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Lawrence RE, Shoemaker SR, Deal A, Sangwan S, Anand AA, Wang L, Marqusee S, Walter P. A helical fulcrum in eIF2B coordinates allosteric regulation of stress signaling. Nat Chem Biol 2024; 20:422-431. [PMID: 37945896 PMCID: PMC10972756 DOI: 10.1038/s41589-023-01453-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Accepted: 09/17/2023] [Indexed: 11/12/2023]
Abstract
The integrated stress response (ISR) enables cells to survive a variety of acute stresses, but chronic activation of the ISR underlies age-related diseases. ISR signaling downregulates translation and activates expression of stress-responsive factors that promote return to homeostasis and is initiated by inhibition of the decameric guanine nucleotide exchange factor eIF2B. Conformational and assembly transitions regulate eIF2B activity, but the allosteric mechanisms controlling these dynamic transitions and mediating the therapeutic effects of the small-molecule ISR inhibitor ISRIB are unknown. Using hydrogen-deuterium exchange-mass spectrometry and cryo-electron microscopy, we identified a central α-helix whose orientation allosterically coordinates eIF2B conformation and assembly. Biochemical and cellular signaling assays show that this 'switch-helix' controls eIF2B activity and signaling. In sum, the switch-helix acts as a fulcrum of eIF2B conformational regulation and is a highly conserved actuator of ISR signal transduction. This work uncovers a conserved allosteric mechanism and unlocks new therapeutic possibilities for ISR-linked diseases.
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Affiliation(s)
- Rosalie E Lawrence
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA, USA.
- Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA, USA.
| | - Sophie R Shoemaker
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, USA
| | - Aniliese Deal
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA, USA
- Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA, USA
- Altos Laboratories, Bay Area Institute of Science, Redwood City, CA, USA
| | - Smriti Sangwan
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA, USA
- Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA, USA
| | - Aditya A Anand
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA, USA
- Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA, USA
- Genentech, Inc., South San Francisco, CA, USA
| | - Lan Wang
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA, USA.
- Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA, USA.
- The Hong Kong University of Science and Technology, Hong Kong, Hong Kong.
| | - Susan Marqusee
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, USA.
- Department of Chemistry, University of California, Berkeley, Berkeley, CA, USA.
- Chan Zuckerberg Biohub, San Francisco, CA, USA.
- California Institute for Quantitative Biosciences, University of California, Berkeley, Berkeley, CA, USA.
| | - Peter Walter
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA, USA.
- Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA, USA.
- Altos Laboratories, Bay Area Institute of Science, Redwood City, CA, USA.
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2
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Blikstad C, Dugan EJ, Laughlin TG, Turnšek JB, Liu MD, Shoemaker SR, Vogiatzi N, Remis JP, Savage DF. Identification of a carbonic anhydrase-Rubisco complex within the alpha-carboxysome. Proc Natl Acad Sci U S A 2023; 120:e2308600120. [PMID: 37862384 PMCID: PMC10614612 DOI: 10.1073/pnas.2308600120] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Accepted: 08/28/2023] [Indexed: 10/22/2023] Open
Abstract
Carboxysomes are proteinaceous organelles that encapsulate key enzymes of CO2 fixation-Rubisco and carbonic anhydrase-and are the centerpiece of the bacterial CO2 concentrating mechanism (CCM). In the CCM, actively accumulated cytosolic bicarbonate diffuses into the carboxysome and is converted to CO2 by carbonic anhydrase, producing a high CO2 concentration near Rubisco and ensuring efficient carboxylation. Self-assembly of the α-carboxysome is orchestrated by the intrinsically disordered scaffolding protein, CsoS2, which interacts with both Rubisco and carboxysomal shell proteins, but it is unknown how the carbonic anhydrase, CsoSCA, is incorporated into the α-carboxysome. Here, we present the structural basis of carbonic anhydrase encapsulation into α-carboxysomes from Halothiobacillus neapolitanus. We find that CsoSCA interacts directly with Rubisco via an intrinsically disordered N-terminal domain. A 1.98 Å single-particle cryoelectron microscopy structure of Rubisco in complex with this peptide reveals that CsoSCA binding is predominantly mediated by a network of hydrogen bonds. CsoSCA's binding site overlaps with that of CsoS2, but the two proteins utilize substantially different motifs and modes of binding, revealing a plasticity of the Rubisco binding site. Our results advance the understanding of carboxysome biogenesis and highlight the importance of Rubisco, not only as an enzyme but also as a central hub for mediating assembly through protein interactions.
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Affiliation(s)
- Cecilia Blikstad
- Department of Molecular and Cell Biology, University of California, Berkeley, CA94720
- Department of Chemistry - Ångström Laboratory, Uppsala University, Uppsala75120, Sweden
| | - Eli J. Dugan
- Department of Molecular and Cell Biology, University of California, Berkeley, CA94720
| | - Thomas G. Laughlin
- Department of Molecular and Cell Biology, University of California, Berkeley, CA94720
| | - Julia B. Turnšek
- Department of Molecular and Cell Biology, University of California, Berkeley, CA94720
| | - Mira D. Liu
- Department of Chemistry, University of California, Berkeley, CA94720
| | - Sophie R. Shoemaker
- Department of Molecular and Cell Biology, University of California, Berkeley, CA94720
| | - Nikoleta Vogiatzi
- Department of Chemistry - Ångström Laboratory, Uppsala University, Uppsala75120, Sweden
| | - Jonathan P. Remis
- California Institute for Quantitative Biosciences, University of California, Berkeley, CA94720
| | - David F. Savage
- Department of Molecular and Cell Biology, University of California, Berkeley, CA94720
- HHMI, University of California, Berkeley, CA94720
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Silva RP, Huang Y, Nguyen AW, Hsieh CL, Olaluwoye OS, Kaoud TS, Wilen RE, Qerqez AN, Park JG, Khalil AM, Azouz LR, Le KC, Bohanon AL, DiVenere AM, Liu Y, Lee AG, Amengor DA, Shoemaker SR, Costello SM, Padlan EA, Marqusee S, Martinez-Sobrido L, Dalby KN, D'Arcy S, McLellan JS, Maynard JA. Identification of a conserved S2 epitope present on spike proteins from all highly pathogenic coronaviruses. eLife 2023; 12:e83710. [PMID: 36942851 PMCID: PMC10030117 DOI: 10.7554/elife.83710] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Accepted: 03/04/2023] [Indexed: 03/23/2023] Open
Abstract
To address the ongoing SARS-CoV-2 pandemic and prepare for future coronavirus outbreaks, understanding the protective potential of epitopes conserved across SARS-CoV-2 variants and coronavirus lineages is essential. We describe a highly conserved, conformational S2 domain epitope present only in the prefusion core of β-coronaviruses: SARS-CoV-2 S2 apex residues 980-1006 in the flexible hinge. Antibody RAY53 binds the native hinge in MERS-CoV and SARS-CoV-2 spikes on the surface of mammalian cells and mediates antibody-dependent cellular phagocytosis and cytotoxicity against SARS-CoV-2 spike in vitro. Hinge epitope mutations that ablate antibody binding compromise pseudovirus infectivity, but changes elsewhere that affect spike opening dynamics, including those found in Omicron BA.1, occlude the epitope and may evade pre-existing serum antibodies targeting the S2 core. This work defines a third class of S2 antibody while providing insights into the potency and limitations of S2 core epitope targeting.
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Affiliation(s)
- Rui P Silva
- Department of Molecular Biosciences, The University of Texas at AustinAustinUnited States
| | - Yimin Huang
- Department of Molecular Biosciences, The University of Texas at AustinAustinUnited States
| | - Annalee W Nguyen
- Department of Chemical Engineering, The University of Texas at AustinAustinUnited States
| | - Ching-Lin Hsieh
- Department of Molecular Biosciences, The University of Texas at AustinAustinUnited States
| | - Oladimeji S Olaluwoye
- Department of Chemistry and Biochemistry, The University of Texas at DallasDallasUnited States
| | - Tamer S Kaoud
- Division of Chemical Biology and Medicinal Chemistry, The University of Texas at AustinAustinUnited States
| | - Rebecca E Wilen
- Department of Chemical Engineering, The University of Texas at AustinAustinUnited States
| | - Ahlam N Qerqez
- Department of Chemical Engineering, The University of Texas at AustinAustinUnited States
| | - Jun-Gyu Park
- Texas Biomedical Research InstituteSan AntonioUnited States
- Laboratory of Veterinary Zoonosis, College of Veterinary Medicine, Chonnam National UniversityGwangjuRepublic of Korea
| | - Ahmed M Khalil
- Texas Biomedical Research InstituteSan AntonioUnited States
| | - Laura R Azouz
- Department of Chemical Engineering, The University of Texas at AustinAustinUnited States
| | - Kevin C Le
- Department of Chemical Engineering, The University of Texas at AustinAustinUnited States
| | - Amanda L Bohanon
- Department of Molecular Biosciences, The University of Texas at AustinAustinUnited States
| | - Andrea M DiVenere
- Department of Chemical Engineering, The University of Texas at AustinAustinUnited States
| | - Yutong Liu
- Department of Chemical Engineering, The University of Texas at AustinAustinUnited States
| | - Alison G Lee
- Department of Molecular Biosciences, The University of Texas at AustinAustinUnited States
| | - Dzifa A Amengor
- Department of Molecular Biosciences, The University of Texas at AustinAustinUnited States
| | - Sophie R Shoemaker
- Department of Molecular and Cell Biology, University of California, BerkeleyBerkeleyUnited States
| | - Shawn M Costello
- Biophysics Graduate Program, University of California, BerkeleyBerkeleyUnited States
| | | | - Susan Marqusee
- Department of Molecular and Cell Biology, University of California, BerkeleyBerkeleyUnited States
- Department of Chemistry, University of California, BerkeleyBerkeleyUnited States
| | | | - Kevin N Dalby
- Division of Chemical Biology and Medicinal Chemistry, The University of Texas at AustinAustinUnited States
| | - Sheena D'Arcy
- Department of Chemistry and Biochemistry, The University of Texas at DallasDallasUnited States
| | - Jason S McLellan
- Department of Molecular Biosciences, The University of Texas at AustinAustinUnited States
- LaMontagne Center for Infectious Diseases, The University of Texas at AustinAustinUnited States
| | - Jennifer A Maynard
- Department of Chemical Engineering, The University of Texas at AustinAustinUnited States
- LaMontagne Center for Infectious Diseases, The University of Texas at AustinAustinUnited States
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Affiliation(s)
- Sophie R Shoemaker
- Molecular and Cell Biology, University of California Berkeley, Berkeley, CA, USA
| | - Tina X Li
- Molecular and Cell Biology, University of California Berkeley, Berkeley, CA, USA
| | - Wesley Wu
- Chan Zuckerberg Biohub, San Francisco, CA, USA
| | - John E Pak
- Chan Zuckerberg Biohub, San Francisco, CA, USA
| | - Susan Marqusee
- Molecular and Cell Biology, University of California Berkeley, Berkeley, CA, USA; Chemistry, University of California Berkeley, Berkeley, CA, USA
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5
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Hobbs HT, Shah NH, Shoemaker SR, Amacher JF, Marqusee S, Kuriyan J. Saturation mutagenesis of a predicted ancestral Syk-family kinase. Protein Sci 2022; 31:e4411. [PMID: 36173161 PMCID: PMC9601881 DOI: 10.1002/pro.4411] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2022] [Revised: 06/27/2022] [Accepted: 07/25/2022] [Indexed: 11/08/2022]
Abstract
Many tyrosine kinases cannot be expressed readily in Escherichia coli, limiting facile production of these proteins for biochemical experiments. We used ancestral sequence reconstruction to generate a spleen tyrosine kinase (Syk) variant that can be expressed in bacteria and purified in soluble form, unlike the human members of this family (Syk and zeta-chain-associated protein kinase of 70 kDa [ZAP-70]). The catalytic activity, substrate specificity, and regulation by phosphorylation of this Syk variant are similar to the corresponding properties of human Syk and ZAP-70. Taking advantage of the ability to express this novel Syk-family kinase in bacteria, we developed a two-hybrid assay that couples the growth of E. coli in the presence of an antibiotic to successful phosphorylation of a bait peptide by the kinase. Using this assay, we screened a site-saturation mutagenesis library of the kinase domain of this reconstructed Syk-family kinase. Sites of loss-of-function mutations identified in the screen correlate well with residues established previously as critical to function and/or structure in protein kinases. We also identified activating mutations in the regulatory hydrophobic spine and activation loop, which are within key motifs involved in kinase regulation. Strikingly, one mutation in an ancestral Syk-family variant increases the soluble expression of the protein by 75-fold. Thus, through ancestral sequence reconstruction followed by deep mutational scanning, we have generated Syk-family kinase variants that can be expressed in bacteria with very high yield.
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Affiliation(s)
- Helen T. Hobbs
- Department of ChemistryUniversity of CaliforniaBerkeleyCaliforniaUSA
- Department of Biomedical EngineeringUniversity of CaliforniaIrvineCaliforniaUSA
| | - Neel H. Shah
- Department of ChemistryColumbia UniversityNew YorkNew YorkUSA
| | - Sophie R. Shoemaker
- Department of Molecular and Cell BiologyUniversity of CaliforniaBerkeleyCaliforniaUSA
| | - Jeanine F. Amacher
- Department of ChemistryWestern Washington UniversityBellinghamWashingtonUSA
| | - Susan Marqusee
- Department of ChemistryUniversity of CaliforniaBerkeleyCaliforniaUSA
- Department of Molecular and Cell BiologyUniversity of CaliforniaBerkeleyCaliforniaUSA
- California Institute for Quantitative BiosciencesUniversity of CaliforniaBerkeleyCaliforniaUSA
| | - John Kuriyan
- Department of ChemistryUniversity of CaliforniaBerkeleyCaliforniaUSA
- Department of Molecular and Cell BiologyUniversity of CaliforniaBerkeleyCaliforniaUSA
- California Institute for Quantitative BiosciencesUniversity of CaliforniaBerkeleyCaliforniaUSA
- Howard Hughes Medical InstituteUniversity of CaliforniaBerkeleyCaliforniaUSA
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6
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Costello SM, Shoemaker SR, Hobbs HT, Nguyen AW, Hsieh CL, Maynard JA, McLellan JS, Pak JE, Marqusee S. The SARS-CoV-2 spike reversibly samples an open-trimer conformation exposing novel epitopes. Nat Struct Mol Biol 2022; 29:229-238. [PMID: 35236990 PMCID: PMC9007726 DOI: 10.1038/s41594-022-00735-5] [Citation(s) in RCA: 58] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Accepted: 01/21/2022] [Indexed: 11/09/2022]
Abstract
Current COVID-19 vaccines and many clinical diagnostics are based on the structure and function of the SARS-CoV-2 spike ectodomain. Using hydrogen-deuterium exchange monitored by mass spectrometry, we have uncovered that, in addition to the prefusion structure determined by cryo-electron microscopy, this protein adopts an alternative conformation that interconverts slowly with the canonical prefusion structure. This new conformation-an open trimer-contains easily accessible receptor-binding domains. It exposes the conserved trimer interface buried in the prefusion conformation, thus exposing potential epitopes for pan-coronavirus antibody and ligand recognition. The population of this state and kinetics of interconversion are modulated by temperature, receptor binding, antibody binding, and sequence variants observed in the natural population. Knowledge of the structure and populations of this conformation will help improve existing diagnostics, therapeutics, and vaccines.
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Affiliation(s)
- Shawn M Costello
- Biophysics Graduate Program, University of California, Berkeley, CA, USA
| | - Sophie R Shoemaker
- Department of Molecular and Cell Biology, University of California, Berkeley, CA, USA
| | - Helen T Hobbs
- Department of Chemistry, University of California, Berkeley, CA, USA
| | - Annalee W Nguyen
- Department of Chemical Engineering, The University of Texas at Austin, Austin, TX, USA
| | - Ching-Lin Hsieh
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX, USA
| | - Jennifer A Maynard
- Department of Chemical Engineering, The University of Texas at Austin, Austin, TX, USA
| | - Jason S McLellan
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX, USA
| | - John E Pak
- Chan Zuckerberg Biohub, San Francisco, CA, USA
| | - Susan Marqusee
- Department of Molecular and Cell Biology, University of California, Berkeley, CA, USA.
- Department of Chemistry, University of California, Berkeley, CA, USA.
- Chan Zuckerberg Biohub, San Francisco, CA, USA.
- California Institute for Quantitative Biosciences, University of California, Berkeley, CA, USA.
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Shoemaker SR, Zhang Y, O'Brien T, Tantillo D, Siegel JB. Hybrid Quantum Mechanics/Rosetta Modeling Mechanistic Study of a Terpene Synthase. Biophys J 2020. [DOI: 10.1016/j.bpj.2019.11.1719] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
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Chum AP, Shoemaker SR, Fleming PJ, Fleming KG. Plasticity and transient binding are key ingredients of the periplasmic chaperone network. Protein Sci 2019; 28:1340-1349. [PMID: 31074917 DOI: 10.1002/pro.3641] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Revised: 05/05/2019] [Accepted: 05/06/2019] [Indexed: 01/29/2023]
Abstract
SurA, Skp, FkpA, and DegP constitute a chaperone network that ensures biogenesis of outer membrane proteins (OMPs) in Gram-negative bacteria. Both Skp and FkpA are holdases that prevent the self-aggregation of unfolded OMPs, whereas SurA accelerates folding and DegP is a protease. None of these chaperones is essential, and we address here how functional plasticity is manifested in nine known null strains. Using a comprehensive computational model of this network termed OMPBioM, our results suggest that a threshold level of steady state holdase occupancy by chaperones is required, but the cell is agnostic to the specific holdase molecule fulfilling this function. In addition to its foldase activity, SurA moonlights as a holdase when there is no expression of Skp and FkpA. We further interrogate the importance of chaperone-client complex lifetime by conducting simulations using lifetime values for Skp complexes that range in length by six orders of magnitude. This analysis suggests that transient occupancy of durations much shorter than the Escherichia coli doubling time is required. We suggest that fleeting chaperone occupancy facilitates rapid sampling of the periplasmic conditions, which ensures that the cell can be adept at responding to environmental changes. Finally, we calculated the network effects of adding multivalency by computing populations that include two Skp trimers per unfolded OMP. We observe only modest perturbations to the system. Overall, this quantitative framework of chaperone-protein interactions in the periplasm demonstrates robust plasticity due to its dynamic binding and unbinding behavior.
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Affiliation(s)
- Aaron P Chum
- T.C. Jenkins Department of Biophysics, Johns Hopkins University, Baltimore, Maryland
| | - Sophie R Shoemaker
- T.C. Jenkins Department of Biophysics, Johns Hopkins University, Baltimore, Maryland
| | - Patrick J Fleming
- T.C. Jenkins Department of Biophysics, Johns Hopkins University, Baltimore, Maryland
| | - Karen G Fleming
- T.C. Jenkins Department of Biophysics, Johns Hopkins University, Baltimore, Maryland
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