1
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Klawa SJ, Lee M, Riker KD, Jian T, Wang Q, Gao Y, Daly ML, Bhonge S, Childers WS, Omosun TO, Mehta AK, Lynn DG, Freeman R. Uncovering supramolecular chirality codes for the design of tunable biomaterials. Nat Commun 2024; 15:788. [PMID: 38278785 PMCID: PMC10817930 DOI: 10.1038/s41467-024-45019-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 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: 08/08/2023] [Accepted: 01/12/2024] [Indexed: 01/28/2024] Open
Abstract
In neurodegenerative diseases, polymorphism and supramolecular assembly of β-sheet amyloids are implicated in many different etiologies and may adopt either a left- or right-handed supramolecular chirality. Yet, the underlying principles of how sequence regulates supramolecular chirality remains unknown. Here, we characterize the sequence specificity of the central core of amyloid-β 42 and design derivatives which enable chirality inversion at biologically relevant temperatures. We further find that C-terminal modifications can tune the energy barrier of a left-to-right chiral inversion. Leveraging this design principle, we demonstrate how temperature-triggered chiral inversion of peptides hosting therapeutic payloads modulates the dosed release of an anticancer drug. These results suggest a generalizable approach for fine-tuning supramolecular chirality that can be applied in developing treatments to regulate amyloid morphology in neurodegeneration as well as in other disease states.
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Affiliation(s)
- Stephen J Klawa
- Department of Applied Physical Sciences, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Michelle Lee
- Department of Chemistry, Emory University, Atlanta, GA, 30322, USA
| | - Kyle D Riker
- Department of Applied Physical Sciences, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Tengyue Jian
- Department of Applied Physical Sciences, University of North Carolina, Chapel Hill, NC, 27599, USA
- Broad Pharm, San Diego, California, 92121, USA
| | - Qunzhao Wang
- Department of Applied Physical Sciences, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Yuan Gao
- Department of Applied Physical Sciences, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Margaret L Daly
- Department of Applied Physical Sciences, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Shreeya Bhonge
- Department of Applied Physical Sciences, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - W Seth Childers
- Department of Chemistry, Emory University, Atlanta, GA, 30322, USA
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA, 15260, USA
| | - Tolulope O Omosun
- Department of Chemistry, Emory University, Atlanta, GA, 30322, USA
- U.S. Department of Justice, Chicago, IL, 60603, USA
| | - Anil K Mehta
- Department of Chemistry, Emory University, Atlanta, GA, 30322, USA
- The National High Magnetic Field Laboratory, University of Florida, Gainesville, FL, 32611, USA
| | - David G Lynn
- Department of Chemistry, Emory University, Atlanta, GA, 30322, USA.
- Department of Biology, Emory University, Atlanta, GA, 30322, USA.
| | - Ronit Freeman
- Department of Applied Physical Sciences, University of North Carolina, Chapel Hill, NC, 27599, USA.
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2
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Nandana V, Rathnayaka-Mudiyanselage IW, Muthunayake NS, Hatami A, Mousseau CB, Ortiz-Rodríguez LA, Vaishnav J, Collins M, Gega A, Mallikaarachchi KS, Yassine H, Ghosh A, Biteen JS, Zhu Y, Champion MM, Childers WS, Schrader JM. The BR-body proteome contains a complex network of protein-protein and protein-RNA interactions. Cell Rep 2023; 42:113229. [PMID: 37815915 PMCID: PMC10842194 DOI: 10.1016/j.celrep.2023.113229] [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: 02/17/2023] [Revised: 07/16/2023] [Accepted: 09/22/2023] [Indexed: 10/12/2023] Open
Abstract
Bacterial ribonucleoprotein bodies (BR-bodies) are non-membrane-bound structures that facilitate mRNA decay by concentrating mRNA substrates with RNase E and the associated RNA degradosome machinery. However, the full complement of proteins enriched in BR-bodies has not been defined. Here, we define the protein components of BR-bodies through enrichment of the bodies followed by mass spectrometry-based proteomic analysis. We find 111 BR-body-enriched proteins showing that BR-bodies are more complex than previously assumed. We identify five BR-body-enriched proteins that undergo RNA-dependent phase separation in vitro with a complex network of condensate mixing. We observe that some RNP condensates co-assemble with preferred directionality, suggesting that RNA may be trafficked through RNP condensates in an ordered manner to facilitate mRNA processing/decay, and that some BR-body-associated proteins have the capacity to dissolve the condensate. Altogether, these results suggest that a complex network of protein-protein and protein-RNA interactions controls BR-body phase separation and RNA processing.
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Affiliation(s)
- Vidhyadhar Nandana
- Department of Biological Sciences, Wayne State University, Detroit, MI 48202, USA
| | - Imalka W Rathnayaka-Mudiyanselage
- Department of Biological Sciences, Wayne State University, Detroit, MI 48202, USA; Department of Chemistry, Wayne State University, Detroit, MI 48202, USA
| | | | - Ali Hatami
- Department of Chemical Engineering and Materials Science, Wayne State University, Detroit, MI 48202, USA
| | - C Bruce Mousseau
- Department of Chemistry, University of Notre Dame, Notre Dame, IN 46556, USA
| | | | - Jamuna Vaishnav
- Department of Chemical Engineering and Materials Science, Wayne State University, Detroit, MI 48202, USA
| | - Michael Collins
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Alisa Gega
- Department of Biological Sciences, Wayne State University, Detroit, MI 48202, USA
| | | | - Hadi Yassine
- Department of Biological Sciences, Wayne State University, Detroit, MI 48202, USA
| | - Aishwarya Ghosh
- Department of Biological Sciences, Wayne State University, Detroit, MI 48202, USA
| | - Julie S Biteen
- Department of Chemistry, University of Michigan, Ann Arbor, MI 48109, USA
| | - Yingxi Zhu
- Department of Chemical Engineering and Materials Science, Wayne State University, Detroit, MI 48202, USA
| | - Matthew M Champion
- Department of Chemistry, University of Notre Dame, Notre Dame, IN 46556, USA
| | - W Seth Childers
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Jared M Schrader
- Department of Biological Sciences, Wayne State University, Detroit, MI 48202, USA.
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3
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Collins MJ, Tomares DT, Nandana V, Schrader JM, Childers WS. RNase E biomolecular condensates stimulate PNPase activity. Sci Rep 2023; 13:12937. [PMID: 37558691 PMCID: PMC10412687 DOI: 10.1038/s41598-023-39565-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [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: 08/11/2022] [Accepted: 07/27/2023] [Indexed: 08/11/2023] Open
Abstract
Bacterial Ribonucleoprotein bodies (BR-bodies) play an essential role in organizing RNA degradation via phase separation in the cytoplasm of bacteria. BR-bodies mediate multi-step mRNA decay through the concerted activity of the endoribonuclease RNase E coupled with the 3'-5' exoribonuclease Polynucleotide Phosphorylase (PNPase). In vivo, studies indicated that the loss of PNPase recruitment into BR-bodies led to a significant build-up of RNA decay intermediates in Caulobacter crescentus. However, it remained unclear whether this is due to a lack of colocalized PNPase and RNase E within BR-bodies or whether PNPase's activity is stimulated within the BR-body. We reconstituted RNase E's C-terminal domain with PNPase towards a minimal BR-body in vitro to distinguish these possibilities. We found that PNPase's catalytic activity is accelerated when colocalized within the RNase E biomolecular condensates, partly due to scaffolding and mass action effects. In contrast, disruption of the RNase E-PNPase protein-protein interaction led to a loss of PNPase recruitment into the RNase E condensates and a loss of ribonuclease rate enhancement. We also found that RNase E's unique biomolecular condensate environment tuned PNPase's substrate specificity for poly(A) over poly(U). Intriguingly, a critical PNPase reactant, phosphate, reduces RNase E phase separation both in vitro and in vivo. This regulatory feedback ensures that under limited phosphate resources, PNPase activity is enhanced by recruitment into RNase E's biomolecular condensates.
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Affiliation(s)
- Michael J Collins
- Department of Chemistry, University of Pittsburgh, Pittsburgh, 15260, USA
| | - Dylan T Tomares
- Department of Chemistry, University of Pittsburgh, Pittsburgh, 15260, USA
| | - Vidhyadhar Nandana
- Department of Biological Sciences, Wayne State University, Detroit, MI, 48202, USA
| | - Jared M Schrader
- Department of Biological Sciences, Wayne State University, Detroit, MI, 48202, USA
| | - W Seth Childers
- Department of Chemistry, University of Pittsburgh, Pittsburgh, 15260, USA.
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4
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Nandana V, Rathnayaka-Mudiyanselage IW, Muthunayak NS, Hatami A, Mousseau CB, Ortiz-Rodríguez LA, Vaishnav J, Collins M, Gega A, Mallikaarachchi KS, Yassine H, Ghosh A, Biteen JS, Zhu Y, Champion MM, Childers WS, Schrader JM. The BR-body proteome contains a complex network of protein-protein and protein-RNA interactions. bioRxiv 2023:2023.01.18.524314. [PMID: 36712072 PMCID: PMC9882336 DOI: 10.1101/2023.01.18.524314] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Bacterial RNP bodies (BR-bodies) are non-membrane-bound structures that facilitate mRNA decay by concentrating mRNA substrates with RNase E and the associated RNA degradosome machinery. However, the full complement of proteins enriched in BR-bodies has not been defined. Here we define the protein components of BR-bodies through enrichment of the bodies followed by mass spectrometry-based proteomic analysis. We found 111 BR-body enriched proteins, including several RNA binding proteins, many of which are also recruited directly to in vitro reconstituted RNase E droplets, showing BR-bodies are more complex than previously assumed. While most BR-body enriched proteins that were tested cannot phase separate, we identified five that undergo RNA-dependent phase separation in vitro, showing other RNP condensates interface with BR-bodies. RNA degradosome protein clients are recruited more strongly to RNase E droplets than droplets of other RNP condensates, implying that client specificity is largely achieved through direct protein-protein interactions. We observe that some RNP condensates assemble with preferred directionally, suggesting that RNA may be trafficked through RNP condensates in an ordered manner to facilitate mRNA processing/decay, and that some BR-body associated proteins have the capacity to dissolve the condensate. Finally, we find that RNA dramatically stimulates the rate of RNase E phase separation in vitro, explaining the dissolution of BR-bodies after cellular mRNA depletion observed previously. Altogether, these results suggest that a complex network of protein-protein and protein-RNA interactions controls BR-body phase separation and RNA processing.
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Affiliation(s)
- V Nandana
- Wayne State University, Department of Biological Sciences, Detroit, MI
| | - I W Rathnayaka-Mudiyanselage
- Wayne State University, Department of Biological Sciences, Detroit, MI
- Wayne State University, Department of Chemistry, Detroit, MI
| | - N S Muthunayak
- Wayne State University, Department of Biological Sciences, Detroit, MI
| | - A Hatami
- Wayne State University, Department of Chemical Engineering and Materials Science, Detroit, MI
| | - C B Mousseau
- University of Notre Dame, Department of Chemistry, Notre Dame, IN
| | | | - J Vaishnav
- Wayne State University, Department of Chemical Engineering and Materials Science, Detroit, MI
| | - M Collins
- University of Pittsburgh, Department of Chemistry, Pittsburgh, PA
| | - A Gega
- Wayne State University, Department of Biological Sciences, Detroit, MI
| | | | - H Yassine
- Wayne State University, Department of Biological Sciences, Detroit, MI
| | - A Ghosh
- Wayne State University, Department of Biological Sciences, Detroit, MI
| | - J S Biteen
- University of Michigan, Department of Chemistry, Ann Arbor, MI
| | - Y Zhu
- Wayne State University, Department of Chemical Engineering and Materials Science, Detroit, MI
| | - M M Champion
- University of Notre Dame, Department of Chemistry, Notre Dame, IN
| | - W S Childers
- University of Pittsburgh, Department of Chemistry, Pittsburgh, PA
| | - J M Schrader
- Wayne State University, Department of Biological Sciences, Detroit, MI
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5
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Lu N, Duvall SW, Zhao G, Kowallis KA, Zhang C, Tan W, Sun J, Petitjean HN, Tomares DT, Zhao GP, Childers WS, Zhao W. Scaffold-Scaffold Interaction Facilitates Cell Polarity Development in Caulobacter crescentus. mBio 2023; 14:e0321822. [PMID: 36971555 PMCID: PMC10127582 DOI: 10.1128/mbio.03218-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/29/2023] Open
Abstract
Caulobacter crescentus
is a well-established bacterial model to study asymmetric cell division for decades. During cell development, the polarization of scaffold protein PopZ from monopolar to bipolar plays a central role in
C. crescentus
asymmetric cell division.
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6
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Tan W, Cheng S, Li Y, Li XY, Lu N, Sun J, Tang G, Yang Y, Cai K, Li X, Ou X, Gao X, Zhao GP, Childers WS, Zhao W. Phase separation modulates the assembly and dynamics of a polarity-related scaffold-signaling hub. Nat Commun 2022; 13:7181. [PMID: 36418326 PMCID: PMC9684454 DOI: 10.1038/s41467-022-35000-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Accepted: 11/14/2022] [Indexed: 11/26/2022] Open
Abstract
Asymmetric cell division (ACD) produces morphologically and behaviorally distinct cells and is the primary way to generate cell diversity. In the model bacterium Caulobacter crescentus, the polarization of distinct scaffold-signaling hubs at the swarmer and stalked cell poles constitutes the basis of ACD. However, mechanisms involved in the formation of these hubs remain elusive. Here, we show that a swarmer-cell-pole scaffold, PodJ, forms biomolecular condensates both in vitro and in living cells via phase separation. The coiled-coil 4-6 and the intrinsically disordered regions are the primary domains that contribute to biomolecular condensate generation and signaling protein recruitment in PodJ. Moreover, a negative regulation of PodJ phase separation by the stalked-cell-pole scaffold protein SpmX is revealed. SpmX impedes PodJ cell-pole accumulation and affects its recruitment ability. Together, by modulating the assembly and dynamics of scaffold-signaling hubs, phase separation may serve as a general biophysical mechanism that underlies the regulation of ACD in bacteria and other organisms.
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Affiliation(s)
- Wei Tan
- grid.458489.c0000 0001 0483 7922CAS Key Laboratory of Quantitative Engineering Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055 China
| | - Sihua Cheng
- grid.458489.c0000 0001 0483 7922CAS Key Laboratory of Quantitative Engineering Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055 China
| | - Yingying Li
- grid.458489.c0000 0001 0483 7922CAS Key Laboratory of Quantitative Engineering Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055 China
| | - Xiao-Yang Li
- grid.458489.c0000 0001 0483 7922CAS Key Laboratory of Quantitative Engineering Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055 China ,grid.256922.80000 0000 9139 560XDepartment of Pharmacy, School of Life Sciences, Henan University, Kaifeng, 475004 China
| | - Ning Lu
- grid.458489.c0000 0001 0483 7922CAS Key Laboratory of Quantitative Engineering Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055 China
| | - Jingxian Sun
- grid.458489.c0000 0001 0483 7922CAS Key Laboratory of Quantitative Engineering Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055 China
| | - Guiyue Tang
- grid.458489.c0000 0001 0483 7922CAS Key Laboratory of Quantitative Engineering Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055 China
| | - Yujiao Yang
- grid.9227.e0000000119573309CAS Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200032 China ,grid.410726.60000 0004 1797 8419University of Chinese Academy of Sciences, Beijing, 100049 China
| | - Kezhu Cai
- grid.458489.c0000 0001 0483 7922CAS Key Laboratory of Quantitative Engineering Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055 China ,grid.263817.90000 0004 1773 1790Department of Materials Science and Engineering, School of Engineering, Southern University of Science and Technology, Shenzhen, 518055 China
| | - Xuefei Li
- grid.458489.c0000 0001 0483 7922CAS Key Laboratory of Quantitative Engineering Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055 China
| | - Xijun Ou
- grid.263817.90000 0004 1773 1790Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, 518055 China
| | - Xiang Gao
- grid.458489.c0000 0001 0483 7922CAS Key Laboratory of Quantitative Engineering Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055 China
| | - Guo-Ping Zhao
- grid.458489.c0000 0001 0483 7922CAS Key Laboratory of Quantitative Engineering Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055 China ,grid.9227.e0000000119573309CAS Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200032 China ,grid.8547.e0000 0001 0125 2443State Key Lab of Genetic Engineering & Institutes of Biomedical Sciences, Department of Microbiology and Microbial Engineering, School of Life Sciences, Fudan University, Shanghai, 200433 China
| | - W. Seth Childers
- grid.21925.3d0000 0004 1936 9000Department of Chemistry, University of Pittsburgh, Pittsburgh, PA 15260 USA
| | - Wei Zhao
- grid.458489.c0000 0001 0483 7922CAS Key Laboratory of Quantitative Engineering Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055 China
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7
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Tomares DT, Whitlock S, Mann M, DiBernardo E, Childers WS. Repurposing Peptide Nanomaterials as Synthetic Biomolecular Condensates in Bacteria. ACS Synth Biol 2022; 11:2154-2162. [PMID: 35658421 DOI: 10.1021/acssynbio.2c00078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Peptide nanomaterials exhibit diverse applications in vitro, such as drug delivery. Here, we consider the utility of de novo peptide nanomaterials to organize biochemistry within the bacterial cytoplasm. Toward this goal, we discovered that ABC coiled-coil triblock peptides form gel-like biomolecular condensates with a csat of 10 μM in addition to their well-known hydrogel-forming capabilities. Expression of the coiled-coil triblock peptides in bacteria leads to cell pole accumulation via a nucleoid occlusion mechanism. We then provide a proof of principle that these synthetic biomolecular condensates could sequester clients at the cell pole. Finally, we demonstrate that triblock peptides and another biomolecular condensate, RNase E, phase-separate as distinct protein-rich assemblies in vitro and in vivo. These results reveal the potential of using peptide nanomaterials to divide the bacterial cytoplasm into distinct subcellular zones with future metabolic engineering and synthetic biology applications.
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Affiliation(s)
- Dylan T Tomares
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - Sara Whitlock
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - Matthew Mann
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - Emma DiBernardo
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - W Seth Childers
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
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8
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Yang X, Kowallis KA, Childers WS. Protein engineering strategies to stimulate the functions of bacterial pseudokinases. Methods Enzymol 2022; 667:275-302. [PMID: 35525544 DOI: 10.1016/bs.mie.2022.03.030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Enzymes orchestrate an array of concerted functions that often culminate in the chemical conversion of substrates into products. In the bacterial kingdom, histidine kinases autophosphorylate, then transfer that phosphate to a second protein called a response regulator. Bacterial genomes can encode large numbers of histidine kinases that provide surveillance of environmental and cytosolic stresses through signal stimulation of histidine kinase activity. Pseudokinases lack these hallmark catalytic functions but often retain binding interactions and allostery. Characterization of bacterial pseudokinases then takes a fundamentally different approach than their enzymatic counterparts. Here we discuss models for how bacterial pseudokinases can utilize protein-protein interactions and allostery to serve as crucial signaling pathway regulators. Then we describe a protein engineering strategy to interrogate these models, emphasizing how signals flow within bacterial pseudokinases. This description includes design considerations, cloning strategies, and the purification of leucine zippers fused to pseudokinases. We then describe two assays to interrogate this approach. First is a C. crescentus swarm plate assay to track motility phenotypes related to a bacterial pseudokinase. Second is an in vitro coupled-enzyme assay that can be applied to test if and how a pseudokinase regulates an active kinase. Together these approaches provide a blueprint for dissecting the mechanisms of cryptic bacterial pseudokinases.
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Affiliation(s)
- Xiaole Yang
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA, United States
| | - Kimberly A Kowallis
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA, United States
| | - W Seth Childers
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA, United States.
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9
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Zhang C, Zhao W, Duvall SW, Kowallis KA, Childers WS. Regulation of the activity of bacterial histidine kinase PleC by the scaffolding protein PodJ. J Biol Chem 2022; 298:101683. [PMID: 35124010 PMCID: PMC8980812 DOI: 10.1016/j.jbc.2022.101683] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Accepted: 01/31/2022] [Indexed: 12/11/2022] Open
Abstract
Scaffolding proteins can customize the response of signaling networks to support cell development and behaviors. PleC is a bifunctional histidine kinase whose signaling activity coordinates asymmetric cell division to yield a motile swarmer cell and a stalked cell in the gram-negative bacterium Caulobacter crescentus. Past studies have shown that PleC’s switch in activity from kinase to phosphatase correlates with a change in its subcellular localization pattern from diffuse to localized at the new cell pole. Here we investigated how the bacterial scaffolding protein PodJ regulates the subcellular positioning and activity of PleC. We reconstituted the PleC-PodJ signaling complex through both heterologous expressions in Escherichia coli and in vitro studies. In vitro, PodJ phase separates as a biomolecular condensate that recruits PleC and inhibits its kinase activity. We also constructed an in vivo PleC-CcaS chimeric histidine kinase reporter assay and demonstrated using this method that PodJ leverages its intrinsically disordered region to bind to PleC’s PAS sensory domain and regulate PleC-CcaS signaling. Regulation of the PleC-CcaS was most robust when PodJ was concentrated at the cell poles and was dependent on the allosteric coupling between PleC-CcaS’s PAS sensory domain and its downstream histidine kinase domain. In conclusion, our in vitro biochemical studies suggest that PodJ phase separation may be coupled to changes in PleC enzymatic function. We propose that this coupling of phase separation and allosteric regulation may be a generalizable phenomenon among enzymes associated with biomolecular condensates.
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10
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Wang J, Childers WS. The Future Potential of Biosensors to Investigate the Gut-Brain Axis. Front Bioeng Biotechnol 2022; 9:826479. [PMID: 35096802 PMCID: PMC8795891 DOI: 10.3389/fbioe.2021.826479] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Accepted: 12/28/2021] [Indexed: 11/13/2022] Open
Abstract
The multifaceted and heterogeneous nature of depression presents challenges in pinpointing treatments. Among these contributions are the interconnections between the gut microbiome and neurological function termed the gut-brain axis. A diverse range of microbiome-produced metabolites interact with host signaling and metabolic pathways through this gut-brain axis relationship. Therefore, biosensor detection of gut metabolites offers the potential to quantify the microbiome's contributions to depression. Herein we review synthetic biology strategies to detect signals that indicate gut-brain axis dysregulation that may contribute to depression. We also highlight future challenges in developing living diagnostics of microbiome conditions influencing depression.
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Affiliation(s)
| | - W. Seth Childers
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA, United States
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11
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Abstract
Microbially produced indole metabolites serve as a diverse family of interspecies and interkingdom signaling molecules in the context of human health, crop production, and antibiotic resistance. We mined the protein database for sensors of indole metabolites and developed a biosensor for indole-3-aldehyde (I3A). Microbially produced I3A has been associated with reducing inflammation in diseases such as ulcerative colitis by stimulating the aryl hydrocarbon receptor pathway. We engineered an E. coli strain embedded with a single plasmid carrying a chimeric two-component system that detects I3A. Our I3A receptor characterization confirmed binding site residues that contribute to the sensor's I3A detection range of 0.1-10 μM. This new I3A biosensor opens the door to sensing indole metabolites produced at various host-microbe interfaces and provides new parts for synthetic biology applications.
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Affiliation(s)
- Jiefei Wang
- Department of Chemistry, University of Pittsburgh, 219 Parkman Avenue, Pittsburgh, Pennsylvania 15260, United States
| | - Chao Zhang
- Department of Chemistry, University of Pittsburgh, 219 Parkman Avenue, Pittsburgh, Pennsylvania 15260, United States
| | - W. Seth Childers
- Department of Chemistry, University of Pittsburgh, 219 Parkman Avenue, Pittsburgh, Pennsylvania 15260, United States
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12
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Muthunayake NS, Tomares DT, Childers WS, Schrader JM. Phase-separated bacterial ribonucleoprotein bodies organize mRNA decay. Wiley Interdiscip Rev RNA 2020; 11:e1599. [PMID: 32445438 PMCID: PMC7554086 DOI: 10.1002/wrna.1599] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Revised: 04/16/2020] [Accepted: 04/17/2020] [Indexed: 01/12/2023]
Abstract
In bacteria, mRNA decay is controlled by megadalton scale macromolecular assemblies called, "RNA degradosomes," composed of nucleases and other RNA decay associated proteins. Recent advances in bacterial cell biology have shown that RNA degradosomes can assemble into phase-separated structures, termed bacterial ribonucleoprotein bodies (BR-bodies), with many analogous properties to eukaryotic processing bodies and stress granules. This review will highlight the functional role that BR-bodies play in the mRNA decay process through its organization into a membraneless organelle in the bacterial cytoplasm. This review will also highlight the phylogenetic distribution of BR-bodies across bacterial species, which suggests that these phase-separated structures are broadly distributed across bacteria, and in evolutionarily related mitochondria and chloroplasts. This article is categorized under: RNA Turnover and Surveillance > Turnover/Surveillance Mechanisms RNA Interactions with Proteins and Other Molecules > RNA-Protein Complexes RNA Export and Localization > RNA Localization RNA Turnover and Surveillance > Regulation of RNA Stability.
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Affiliation(s)
| | - Dylan T Tomares
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - W Seth Childers
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Jared M Schrader
- Department of Biological Sciences, Wayne State University, Detroit, Michigan, USA
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13
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Kowallis KA, Silfani EM, Kasumu AP, Rong G, So V, Childers WS. Synthetic Control of Signal Flow Within a Bacterial Multi-Kinase Network. ACS Synth Biol 2020; 9:1705-1713. [PMID: 32559383 DOI: 10.1021/acssynbio.0c00043] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The signal processing capabilities of bacterial signaling networks offer immense potential for advanced phospho-signaling systems for synthetic biology. Emerging models suggest that complex development may require interconnections between what were once thought to be isolated signaling arrays. For example, Caulobacter crescentus achieves the feat of asymmetric division by utilizing a novel pseudokinase DivL, which senses the output of one signaling pathway to modulate a second pathway. It has been proposed that DivL reverses signal flow by exploiting conserved kinase conformational changes and protein-protein interactions. We engineered a series of DivL-based modulators to synthetically stimulate reverse signaling of the network in vivo. Stimulation of conformational changes through the DivL signal transmission helix resulted in changes to hallmark features of the network: C. crescentus motility and DivL accumulation at the cell poles. Additionally, mutations to a conserved PAS sensor transmission motif disrupted reverse signaling flow in vivo. We propose that synthetic stimulation and sensor disruption provide strategies to define signaling circuit organization principles for the rational design and validation of synthetic pathways.
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Affiliation(s)
- Kimberly A. Kowallis
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - Elayna M. Silfani
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - Amanda P. Kasumu
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - Grace Rong
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - Victor So
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - W. Seth Childers
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
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14
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Abstract
Histidine kinases (HK) switch between conformational states that promote kinase and phosphatase activities to regulate diverse cellular processes. Past studies have shown that these functional states can display heterogeneity between cells in microbial communities and can vary at the subcellular level. Methods to track and correlate the kinase conformational state with the phenotypic response of living bacteria cells will offer new opportunities to interrogate bacterial signaling mechanisms. As a proof of principle, we incorporated both mClover3 (donor) and mRuby3 (acceptor) fluorescent proteins into the Caulobacter crescentus cell-cycle HK CckA as an in vivo fluorescence resonance energy transfer (FRET) sensor to detect these structural changes. Our engineered FRET sensor was responsive to CckA-specific input signals and detected subcellular changes in CckA signal integration that occurs as cells develop. We demonstrated the potential of using the CckA FRET sensor as an in vivo screening tool for HK inhibitors. In summary, we have developed a new HK FRET sensor design strategy that can be adopted to monitor in vivo changes for interrogation of a broad range of signaling mechanisms in living bacteria.
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Affiliation(s)
- Samuel W. Duvall
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - W. Seth Childers
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
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15
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Al-Husini N, Tomares DT, Pfaffenberger ZJ, Muthunayake NS, Samad MA, Zuo T, Bitar O, Aretakis JR, Bharmal MHM, Gega A, Biteen JS, Childers WS, Schrader JM. BR-Bodies Provide Selectively Permeable Condensates that Stimulate mRNA Decay and Prevent Release of Decay Intermediates. Mol Cell 2020; 78:670-682.e8. [PMID: 32343944 DOI: 10.1016/j.molcel.2020.04.001] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [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: 07/09/2019] [Revised: 12/16/2019] [Accepted: 03/30/2020] [Indexed: 12/22/2022]
Abstract
Biomolecular condensates play a key role in organizing RNAs and proteins into membraneless organelles. Bacterial RNP-bodies (BR-bodies) are a biomolecular condensate containing the RNA degradosome mRNA decay machinery, but the biochemical function of such organization remains poorly defined. Here, we define the RNA substrates of BR-bodies through enrichment of the bodies followed by RNA sequencing (RNA-seq). We find that long, poorly translated mRNAs, small RNAs, and antisense RNAs are the main substrates, while rRNA, tRNA, and other conserved non-coding RNAs (ncRNAs) are excluded from these bodies. BR-bodies stimulate the mRNA decay rate of enriched mRNAs, helping to reshape the cellular mRNA pool. We also observe that BR-body formation promotes complete mRNA decay, avoiding the buildup of toxic endo-cleaved mRNA decay intermediates. The combined selective permeability of BR-bodies for both enzymes and substrates together with the stimulation of the sub-steps of mRNA decay provide an effective organization strategy for bacterial mRNA decay.
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Affiliation(s)
- Nadra Al-Husini
- Department of Biological Sciences, Wayne State University, Detroit, MI 48202, USA
| | - Dylan T Tomares
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | | | | | - Mohammad A Samad
- Department of Biological Sciences, Wayne State University, Detroit, MI 48202, USA
| | - Tiancheng Zuo
- Department of Chemistry, University of Michigan, Ann Arbor, MI 48109, USA
| | - Obaidah Bitar
- Department of Biological Sciences, Wayne State University, Detroit, MI 48202, USA
| | - James R Aretakis
- Department of Biological Sciences, Wayne State University, Detroit, MI 48202, USA
| | | | - Alisa Gega
- Department of Biological Sciences, Wayne State University, Detroit, MI 48202, USA
| | - Julie S Biteen
- Department of Chemistry, University of Michigan, Ann Arbor, MI 48109, USA
| | - W Seth Childers
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA 15260, USA.
| | - Jared M Schrader
- Department of Biological Sciences, Wayne State University, Detroit, MI 48202, USA.
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16
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Abstract
Two-component systems allow bacteria to respond to changes in environmental or cytosolic conditions through autophosphorylation of a histidine kinase (HK) and subsequent transfer of the phosphate group to its downstream cognate response regulator (RR). The RR then elicits a cellular response, commonly through regulation of transcription. Engineering two-component system signaling networks provides a strategy to study bacterial signaling mechanisms related to bacterial cell survival, symbiosis, and virulence, and to develop sensory devices in synthetic biology. Here we focus on the principles for engineering the HK to identify unknown signal inputs, test signal transmission mechanisms, design small molecule sensors, and rewire two-component signaling networks.
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Affiliation(s)
| | - Samuel W Duvall
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA, USA
| | - Wei Zhao
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA, USA
| | - W Seth Childers
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA, USA. .,Chevron Science Center, University of Pittsburgh, Pittsburgh, PA, USA.
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17
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Al-Husini N, Tomares DT, Bitar O, Childers WS, Schrader JM. α-Proteobacterial RNA Degradosomes Assemble Liquid-Liquid Phase-Separated RNP Bodies. Mol Cell 2018; 71:1027-1039.e14. [PMID: 30197298 DOI: 10.1016/j.molcel.2018.08.003] [Citation(s) in RCA: 114] [Impact Index Per Article: 19.0] [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: 02/27/2018] [Revised: 06/11/2018] [Accepted: 07/31/2018] [Indexed: 12/30/2022]
Abstract
Ribonucleoprotein (RNP) granules play an important role in organizing eukaryotic mRNA metabolism via liquid-liquid phase separation (LLPS) of mRNA decay factors into membrane-less organelles in the cytoplasm. Here we show that the bacterium Caulobacter crescentus Ribonuclease (RNase) E assembles RNP LLPS condensates that we term bacterial RNP-bodies (BR-bodies), similar to eukaryotic P-bodies and stress granules. RNase E requires RNA to assemble a BR-body, and disassembly requires RNA cleavage, suggesting BR-bodies provide localized sites of RNA degradation. The unstructured C-terminal domain of RNase E is both necessary and sufficient to assemble the core of the BR-body, is functionally conserved in related α-proteobacteria, and influences mRNA degradation. BR-bodies are rapidly induced under cellular stresses and provide enhanced cell growth under stress. To our knowledge, Caulobacter RNase E is the first bacterial protein identified that forms LLPS condensates, providing an effective strategy for subcellular organization in cells lacking membrane-bound compartments.
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Affiliation(s)
- Nadra Al-Husini
- Department of Biological Sciences, Wayne State University, Detroit, MI, 48202, USA
| | - Dylan T Tomares
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA, 15260, USA
| | - Obaidah Bitar
- Department of Biological Sciences, Wayne State University, Detroit, MI, 48202, USA
| | - W Seth Childers
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA, 15260, USA.
| | - Jared M Schrader
- Department of Biological Sciences, Wayne State University, Detroit, MI, 48202, USA.
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18
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Omosun TO, Hsieh MC, Childers WS, Das D, Mehta AK, Anthony NR, Pan T, Grover MA, Berland KM, Lynn DG. Catalytic diversity in self-propagating peptide assemblies. Nat Chem 2017; 9:805-809. [DOI: 10.1038/nchem.2738] [Citation(s) in RCA: 128] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2015] [Accepted: 01/19/2017] [Indexed: 01/03/2023]
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19
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Mann TH, Seth Childers W, Blair JA, Eckart MR, Shapiro L. A cell cycle kinase with tandem sensory PAS domains integrates cell fate cues. Nat Commun 2016; 7:11454. [PMID: 27117914 PMCID: PMC4853435 DOI: 10.1038/ncomms11454] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2015] [Accepted: 03/22/2016] [Indexed: 11/11/2022] Open
Abstract
All cells must integrate sensory information to coordinate developmental events in space and time. The bacterium Caulobacter crescentus uses two-component phospho-signalling to regulate spatially distinct cell cycle events through the master regulator CtrA. Here, we report that CckA, the histidine kinase upstream of CtrA, employs a tandem-PAS domain sensor to integrate two distinct spatiotemporal signals. Using CckA reconstituted on liposomes, we show that one PAS domain modulates kinase activity in a CckA density-dependent manner, mimicking the stimulation of CckA kinase activity that occurs on its transition from diffuse to densely packed at the cell poles. The second PAS domain interacts with the asymmetrically partitioned second messenger cyclic-di-GMP, inhibiting kinase activity while stimulating phosphatase activity, consistent with the selective inactivation of CtrA in the incipient stalked cell compartment. The integration of these spatially and temporally regulated signalling events within a single signalling receptor enables robust orchestration of cell-type-specific gene regulation. The membrane-bound kinase CckA controls the activity of the Caulobacter crescentus master regulator CtrA, which in turn coordinates asymmetric cell division. Here, the authors show that CckA contains two sensory domains that have distinct sensitivities to fluctuations in cyclic-di-GMP concentration and subcellular niche.
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Affiliation(s)
- Thomas H Mann
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, California 94305, USA.,Department of Biochemistry, Stanford University School of Medicine, Stanford, California 94305, USA
| | - W Seth Childers
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, California 94305, USA
| | - Jimmy A Blair
- Department of Chemistry, Williams College, Williamstown, Massachusetts 01267, USA
| | - Michael R Eckart
- Stanford Protein and Nucleic Acid Facility, Beckman Center, Stanford University School of Medicine, Stanford, California 94305, USA
| | - Lucy Shapiro
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, California 94305, USA
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20
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Abstract
Bacteria face complex decisions when initiating developmental events such as sporulation, nodulation, virulence, and asymmetric cell division. These developmental decisions require global changes in genomic readout, and bacteria typically employ intricate (yet poorly understood) signaling networks that enable changes in cell function. The bacterium Caulobacter crescentus divides asymmetrically to yield two functionally distinct cells: a motile, chemotactic swarmer cell, and a sessile stalked cell with replication and division capabilities. Work from several Caulobacter labs has revealed that differentiation requires concerted regulation by several two-component system (TCS) signaling pathways that are differentially positioned at the poles of the predivisional cell (Figure 1). The strict unidirectional flow from histidine kinase (HK) to the response regulator (RR), observed in most studied TCS, is difficult to reconcile with the notion that information can be transmitted between two or more TCS signaling pathways. In this study, we uncovered a mechanism by which daughter cell fate, which is specified by the DivJ-DivK-PleC system and effectively encoded in the phosphorylation state of the single-domain RR DivK, is communicated to the CckA-ChpT-CtrA signaling pathway that regulates more than 100 genes for polar differentiation, replication initiation and cell division. Using structural biology and biochemical findings we proposed a mechanistic basis for TCS pathway coupling in which the DivL pseudokinase is repurposed as a sensor rather than participant in phosphotransduction.
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Affiliation(s)
- W S Childers
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, California, 94305
| | - Lucy Shapiro
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, California, 94305
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21
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Affiliation(s)
- Chen Liang
- Departments of Chemistry
and Biology, Emory University, Atlanta, Georgia 30322, United States
| | - Rong Ni
- Departments of Chemistry
and Biology, Emory University, Atlanta, Georgia 30322, United States
| | - Jillian E. Smith
- Departments of Chemistry
and Biology, Emory University, Atlanta, Georgia 30322, United States
| | - W. Seth Childers
- Departments of Chemistry
and Biology, Emory University, Atlanta, Georgia 30322, United States
| | - Anil K. Mehta
- Departments of Chemistry
and Biology, Emory University, Atlanta, Georgia 30322, United States
| | - David G. Lynn
- Departments of Chemistry
and Biology, Emory University, Atlanta, Georgia 30322, United States
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22
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Schrader JM, Zhou B, Li GW, Lasker K, Childers WS, Williams B, Long T, Crosson S, McAdams HH, Weissman JS, Shapiro L. The coding and noncoding architecture of the Caulobacter crescentus genome. PLoS Genet 2014; 10:e1004463. [PMID: 25078267 PMCID: PMC4117421 DOI: 10.1371/journal.pgen.1004463] [Citation(s) in RCA: 101] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2014] [Accepted: 05/13/2014] [Indexed: 11/24/2022] Open
Abstract
Caulobacter crescentus undergoes an asymmetric cell division controlled by a genetic circuit that cycles in space and time. We provide a universal strategy for defining the coding potential of bacterial genomes by applying ribosome profiling, RNA-seq, global 5′-RACE, and liquid chromatography coupled with tandem mass spectrometry (LC-MS) data to the 4-megabase C. crescentus genome. We mapped transcript units at single base-pair resolution using RNA-seq together with global 5′-RACE. Additionally, using ribosome profiling and LC-MS, we mapped translation start sites and coding regions with near complete coverage. We found most start codons lacked corresponding Shine-Dalgarno sites although ribosomes were observed to pause at internal Shine-Dalgarno sites within the coding DNA sequence (CDS). These data suggest a more prevalent use of the Shine-Dalgarno sequence for ribosome pausing rather than translation initiation in C. crescentus. Overall 19% of the transcribed and translated genomic elements were newly identified or significantly improved by this approach, providing a valuable genomic resource to elucidate the complete C. crescentus genetic circuitry that controls asymmetric cell division. Caulobacter crescentus is a model system for studying asymmetric cell division, a fundamental process that, through differential gene expression in the two daughter cells, enables the generation of cells with different fates. To explore how the genome directs and maintains asymmetry upon cell division, we performed a coordinated analysis of multiple genomic and proteomic datasets to identify the RNA and protein coding features in the C. crescentus genome. Our integrated analysis identifies many new genetic regulatory elements, adding significant regulatory complexity to the C. crescentus genome. Surprisingly, 75.4% of protein coding genes lack a canonical translation initiation sequence motif (the Shine-Dalgarno site) which hybridizes to the 3′ end of the ribosomal RNA allowing translation initiation. We find Shine-Dalgarno sites primarily inside of genes where they cause translating ribosomes to pause, possibly allowing nascent proteins to correctly fold. With our detailed map of genomic transcription and translation elements, a systems view of the genetic network that controls asymmetric cell division is within reach.
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Affiliation(s)
- Jared M. Schrader
- Department of Developmental Biology, Stanford University, Stanford, California, United States of America
| | - Bo Zhou
- Department of Developmental Biology, Stanford University, Stanford, California, United States of America
| | - Gene-Wei Li
- Department of Cellular and Molecular Pharmacology, California Institute of Quantitative Biology, Center for RNA Systems Biology, Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, California, United States of America
| | - Keren Lasker
- Department of Developmental Biology, Stanford University, Stanford, California, United States of America
| | - W. Seth Childers
- Department of Developmental Biology, Stanford University, Stanford, California, United States of America
| | - Brandon Williams
- Department of Developmental Biology, Stanford University, Stanford, California, United States of America
| | - Tao Long
- Department of Developmental Biology, Stanford University, Stanford, California, United States of America
| | - Sean Crosson
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, Illinois, United States of America
| | - Harley H. McAdams
- Department of Developmental Biology, Stanford University, Stanford, California, United States of America
| | - Jonathan S. Weissman
- Department of Cellular and Molecular Pharmacology, California Institute of Quantitative Biology, Center for RNA Systems Biology, Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, California, United States of America
| | - Lucy Shapiro
- Department of Developmental Biology, Stanford University, Stanford, California, United States of America
- * E-mail:
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23
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Li S, Sidorov AN, Mehta AK, Bisignano AJ, Das D, Childers WS, Schuler E, Jiang Z, Orlando TM, Berland K, Lynn DG. Neurofibrillar Tangle Surrogates: Histone H1 Binding to Patterned Phosphotyrosine Peptide Nanotubes. Biochemistry 2014; 53:4225-7. [DOI: 10.1021/bi500599a] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- Sha Li
- Departments
of Chemistry, Biology, and Physics, Emory University, Atlanta, Georgia 30322, United States
| | - Anton N. Sidorov
- School
of Chemistry and Biochemistry, ⊥School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Anil K. Mehta
- Departments
of Chemistry, Biology, and Physics, Emory University, Atlanta, Georgia 30322, United States
| | - Anthony J. Bisignano
- Departments
of Chemistry, Biology, and Physics, Emory University, Atlanta, Georgia 30322, United States
| | - Dibyendu Das
- Departments
of Chemistry, Biology, and Physics, Emory University, Atlanta, Georgia 30322, United States
| | - W. Seth Childers
- Departments
of Chemistry, Biology, and Physics, Emory University, Atlanta, Georgia 30322, United States
| | - Erin Schuler
- Departments
of Chemistry, Biology, and Physics, Emory University, Atlanta, Georgia 30322, United States
| | | | - Thomas M. Orlando
- School
of Chemistry and Biochemistry, ⊥School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Keith Berland
- Departments
of Chemistry, Biology, and Physics, Emory University, Atlanta, Georgia 30322, United States
| | - David G. Lynn
- Departments
of Chemistry, Biology, and Physics, Emory University, Atlanta, Georgia 30322, United States
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24
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Childers WS, Xu Q, Mathews II, Mann TH, Blair JA, Deacon AM, Shapiro L. Unique Signaling Logic within a Bacterial Cell Cycle Circuit. Biophys J 2014. [DOI: 10.1016/j.bpj.2013.11.1789] [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: 11/24/2022] Open
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25
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Mehta AK, Rosen RF, Childers WS, Gehman JD, Walker LC, Lynn DG. Context dependence of protein misfolding and structural strains in neurodegenerative diseases. Biopolymers 2013; 100:722-30. [PMID: 23893572 PMCID: PMC3979318 DOI: 10.1002/bip.22283] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [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: 03/24/2013] [Revised: 04/19/2013] [Accepted: 05/07/2013] [Indexed: 01/28/2023]
Abstract
Vast arrays of structural forms are accessible to simple amyloid peptides and environmental conditions can direct assembly into single phases. These insights are now being applied to the aggregation of the Aβ peptide of Alzheimer's disease and the identification of causative phases. We extend use of the imaging agent Pittsburgh compound B to discriminate among Aβ phases and begin to define conditions of relevance to the disease state. Also, we specifically highlight the development of methods for defining the structures of these more complex phases.
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Affiliation(s)
- Anil K. Mehta
- Departments of Chemistry and Biology, Alzheimer’s Disease Research Center, Emory University, Atlanta, Georgia 30322, USA
| | - Rebecca F. Rosen
- Yerkes National Primate Research Center, Center for Neurodegenerative Disease, Emory University, Atlanta, Georgia 30322, USA
| | - W. Seth Childers
- Departments of Chemistry and Biology, Alzheimer’s Disease Research Center, Emory University, Atlanta, Georgia 30322, USA
| | - John D. Gehman
- School of Chemistry, Bio21 Institute, University of Melbourne, Melbourne, Vic. 3010, Australia
| | - Lary C. Walker
- Yerkes National Primate Research Center, Center for Neurodegenerative Disease, Emory University, Atlanta, Georgia 30322, USA
- Department of Neurology, Emory University, Atlanta, Georgia 30322, USA
| | - David G. Lynn
- Departments of Chemistry and Biology, Alzheimer’s Disease Research Center, Emory University, Atlanta, Georgia 30322, USA
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26
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Blair JA, Xu Q, Childers WS, Mathews II, Kern JW, Eckart M, Deacon AM, Shapiro L. Branched signal wiring of an essential bacterial cell-cycle phosphotransfer protein. Structure 2013; 21:1590-601. [PMID: 23932593 DOI: 10.1016/j.str.2013.06.024] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2013] [Revised: 06/04/2013] [Accepted: 06/21/2013] [Indexed: 11/24/2022]
Abstract
Vital to bacterial survival is the faithful propagation of cellular signals, and in Caulobacter crescentus, ChpT is an essential mediator within the cell-cycle circuit. ChpT functions as a histidine-containing phosphotransfer protein (HPt) that shuttles a phosphoryl group from the receiver domain of CckA, the upstream hybrid histidine kinase (HK), to one of two downstream response regulators (CtrA or CpdR) that controls cell-cycle progression. To understand how ChpT interacts with multiple signaling partners, we solved the crystal structure of ChpT at 2.3 Å resolution. ChpT adopts a pseudo-HK architecture but does not bind ATP. We identified two point mutation classes affecting phosphotransfer and cell morphology: one that globally impairs ChpT phosphotransfer, and a second that mediates partner selection. Importantly, a small set of conserved ChpT residues promotes signaling crosstalk and contributes to the branched signaling that activates the master regulator CtrA while inactivating the CtrA degradation signal, CpdR.
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Affiliation(s)
- Jimmy A Blair
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
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27
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Affiliation(s)
- Rong Ni
- Center for Fundamental and Applied Molecular Evolution, NSF/NASA Center for Chemical Evolution, and Department of Chemistry, Emory University, Atlanta, GA 30322, USA
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28
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Ni R, Childers WS, Hardcastle KI, Mehta AK, Lynn DG. Remodeling Cross-β Nanotube Surfaces with Peptide/Lipid Chimeras. Angew Chem Int Ed Engl 2012. [DOI: 10.1002/ange.201201173] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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29
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Abstract
Recent evidence suggests that simple peptides can access diverse amphiphilic phases, and that these structures underlie the robust and widely distributed assemblies implicated in nearly 40 protein misfolding diseases. Here we exploit a minimal nucleating core of the Aβ peptide of Alzheimer's disease to map its morphologically accessible phases that include stable intermolecular molten particles, fibers, twisted and helical ribbons, and nanotubes. Analyses with both fluorescence lifetime imaging microscopy (FLIM) and transmission electron microscopy provide evidence for liquid-liquid phase separations, similar to the coexisting dilute and dense protein-rich liquid phases so critical for the liquid-solid transition in protein crystallization. We show that the observed particles are critical for transitions to the more ordered cross-β peptide phases, which are prevalent in all amyloid assemblies, and identify specific conditions that arrest assembly at the phase boundaries. We have identified a size dependence of the particles in order to transition to the para-crystalline phase and a width of the cross-β assemblies that defines the transition between twisted fibers and helically coiled ribbons. These experimental results reveal an interconnected network of increasing molecularly ordered cross-β transitions, greatly extending the initial computational models for cross-β assemblies.
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Affiliation(s)
- W Seth Childers
- Center for Fundamental and Applied Molecular Evolution, NSF/NASA Center for Chemical Evolution, Departments of Chemistry and Biology, Atlanta, Georgia 30322, USA
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30
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Abstract
Simple surfactants achieve remarkable long-range order in aqueous environments. This organizing potential is seen most dramatically in biological membranes where phospholipid assemblies both define cell boundaries and provide a ubiquitous structural scaffold for controlling cellular chemistry. Here we consider simple peptides that also spontaneously assemble into exceptionally ordered scaffolds, and review early data suggesting that these structures maintain the functional diversity of proteins. We argue that such scaffolds can achieve the required molecular order and catalytic agility for the emergence of chemical evolution.
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Affiliation(s)
- W Seth Childers
- Center for Fundamental and Applied Molecular Evolution and Center for Chemical Evolution, Department of Chemistry and Biology, Emory University, Atlanta, GA, United States
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31
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Affiliation(s)
- W. Seth Childers
- Center for Fundamental and Applied Molecular Evolution (FAME), and Department of Chemistry and Biology, Emory University, Atlanta, Georgia 30322
| | - Anil K. Mehta
- Center for Fundamental and Applied Molecular Evolution (FAME), and Department of Chemistry and Biology, Emory University, Atlanta, Georgia 30322
| | - Kun Lu
- Center for Fundamental and Applied Molecular Evolution (FAME), and Department of Chemistry and Biology, Emory University, Atlanta, Georgia 30322
| | - David G. Lynn
- Center for Fundamental and Applied Molecular Evolution (FAME), and Department of Chemistry and Biology, Emory University, Atlanta, Georgia 30322
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32
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Liu P, Ni R, Mehta AK, Childers WS, Lakdawala A, Pingali SV, Thiyagarajan P, Lynn DG. Nucleobase-Directed Amyloid Nanotube Assembly. J Am Chem Soc 2009. [DOI: 10.1021/ja9021667] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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33
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Liu P, Ni R, Mehta AK, Childers WS, Lakdawala A, Pingali SV, Thiyagarajan P, Lynn DG. Nucleobase-directed amyloid nanotube assembly. J Am Chem Soc 2009; 130:16867-9. [PMID: 19053426 DOI: 10.1021/ja807425h] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Cytosine nucleobases were successfully incorporated into the side chain of the self-assembling amyloid peptide fragment HHQALVFFA to give ccAQLVFFA. At a pH range of 3-4, where cytosine is expected to be partially protonated, small-angle X-ray scattering analyses revealed the nucleobase peptide assembles to be well-defined nanotubes with an outer diameter of 24.8 nm and wall thicknesses of 3.3 nm. FT-IR and X-ray diffraction confirmed beta-sheet-rich assembly with the characteristic cross-beta architecture of amyloid. The beta-sheet registry, determined by measuring (13)CO-(13)CO backbone distances with solid-state NMR and linear dichroism, placed the cytosine bases roughly perpendicular to the nanotube axis, resulting in a model where the complementary interactions between the cytosine bases increases beta-sheet stacking to give the nanotube architecture. These scaffolds then extend the templates used to encode biological information beyond the nucleic acid duplexes and into covalent networks whose self-assembly is still defined by a precise complementarity of the side-chain registry.
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Affiliation(s)
- Peng Liu
- Center for Fundamental and Applied Molecular Evolution, Department of Chemistry, Emory University, Atlanta, Georgia 30322, USA
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Mehta AK, Lu K, Childers WS, Liang Y, Dublin SN, Dong J, Snyder JP, Pingali SV, Thiyagarajan P, Lynn DG. Facial symmetry in protein self-assembly. J Am Chem Soc 2008; 130:9829-35. [PMID: 18593163 DOI: 10.1021/ja801511n] [Citation(s) in RCA: 198] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Amyloids are self-assembled protein architectures implicated in dozens of misfolding diseases. These assemblies appear to emerge through a "selection" of specific conformational "strains" which nucleate and propagate within cells to cause disease. The short Abeta(16-22) peptide, which includes the central core of the Alzheimer's disease Abeta peptide, generates an amyloid fiber which is morphologically indistinguishable from the full-length peptide fiber, but it can also form other morphologies under distinct conditions. Here we combine spectroscopic and microscopy analyses that reveal the subtle atomic-level differences that dictate assembly of two conformationally pure Abeta(16-22) assemblies, amyloid fibers and nanotubes, and define the minimal repeating unit for each assembly.
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Affiliation(s)
- Anil K Mehta
- Center for the Analysis of Supramolecular Self-assemblies, Department of Chemistry, Emory University, Atlanta, Georgia 30322, USA
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Dong J, Canfield JM, Mehta AK, Shokes JE, Tian B, Childers WS, Simmons JA, Mao Z, Scott RA, Warncke K, Lynn DG. Engineering metal ion coordination to regulate amyloid fibril assembly and toxicity. Proc Natl Acad Sci U S A 2007; 104:13313-8. [PMID: 17686982 PMCID: PMC1948904 DOI: 10.1073/pnas.0702669104] [Citation(s) in RCA: 110] [Impact Index Per Article: 6.5] [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] [Indexed: 11/18/2022] Open
Abstract
Protein and peptide assembly into amyloid has been implicated in functions that range from beneficial epigenetic controls to pathological etiologies. However, the exact structures of the assemblies that regulate biological activity remain poorly defined. We have previously used Zn(2+) to modulate the assembly kinetics and morphology of congeners of the amyloid beta peptide (Abeta) associated with Alzheimer's disease. We now reveal a correlation among Abeta-Cu(2+) coordination, peptide self-assembly, and neuronal viability. By using the central segment of Abeta, HHQKLVFFA or Abeta(13-21), which contains residues H13 and H14 implicated in Abeta-metal ion binding, we show that Cu(2+) forms complexes with Abeta(13-21) and its K16A mutant and that the complexes, which do not self-assemble into fibrils, have structures similar to those found for the human prion protein, PrP. N-terminal acetylation and H14A substitution, Ac-Abeta(13-21)H14A, alters metal coordination, allowing Cu(2+) to accelerate assembly into neurotoxic fibrils. These results establish that the N-terminal region of Abeta can access different metal-ion-coordination environments and that different complexes can lead to profound changes in Abeta self-assembly kinetics, morphology, and toxicity. Related metal-ion coordination may be critical to the etiology of other neurodegenerative diseases.
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Affiliation(s)
- Jijun Dong
- *Departments of Chemistry and Biology, Center for the Analysis of Supramolecular Self-Assemblies, and
| | | | - Anil K. Mehta
- *Departments of Chemistry and Biology, Center for the Analysis of Supramolecular Self-Assemblies, and
| | - Jacob E. Shokes
- Department of Chemistry and Center for Metalloenzyme Studies, University of Georgia, Athens, GA 30602; and
| | - Bo Tian
- Departments of Pharmacology and Neurology, Emory University School of Medicine, Atlanta, GA 30322
| | - W. Seth Childers
- *Departments of Chemistry and Biology, Center for the Analysis of Supramolecular Self-Assemblies, and
| | - James A. Simmons
- *Departments of Chemistry and Biology, Center for the Analysis of Supramolecular Self-Assemblies, and
| | - Zixu Mao
- Departments of Pharmacology and Neurology, Emory University School of Medicine, Atlanta, GA 30322
| | - Robert A. Scott
- Department of Chemistry and Center for Metalloenzyme Studies, University of Georgia, Athens, GA 30602; and
| | - Kurt Warncke
- *Departments of Chemistry and Biology, Center for the Analysis of Supramolecular Self-Assemblies, and
- Department of Physics, Emory University, Atlanta, GA 30322
| | - David G. Lynn
- *Departments of Chemistry and Biology, Center for the Analysis of Supramolecular Self-Assemblies, and
- To whom correspondence should be addressed. E-mail:
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Lu K, Guo L, Mehta AK, Childers WS, Dublin SN, Skanthakumar S, Conticello VP, Thiyagarajan P, Apkarian RP, Lynn DG. Macroscale assembly of peptide nanotubes. Chem Commun (Camb) 2007:2729-31. [PMID: 17594035 DOI: 10.1039/b701029j] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Simple oligopeptides that self-assemble into homogeneous nanotubes can be directed to further assemble into macroscale parallel arrays through protein "salting out" strategies.
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Affiliation(s)
- Kun Lu
- Center for the Analysis of Supramolecular Self-assemblies, Departments of Chemistry and Biology, Emory University, Atlanta, Georgia 30322, USA
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Abstract
Stimulation of synaptoneurosome suspensions by the neurotransmitter glutamate gives rise to rapid loading of ribosomes onto mRNA and increased incorporation of amino acids into trichloroacetic acid-precipitable polypeptides. Metabotropic glutamate receptors (mGluRs) are responsible for this effect. Although simultaneous Ca2+ entry and mGluR stimulation do not change the response, entry of Ca2+ 30 s or 3 min before mGluR stimulation markedly depresses the polyribosomal loading. Either NMDA or ionophore (A23187) produces the depression. A calmodulin antagonist, W7, alleviates the effect, suggesting that inactivation of phospholipase A2 by calcium-calmodulin-dependent kinase II is partially responsible for the phenomenon. Thus, interaction between different classes of glutamate receptors affects the control of protein translation at the synapse. This effect may partially explain recent observations of negative interactions between receptor classes in induction of long-term potentiation.
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Affiliation(s)
- I J Weiler
- Department of Psychology, Beckman Institute, University of Illinois at Urbana-Champaign
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