotech AG, PARK InnovAARE, Villigen, 5234, Switzerland
| | - Eshita Mutt
- Laboratory of Biomolecular Research, Paul Scherrer Institute, Villigen, 5232, Switzerland
| | - Xavier Deupi
- Laboratory of Biomolecular Research, Paul Scherrer Institute, Villigen, 5232, Switzerland
| | - Christian Peterhans
- Laboratory of Biomolecular Research, Paul Scherrer Institute, Villigen, 5232, Switzerland
| | - Jonas Mühle
- Laboratory of Biomolecular Research, Paul Scherrer Institute, Villigen, 5232, Switzerland
| | - Philipp Berger
- Laboratory of Biomolecular Research, Paul Scherrer Institute, Villigen, 5232, Switzerland
| | - Gebhard F X Schertler
- Laboratory of Biomolecular Research, Paul Scherrer Institute, Villigen, 5232, Switzerland.,ETH Zurich, Zurich, 8093, Switzerland
| | - Jörg Standfuss
- Laboratory of Biomolecular Research, Paul Scherrer Institute, Villigen, 5232, Switzerland
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18
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Fürst MJLJ, Martin C, Lončar N, Fraaije MW. Experimental Protocols for Generating Focused Mutant Libraries and Screening for Thermostable Proteins. Methods Enzymol 2018; 608:151-187. [PMID: 30173762 DOI: 10.1016/bs.mie.2018.04.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Many proteins are rapidly deactivated when exposed to high or even ambient temperatures. This cannot only impede the study of a particular protein, but also is one of the major reasons why enzyme catalysis is still widely unable to compete with established chemical processes. Furthermore, differences in protein stability are a challenge in synthetic biology, when individual modules prove to be incompatible. The targeted stabilization of proteins can overcome these hurdles, and protein engineering techniques are more and more reliably supported by computational chemistry tools. Accordingly, algorithms to predict the differences in folding energy of a mutant compared to the wild-type, ΔΔGfold, are used in the highly successful FRESCO workflow. The resulting single mutant prediction library consists typically of a few hundred amino acid exchanges, and after combining the most successful hits we so far obtained stabilized mutants which exhibited increases in apparent melting temperature of 20-35°C and showed vastly increased half-lives, as well as resistance to cosolvents. Here, we report a detailed protocol to generate these mutant libraries experimentally, covering the entire workflow from primer design, through mutagenesis, protein production and screening, to mutation combination strategies. The individual parts of the method are furthermore applicable to many other scenarios besides protein stabilization, and these protocols are valuable for any project requiring individual or semi high-throughput site-directed mutagenesis, protein expression and purification, or generation of mutant combination libraries.
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Affiliation(s)
- Max J L J Fürst
- Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, The Netherlands
| | - Caterina Martin
- Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, The Netherlands
| | - Nikola Lončar
- Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, The Netherlands
| | - Marco W Fraaije
- Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, The Netherlands.
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19
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Milić D, Dick M, Mulnaes D, Pfleger C, Kinnen A, Gohlke H, Groth G. Recognition motif and mechanism of ripening inhibitory peptides in plant hormone receptor ETR1. Sci Rep 2018; 8:3890. [PMID: 29497085 PMCID: PMC5832771 DOI: 10.1038/s41598-018-21952-3] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Accepted: 02/13/2018] [Indexed: 12/21/2022] Open
Abstract
Synthetic peptides derived from ethylene-insensitive protein 2 (EIN2), a central regulator of ethylene signalling, were recently shown to delay fruit ripening by interrupting protein-protein interactions in the ethylene signalling pathway. Here, we show that the inhibitory peptide NOP-1 binds to the GAF domain of ETR1 - the prototype of the plant ethylene receptor family. Site-directed mutagenesis and computational studies reveal the peptide interaction site and a plausible molecular mechanism for the ripening inhibition.
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Affiliation(s)
- Dalibor Milić
- Institute of Biochemical Plant Physiology and Bioeconomy Science Center (BioSC), Heinrich Heine University Düsseldorf, Düsseldorf, Germany
- Department of Structural and Computational Biology, Max F. Perutz Laboratories, University of Vienna, Vienna Biocenter, Vienna, Austria
| | - Markus Dick
- Institute of Pharmaceutical and Medicinal Chemistry and Bioeconomy Science Center (BioSC), Heinrich Heine University Düsseldorf, Düsseldorf, Germany
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California, USA
| | - Daniel Mulnaes
- Institute of Pharmaceutical and Medicinal Chemistry and Bioeconomy Science Center (BioSC), Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Christopher Pfleger
- Institute of Pharmaceutical and Medicinal Chemistry and Bioeconomy Science Center (BioSC), Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Anna Kinnen
- Institute of Biochemical Plant Physiology and Bioeconomy Science Center (BioSC), Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Holger Gohlke
- Institute of Pharmaceutical and Medicinal Chemistry and Bioeconomy Science Center (BioSC), Heinrich Heine University Düsseldorf, Düsseldorf, Germany.
- John von Neumann Institute for Computing (NIC), Jülich Supercomputing Centre (JSC) & Institute for Complex Systems - Structural Biochemistry (ICS 6), Forschungszentrum Jülich GmbH, Jülich, Germany.
| | - Georg Groth
- Institute of Biochemical Plant Physiology and Bioeconomy Science Center (BioSC), Heinrich Heine University Düsseldorf, Düsseldorf, Germany.
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20
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Abstract
Directed evolution has emerged as one of the most effective protein engineering methods in basic research as well as in applications in synthetic organic chemistry and biotechnology. The successful engineering of protein activity, allostery, binding affinity, expression, folding, fluorescence, solubility, substrate scope, selectivity (enantio-, stereo-, and regioselectivity), and/or stability (temperature, organic solvents, pH) is just limited by the throughput of the genetic selection, display, or screening system that is available for a given protein. Sometimes it is possible to analyze millions of protein variants from combinatorial libraries per day. In other cases, however, only a few hundred variants can be screened in a single day, and thus the creation of smaller yet smarter libraries is needed. Different strategies have been developed to create these libraries. One approach is to perform mutational scanning or to construct "mutability landscapes" in order to understand sequence-function relationships that can guide the actual directed evolution process. Herein we provide a protocol for economically constructing scanning mutagenesis libraries using a cytochrome P450 enzyme in a high-throughput manner. The goal is to engineer activity, regioselectivity, and stereoselectivity in the oxidative hydroxylation of a steroid, a challenging reaction in synthetic organic chemistry. Libraries based on mutability landscapes can be used to engineer any fitness trait of interest. The protocol is also useful for constructing gene libraries for deep mutational scanning experiments.
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Affiliation(s)
- Carlos G Acevedo-Rocha
- Department of Biocatalysis, Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470, Mülheim an der Ruhr, Germany.
- Department of Chemistry, Philipps-Universität Marburg, Marburg, 35032, Germany.
- Biosyntia ApS, 2100, Copenhagen, Denmark.
| | - Matteo Ferla
- Department of Biochemistry, Oxford University, Oxford, OX1 3QU, UK
| | - Manfred T Reetz
- Department of Biocatalysis, Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470, Mülheim an der Ruhr, Germany
- Department of Chemistry, Philipps-Universität Marburg, Marburg, 35032, Germany
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21
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High-throughput mutagenesis using a two-fragment PCR approach. Sci Rep 2017; 7:6787. [PMID: 28754896 PMCID: PMC5533798 DOI: 10.1038/s41598-017-07010-4] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Accepted: 06/20/2017] [Indexed: 12/19/2022] Open
Abstract
Site-directed scanning mutagenesis is a powerful protein engineering technique which allows studies of protein functionality at single amino acid resolution and design of stabilized proteins for structural and biophysical work. However, creating libraries of hundreds of mutants remains a challenging, expensive and time-consuming process. The efficiency of the mutagenesis step is the key for fast and economical generation of such libraries. PCR artefacts such as misannealing and tandem primer repeats are often observed in mutagenesis cloning and reduce the efficiency of mutagenesis. Here we present a high-throughput mutagenesis pipeline based on established methods that significantly reduces PCR artefacts. We combined a two-fragment PCR approach, in which mutagenesis primers are used in two separate PCR reactions, with an in vitro assembly of resulting fragments. We show that this approach, despite being more laborious, is a very efficient pipeline for the creation of large libraries of mutants.
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22
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Rajatileka S, Odd D, Robinson MT, Spittle AC, Dwomoh L, Williams M, Harding D, Wagstaff M, Owen M, Crosby C, Ching J, Molnár E, Luyt K, Váradi A. Variants of the EAAT2 Glutamate Transporter Gene Promoter Are Associated with Cerebral Palsy in Preterm Infants. Mol Neurobiol 2017; 55:2013-2024. [PMID: 28271401 PMCID: PMC5840247 DOI: 10.1007/s12035-017-0462-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Accepted: 02/16/2017] [Indexed: 11/26/2022]
Abstract
Preterm delivery is associated with neurodevelopmental impairment caused by environmental and genetic factors. Dysfunction of the excitatory amino acid transporter 2 (EAAT2) and the resultant impaired glutamate uptake can lead to neurological disorders. In this study, we investigated the role of single nucleotide polymorphisms (SNPs; g.-200C>A and g.-181A>C) in the EAAT2 promoter in susceptibility to brain injury and neurodisability in very preterm infants born at or before 32-week gestation. DNA isolated from newborns’ dried blood spots were used for pyrosequencing to detect both SNPs. Association between EAAT2 genotypes and cerebral palsy, cystic periventricular leukomalacia and a low developmental score was then assessed. The two SNPs were concordant in 89.4% of infants resulting in three common genotypes all carrying two C and two A alleles in different combinations. However, in 10.6% of cases, non-concordance was found, generating six additional rare genotypes. The A alleles at both loci appeared to be detrimental and consequently, the risk of developing cerebral palsy increased four- and sixfold for each additional detrimental allele at -200 and -181 bp, respectively. The two SNPs altered the regulation of the EAAT2 promoter activity and glutamate homeostasis. This study highlights the significance of glutamate in the pathogenesis of preterm brain injury and subsequent development of cerebral palsy and neurodevelopmental disabilities. Furthermore, the described EAAT2 SNPs may be an early biomarker of vulnerability to neurodisability and may aid the development of targeted treatment strategies.
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Affiliation(s)
- Shavanthi Rajatileka
- Centre for Research in Biosciences, Department of Applied Sciences, Faculty of Health and Applied Sciences, University of the West of England, Bristol, BS16 1QY, UK
| | - David Odd
- Neonatal Neuroscience, School of Clinical Sciences, University of Bristol, St Michael's Hospital, Southwell Street, Bristol, BS2 8EG, UK
- Neonatal Intensive Care Unit, Southmead Hospital, North Bristol NHS Trust, Bristol, BS10 5NB, UK
| | - Matthew T Robinson
- College of Life & Environmental Sciences, University of Exeter, Stocker Road, Exeter, EX4 4QD, UK
| | - Alexandra C Spittle
- Centre for Synaptic Plasticity, School of Physiology, Pharmacology and Neuroscience, University of Bristol, Biomedical Sciences Building, University Walk, Bristol, BS8 1TD, UK
| | - Louis Dwomoh
- Centre for Research in Biosciences, Department of Applied Sciences, Faculty of Health and Applied Sciences, University of the West of England, Bristol, BS16 1QY, UK
| | - Maggie Williams
- Bristol Genetics Laboratory, Pathology Sciences, Blood Sciences and Bristol Genetics, Southmead Hospital, Bristol, BS10 5NB, UK
| | - David Harding
- Regional Neonatal Intensive Care Unit, St Michael's Hospital, University Hospital NHS Trust, Bristol, BS2 8EG, UK
| | - Miles Wagstaff
- Neonatal Intensive Care Unit, Gloucestershire Royal Hospital, Gloucestershire NHS Trust, Gloucester, GL1 3NN, UK
| | - Marie Owen
- Neonatal Intensive Care Unit, Gloucestershire Royal Hospital, Gloucestershire NHS Trust, Gloucester, GL1 3NN, UK
| | - Charlene Crosby
- Bristol Genetics Laboratory, Pathology Sciences, Blood Sciences and Bristol Genetics, Southmead Hospital, Bristol, BS10 5NB, UK
| | - Jared Ching
- Neonatal Neuroscience, School of Clinical Sciences, University of Bristol, St Michael's Hospital, Southwell Street, Bristol, BS2 8EG, UK
| | - Elek Molnár
- Centre for Synaptic Plasticity, School of Physiology, Pharmacology and Neuroscience, University of Bristol, Biomedical Sciences Building, University Walk, Bristol, BS8 1TD, UK
| | - Karen Luyt
- Neonatal Neuroscience, School of Clinical Sciences, University of Bristol, St Michael's Hospital, Southwell Street, Bristol, BS2 8EG, UK
- Regional Neonatal Intensive Care Unit, St Michael's Hospital, University Hospital NHS Trust, Bristol, BS2 8EG, UK
| | - Anikó Váradi
- Centre for Research in Biosciences, Department of Applied Sciences, Faculty of Health and Applied Sciences, University of the West of England, Bristol, BS16 1QY, UK.
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23
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Farías-Rico JA, Goetz SK, Marino J, von Heijne G. Mutational analysis of protein folding inside the ribosome exit tunnel. FEBS Lett 2016; 591:155-163. [DOI: 10.1002/1873-3468.12504] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2016] [Revised: 11/18/2016] [Accepted: 11/22/2016] [Indexed: 12/23/2022]
Affiliation(s)
- José Arcadio Farías-Rico
- Department of Biochemistry and Biophysics; Center for Biomembrane Research; Stockholm University; Sweden
| | - Sara Kathrin Goetz
- Department of Biochemistry and Biophysics; Center for Biomembrane Research; Stockholm University; Sweden
| | - Jacopo Marino
- Gene Center and Center for Integrated Protein Science Munich; CiPS-M; University of Munich; Germany
| | - Gunnar von Heijne
- Department of Biochemistry and Biophysics; Center for Biomembrane Research; Stockholm University; Sweden
- Science for Life Laboratory; Stockholm University; Solna Sweden
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24
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Mingo J, Erramuzpe A, Luna S, Aurtenetxe O, Amo L, Diez I, Schepens JTG, Hendriks WJAJ, Cortés JM, Pulido R. One-Tube-Only Standardized Site-Directed Mutagenesis: An Alternative Approach to Generate Amino Acid Substitution Collections. PLoS One 2016; 11:e0160972. [PMID: 27548698 PMCID: PMC4993582 DOI: 10.1371/journal.pone.0160972] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Accepted: 07/27/2016] [Indexed: 12/30/2022] Open
Abstract
Site-directed mutagenesis (SDM) is a powerful tool to create defined collections of protein variants for experimental and clinical purposes, but effectiveness is compromised when a large number of mutations is required. We present here a one-tube-only standardized SDM approach that generates comprehensive collections of amino acid substitution variants, including scanning- and single site-multiple mutations. The approach combines unified mutagenic primer design with the mixing of multiple distinct primer pairs and/or plasmid templates to increase the yield of a single inverse-PCR mutagenesis reaction. Also, a user-friendly program for automatic design of standardized primers for Ala-scanning mutagenesis is made available. Experimental results were compared with a modeling approach together with stochastic simulation data. For single site-multiple mutagenesis purposes and for simultaneous mutagenesis in different plasmid backgrounds, combination of primer sets and/or plasmid templates in a single reaction tube yielded the distinct mutations in a stochastic fashion. For scanning mutagenesis, we found that a combination of overlapping primer sets in a single PCR reaction allowed the yield of different individual mutations, although this yield did not necessarily follow a stochastic trend. Double mutants were generated when the overlap of primer pairs was below 60%. Our results illustrate that one-tube-only SDM effectively reduces the number of reactions required in large-scale mutagenesis strategies, facilitating the generation of comprehensive collections of protein variants suitable for functional analysis.
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Affiliation(s)
- Janire Mingo
- Biomarkers in Cancer Unit, Biocruces Health Research Institute, Barakaldo, Spain
| | - Asier Erramuzpe
- Quantitative Biomedicine Unit, Biocruces Health Research Institute, Barakaldo, Spain
| | - Sandra Luna
- Biomarkers in Cancer Unit, Biocruces Health Research Institute, Barakaldo, Spain
| | - Olaia Aurtenetxe
- Biomarkers in Cancer Unit, Biocruces Health Research Institute, Barakaldo, Spain
| | - Laura Amo
- Biomarkers in Cancer Unit, Biocruces Health Research Institute, Barakaldo, Spain
| | - Ibai Diez
- Quantitative Biomedicine Unit, Biocruces Health Research Institute, Barakaldo, Spain
| | - Jan T. G. Schepens
- Department of Cell Biology, Nijmegen Centre for Molecular Life Sciences, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
| | - Wiljan J. A. J. Hendriks
- Department of Cell Biology, Nijmegen Centre for Molecular Life Sciences, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
| | - Jesús M. Cortés
- Quantitative Biomedicine Unit, Biocruces Health Research Institute, Barakaldo, Spain
- IKERBASQUE, Basque Foundation for Science, Bilbao, Spain
| | - Rafael Pulido
- Biomarkers in Cancer Unit, Biocruces Health Research Institute, Barakaldo, Spain
- IKERBASQUE, Basque Foundation for Science, Bilbao, Spain
- * E-mail: ;
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25
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Venkatakrishnan AJ, Deupi X, Lebon G, Heydenreich FM, Flock T, Miljus T, Balaji S, Bouvier M, Veprintsev DB, Tate CG, Schertler GFX, Babu MM. Diverse activation pathways in class A GPCRs converge near the G-protein-coupling region. Nature 2016; 536:484-7. [PMID: 27525504 DOI: 10.1038/nature19107] [Citation(s) in RCA: 212] [Impact Index Per Article: 26.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Accepted: 07/13/2016] [Indexed: 02/06/2023]
Abstract
Class A G-protein-coupled receptors (GPCRs) are a large family of membrane proteins that mediate a wide variety of physiological functions, including vision, neurotransmission and immune responses. They are the targets of nearly one-third of all prescribed medicinal drugs such as beta blockers and antipsychotics. GPCR activation is facilitated by extracellular ligands and leads to the recruitment of intracellular G proteins. Structural rearrangements of residue contacts in the transmembrane domain serve as 'activation pathways' that connect the ligand-binding pocket to the G-protein-coupling region within the receptor. In order to investigate the similarities in activation pathways across class A GPCRs, we analysed 27 GPCRs from diverse subgroups for which structures of active, inactive or both states were available. Here we show that, despite the diversity in activation pathways between receptors, the pathways converge near the G-protein-coupling region. This convergence is mediated by a highly conserved structural rearrangement of residue contacts between transmembrane helices 3, 6 and 7 that releases G-protein-contacting residues. The convergence of activation pathways may explain how the activation steps initiated by diverse ligands enable GPCRs to bind a common repertoire of G proteins.
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26
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Peterhans C, Lally CCM, Ostermaier MK, Sommer ME, Standfuss J. Functional map of arrestin binding to phosphorylated opsin, with and without agonist. Sci Rep 2016; 6:28686. [PMID: 27350090 PMCID: PMC4923902 DOI: 10.1038/srep28686] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Accepted: 06/01/2016] [Indexed: 01/06/2023] Open
Abstract
Arrestins desensitize G protein-coupled receptors (GPCRs) and act as mediators of signalling. Here we investigated the interactions of arrestin-1 with two functionally distinct forms of the dim-light photoreceptor rhodopsin. Using unbiased scanning mutagenesis we probed the individual contribution of each arrestin residue to the interaction with the phosphorylated apo-receptor (Ops-P) and the agonist-bound form (Meta II-P). Disruption of the polar core or displacement of the C-tail strengthened binding to both receptor forms. In contrast, mutations of phosphate-binding residues (phosphosensors) suggest the phosphorylated receptor C-terminus binds arrestin differently for Meta II-P and Ops-P. Likewise, mutations within the inter-domain interface, variations in the receptor-binding loops and the C-edge of arrestin reveal different binding modes. In summary, our results indicate that arrestin-1 binding to Meta II-P and Ops-P is similarly dependent on arrestin activation, although the complexes formed with these two receptor forms are structurally distinct.
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Affiliation(s)
- Christian Peterhans
- Paul Scherrer Institute, Laboratory for Biomolecular Research, CH-5323, Villigen, Switzerland
| | - Ciara C M Lally
- Institut für Medizinische Physik und Biophysik (CC2), Charité-Universitätsmedizin Berlin, Charitéplatz 1, D-10117, Berlin, Germany
| | - Martin K Ostermaier
- Institut für Medizinische Physik und Biophysik (CC2), Charité-Universitätsmedizin Berlin, Charitéplatz 1, D-10117, Berlin, Germany
| | - Martha E Sommer
- Institut für Medizinische Physik und Biophysik (CC2), Charité-Universitätsmedizin Berlin, Charitéplatz 1, D-10117, Berlin, Germany
| | - Jörg Standfuss
- Paul Scherrer Institute, Laboratory for Biomolecular Research, CH-5323, Villigen, Switzerland
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27
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Sun D, Flock T, Deupi X, Maeda S, Matkovic M, Mendieta S, Mayer D, Dawson R, Schertler GFX, Madan Babu M, Veprintsev DB. Probing Gαi1 protein activation at single-amino acid resolution. Nat Struct Mol Biol 2015; 22:686-694. [PMID: 26258638 PMCID: PMC4876908 DOI: 10.1038/nsmb.3070] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Accepted: 07/17/2015] [Indexed: 11/08/2022]
Abstract
We present comprehensive maps at single-amino acid resolution of the residues stabilizing the human Gαi1 subunit in nucleotide- and receptor-bound states. We generated these maps by measuring the effects of alanine mutations on the stability of Gαi1 and the rhodopsin-Gαi1 complex. We identified stabilization clusters in the GTPase and helical domains responsible for structural integrity and the conformational changes associated with activation. In activation cluster I, helices α1 and α5 pack against strands β1-β3 to stabilize the nucleotide-bound states. In the receptor-bound state, these interactions are replaced by interactions between α5 and strands β4-β6. Key residues in this cluster are Y320, which is crucial for the stabilization of the receptor-bound state, and F336, which stabilizes nucleotide-bound states. Destabilization of helix α1, caused by rearrangement of this activation cluster, leads to the weakening of the interdomain interface and release of GDP.
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Affiliation(s)
- Dawei Sun
- Laboratory of Biomolecular Research, Paul Scherrer Institute, Villigen, Switzerland
- Department of Biology, Swiss Federal Institute of Technology Zurich, Zurich, Switzerland
| | - Tilman Flock
- Medical Research Council Laboratory of Molecular Biology, Cambridge, United Kingdom
| | - Xavier Deupi
- Laboratory of Biomolecular Research, Paul Scherrer Institute, Villigen, Switzerland
- Condensed Matter Theory Group, Paul Scherrer Institut, Villigen, Switzerland
| | - Shoji Maeda
- Laboratory of Biomolecular Research, Paul Scherrer Institute, Villigen, Switzerland
| | - Milos Matkovic
- Laboratory of Biomolecular Research, Paul Scherrer Institute, Villigen, Switzerland
- Department of Biology, Swiss Federal Institute of Technology Zurich, Zurich, Switzerland
| | - Sandro Mendieta
- Laboratory of Biomolecular Research, Paul Scherrer Institute, Villigen, Switzerland
| | - Daniel Mayer
- Laboratory of Biomolecular Research, Paul Scherrer Institute, Villigen, Switzerland
- Department of Biology, Swiss Federal Institute of Technology Zurich, Zurich, Switzerland
| | - Roger Dawson
- F. Hoffmann-La Roche AG, Pharma Research & Early Development, Discovery Technologies, Basel, Switzerland
| | - Gebhard F X Schertler
- Laboratory of Biomolecular Research, Paul Scherrer Institute, Villigen, Switzerland
- Department of Biology, Swiss Federal Institute of Technology Zurich, Zurich, Switzerland
| | - M Madan Babu
- Medical Research Council Laboratory of Molecular Biology, Cambridge, United Kingdom
| | - Dmitry B Veprintsev
- Laboratory of Biomolecular Research, Paul Scherrer Institute, Villigen, Switzerland
- Department of Biology, Swiss Federal Institute of Technology Zurich, Zurich, Switzerland
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28
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Flock T, Ravarani CNJ, Sun D, Venkatakrishnan AJ, Kayikci M, Tate CG, Veprintsev DB, Babu MM. Universal allosteric mechanism for Gα activation by GPCRs. Nature 2015; 524:173-179. [PMID: 26147082 PMCID: PMC4866443 DOI: 10.1038/nature14663] [Citation(s) in RCA: 252] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2014] [Accepted: 06/16/2015] [Indexed: 12/25/2022]
Abstract
G protein-coupled receptors (GPCRs) allosterically activate heterotrimeric G proteins and trigger GDP release. Given that there are ∼800 human GPCRs and 16 different Gα genes, this raises the question of whether a universal allosteric mechanism governs Gα activation. Here we show that different GPCRs interact with and activate Gα proteins through a highly conserved mechanism. Comparison of Gα with the small G protein Ras reveals how the evolution of short segments that undergo disorder-to-order transitions can decouple regions important for allosteric activation from receptor binding specificity. This might explain how the GPCR-Gα system diversified rapidly, while conserving the allosteric activation mechanism.
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Affiliation(s)
- Tilman Flock
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | | | - Dawei Sun
- Laboratory of Biomolecular Research, Paul Scherrer Institut, Villigen, Switzerland
- Department of Biology, ETH Zurich, Zurich, Switzerland
| | | | - Melis Kayikci
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Christopher G. Tate
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Dmitry B. Veprintsev
- Laboratory of Biomolecular Research, Paul Scherrer Institut, Villigen, Switzerland
- Department of Biology, ETH Zurich, Zurich, Switzerland
| | - M. Madan Babu
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
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29
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Ostermaier MK, Schertler GFX, Standfuss J. Molecular mechanism of phosphorylation-dependent arrestin activation. Curr Opin Struct Biol 2014; 29:143-51. [PMID: 25484000 DOI: 10.1016/j.sbi.2014.07.006] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2014] [Revised: 07/16/2014] [Accepted: 07/18/2014] [Indexed: 12/31/2022]
Abstract
The past years have seen tremendous progress towards understanding how arrestins recognize phosphorylated G protein-coupled receptors (GPCRs). Two arrestin crystal structures, one of a pre-activated splice variant and one bound to a GPCR phosphopeptide, provided insights into the conformational changes upon phosphate recognition. Scanning mutagenesis and spectroscopic studies complete the picture of arrestin activation and receptor binding. Most perspicuous is the C-tail exchange mechanism, by which the C-tail of arrestin is released from its basal conformation and replaced by the phosphorylated GPCR C-terminus. Three positively charged clusters could act as conserved arrestin phosphosensors. Variations in the pattern of phosphorylation in a GPCR and variations within the C-terminus of different GPCRs may encode specificity to arrestin subtypes and particular physiological responses.
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Affiliation(s)
- Martin K Ostermaier
- Laboratory of Biomolecular Research, Paul Scherrer Institute, 5232 Villigen, Switzerland
| | - Gebhard F X Schertler
- Laboratory of Biomolecular Research, Paul Scherrer Institute, 5232 Villigen, Switzerland; Deparment of Biology, ETH Zurich, Wolfgang-Pauli-Str. 27, 8093 Zürich, Switzerland
| | - Joerg Standfuss
- Laboratory of Biomolecular Research, Paul Scherrer Institute, 5232 Villigen, Switzerland.
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30
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Ostermaier MK, Peterhans C, Jaussi R, Deupi X, Standfuss J. Functional map of arrestin-1 at single amino acid resolution. Proc Natl Acad Sci U S A 2014; 111:1825-30. [PMID: 24449856 PMCID: PMC3918777 DOI: 10.1073/pnas.1319402111] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Arrestins function as adapter proteins that mediate G protein-coupled receptor (GPCR) desensitization, internalization, and additional rounds of signaling. Here we have compared binding of the GPCR rhodopsin to 403 mutants of arrestin-1 covering its complete sequence. This comprehensive and unbiased mutagenesis approach provides a functional dimension to the crystal structures of inactive, preactivated p44 and phosphopeptide-bound arrestins and will guide our understanding of arrestin-GPCR complexes. The presented functional map quantitatively connects critical interactions in the polar core and along the C tail of arrestin. A series of amino acids (Phe375, Phe377, Phe380, and Arg382) anchor the C tail in a position that blocks binding of the receptor. Interaction of phosphates in the rhodopsin C terminus with Arg29 controls a C-tail exchange mechanism in which the C tail of arrestin is released and exposes several charged amino acids (Lys14, Lys15, Arg18, Lys20, Lys110, and Lys300) for binding of the phosphorylated receptor C terminus. In addition to this arrestin phosphosensor, our data reveal several patches of amino acids in the finger (Gln69 and Asp73-Met75) and the lariat loops (L249-S252 and Y254) that can act as direct binding interfaces. A stretch of amino acids at the edge of the C domain (Trp194-Ser199, Gly337-Gly340, Thr343, and Thr345) could act as membrane anchor, binding interface for a second rhodopsin, or rearrange closer to the central loops upon complex formation. We discuss these interfaces in the context of experimentally guided docking between the crystal structures of arrestin and light-activated rhodopsin.
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Affiliation(s)
| | | | | | - Xavier Deupi
- Laboratory of Biomolecular Research and
- Condensed Matter Theory Group, Paul Scherrer Institute, 5232 Villigen, Switzerland
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