Ammon Posey
Research Scientist, Washington University in St. Louis
Research Interests
About
Publications
A Lethal de Novo Mutation in the Middle Domain of the Dynamin-related GTPase Drp1 Impairs Higher Order Assembly and Mitochondrial Division
Journal of Biological Chemistry / Oct 01, 2010
Chang, C.-R., Manlandro, C. M., Arnoult, D., Stadler, J., Posey, A. E., Hill, R. B., & Blackstone, C. (2010). A Lethal de Novo Mutation in the Middle Domain of the Dynamin-related GTPase Drp1 Impairs Higher Order Assembly and Mitochondrial Division. Journal of Biological Chemistry, 285(42), 32494–32503. https://doi.org/10.1074/jbc.m110.142430
Phase Separation of Intrinsically Disordered Proteins
Methods in Enzymology / Jan 01, 2018
Posey, A. E., Holehouse, A. S., & Pappu, R. V. (2018). Phase Separation of Intrinsically Disordered Proteins. Intrinsically Disordered Proteins, 1–30. https://doi.org/10.1016/bs.mie.2018.09.035
Arginine-Enriched Mixed-Charge Domains Provide Cohesion for Nuclear Speckle Condensation
Molecular Cell / Mar 01, 2020
Greig, J. A., Nguyen, T. A., Lee, M., Holehouse, A. S., Posey, A. E., Pappu, R. V., & Jedd, G. (2020). Arginine-Enriched Mixed-Charge Domains Provide Cohesion for Nuclear Speckle Condensation. Molecular Cell, 77(6), 1237-1250.e4. https://doi.org/10.1016/j.molcel.2020.01.025
Profilin reduces aggregation and phase separation of huntingtin N-terminal fragments by preferentially binding to soluble monomers and oligomers
Journal of Biological Chemistry / Mar 01, 2018
Posey, A. E., Ruff, K. M., Harmon, T. S., Crick, S. L., Li, A., Diamond, M. I., & Pappu, R. V. (2018). Profilin reduces aggregation and phase separation of huntingtin N-terminal fragments by preferentially binding to soluble monomers and oligomers. Journal of Biological Chemistry, 293(10), 3734–3746. https://doi.org/10.1074/jbc.ra117.000357
Self-Assembly of Block Heterochiral Peptides into Helical Tapes
Journal of the American Chemical Society / Apr 27, 2020
Clover, T. M., O’Neill, C. L., Appavu, R., Lokhande, G., Gaharwar, A. K., Posey, A. E., White, M. A., & Rudra, J. S. (2020). Self-Assembly of Block Heterochiral Peptides into Helical Tapes. Journal of the American Chemical Society, 142(47), 19809–19813. https://doi.org/10.1021/jacs.9b09755
Inhibition of amyloid beta fibril formation by monomeric human transthyretin
Protein Science / Mar 14, 2018
Garai, K., Posey, A. E., Li, X., Buxbaum, J. N., & Pappu, R. V. (2018). Inhibition of amyloid beta fibril formation by monomeric human transthyretin. Protein Science, 27(7), 1252–1261. Portico. https://doi.org/10.1002/pro.3396
Molecular Motor Dnm1 Synergistically Induces Membrane Curvature To Facilitate Mitochondrial Fission
ACS Central Science / Nov 08, 2017
Lee, M. W., Lee, E. Y., Lai, G. H., Kennedy, N. W., Posey, A. E., Xian, W., Ferguson, A. L., Hill, R. B., & Wong, G. C. L. (2017). Molecular Motor Dnm1 Synergistically Induces Membrane Curvature To Facilitate Mitochondrial Fission. ACS Central Science, 3(11), 1156–1167. https://doi.org/10.1021/acscentsci.7b00338
GADIS: Algorithm for designing sequences to achieve target secondary structure profiles of intrinsically disordered proteins
Protein Engineering Design and Selection / Aug 08, 2016
Harmon, T. S., Crabtree, M. D., Shammas, S. L., Posey, A. E., Clarke, J., & Pappu, R. V. (2016). GADIS: Algorithm for designing sequences to achieve target secondary structure profiles of intrinsically disordered proteins. Protein Engineering Design and Selection, 29(9), 339–346. https://doi.org/10.1093/protein/gzw034
Dilute phase oligomerization can oppose phase separation and modulate material properties of a ribonucleoprotein condensate
Apr 20, 2021
Seim, I., Posey, A. E., Snead, W. T., Stormo, B. M., Klotsa, D., Pappu, R. V., & Gladfelter, A. S. (2021). Dilute phase oligomerization can oppose phase separation and modulate material properties of a ribonucleoprotein condensate. https://doi.org/10.1101/2021.04.19.440511
A Targeted Mutation Identified through pK Measurements Indicates a Postrecruitment Role for Fis1 in Yeast Mitochondrial Fission
Journal of Biological Chemistry / Sep 01, 2016
Koppenol-Raab, M., Harwig, M. C., Posey, A. E., Egner, J. M., MacKenzie, K. R., & Hill, R. B. (2016). A Targeted Mutation Identified through pK Measurements Indicates a Postrecruitment Role for Fis1 in Yeast Mitochondrial Fission. Journal of Biological Chemistry, 291(39), 20329–20344. https://doi.org/10.1074/jbc.m116.724005
Gold Nanoshell Assembly on a Ferritin Protein Employed as a Bio-Template
Journal of Nanoscience and Nanotechnology / Mar 01, 2010
Kim, J.-W., Posey, AmmonE., Watt, GeraldD., Choi, SangH., & Lillehei, PeterT. (2010). Gold Nanoshell Assembly on a Ferritin Protein Employed as a Bio-Template. Journal of Nanoscience and Nanotechnology, 10(3), 1771–1777. https://doi.org/10.1166/jnn.2010.2078
Mechanistic Inferences From Analysis of Measurements of Protein Phase Transitions in Live Cells
Journal of Molecular Biology / Jun 01, 2021
Posey, A. E., Ruff, K. M., Lalmansingh, J. M., Kandola, T. S., Lange, J. J., Halfmann, R., & Pappu, R. V. (2021). Mechanistic Inferences From Analysis of Measurements of Protein Phase Transitions in Live Cells. Journal of Molecular Biology, 433(12), 166848. https://doi.org/10.1016/j.jmb.2021.166848
A First Glimpse of Nucleation of Phase Transitions in Living Cells
Molecular Cell / Jul 01, 2018
Posey, A. E., & Pappu, R. V. (2018). A First Glimpse of Nucleation of Phase Transitions in Living Cells. Molecular Cell, 71(1), 1–3. https://doi.org/10.1016/j.molcel.2018.06.028
Basin Mapping Method for Extracting Comparative Assessments of Protein Phase Behavior from In Vivo Measurements
Biophysical Journal / Feb 01, 2020
Lalmansingh, J. M., Posey, A. E., Kandola, T., Halfmann, R., & Pappu, R. V. (2020). Basin Mapping Method for Extracting Comparative Assessments of Protein Phase Behavior from In Vivo Measurements. Biophysical Journal, 118(3), 538a. https://doi.org/10.1016/j.bpj.2019.11.2949
Increasing the Accuracy in All-Atom Simulations of Intrinsically Disordered Proteins based on the Absinth Model
Biophysical Journal / Feb 01, 2018
Fossat, M. J., Harmon, T. S., Posey, A. E., Choi, J.-M., & Pappu, R. V. (2018). Increasing the Accuracy in All-Atom Simulations of Intrinsically Disordered Proteins based on the Absinth Model. Biophysical Journal, 114(3), 432a. https://doi.org/10.1016/j.bpj.2017.11.2392
The Variable Domain from the Mitochondrial Fission Mechanoenzyme Drp1 Promotes Liquid-Liquid Phase Separation
Biophysical Journal / Feb 01, 2020
Hill, B., Posey, A. E., Bagheri, M., Harwig, M. C., Kennedy, N. W., Hilser, V. J., & Harden, J. L. (2020). The Variable Domain from the Mitochondrial Fission Mechanoenzyme Drp1 Promotes Liquid-Liquid Phase Separation. Biophysical Journal, 118(3), 193a. https://doi.org/10.1016/j.bpj.2019.11.1170
Quantitative analysis of intracellular protein phase transitions
Biophysical Journal / Feb 01, 2023
Posey, A. E., & Pappu, R. V. (2023). Quantitative analysis of intracellular protein phase transitions. Biophysical Journal, 122(3), 206a. https://doi.org/10.1016/j.bpj.2022.11.1239
How does sequence influence charge regulation of disordered proteins?
Biophysical Journal / Feb 01, 2023
Fossat, M. J., Posey, A. E., Gupta, N., & Pappu, R. V. (2023). How does sequence influence charge regulation of disordered proteins? Biophysical Journal, 122(3), 200a. https://doi.org/10.1016/j.bpj.2022.11.1211
Demixing of distinct ribonucleoprotein condensates is under dynamical control
Biophysical Journal / Feb 01, 2023
Pappu, R. V., Lin, A. Z., Ruff, K. M., Jalihal, A. P., Dar, F., Posey, A. E., King, M. R., Lalmansingh, J. M., & Gladfelter, A. S. (2023). Demixing of distinct ribonucleoprotein condensates is under dynamical control. Biophysical Journal, 122(3), 443a. https://doi.org/10.1016/j.bpj.2022.11.2390
Dynamical control enables the formation of demixed biomolecular condensates
Feb 08, 2023
Pappu, R., Lin, A., Ruff, K., Jalihal, A., Dar, F., King, M., Lalmansingh, J., Posey, A., Seim, I., & Gladfelter, A. (2023). Dynamical control enables the formation of demixed biomolecular condensates. https://doi.org/10.21203/rs.3.rs-2440278/v1
Dynamical control enables the formation of demixed biomolecular condensates
Feb 08, 2023
Pappu, R., Lin, A., Ruff, K., Jalihal, A., Dar, F., King, M., Lalmansingh, J., Posey, A., Seim, I., & Gladfelter, A. (2023). Dynamical control enables the formation of demixed biomolecular condensates. https://doi.org/10.21203/rs.3.rs-2440278/v1
Quantifying Coexistence Concentrations in Multi-Component Phase-Separating Systems Using Analytical HPLC
Biomolecules / Oct 14, 2022
Bremer, A., Posey, A. E., Borgia, M. B., Borcherds, W. M., Farag, M., Pappu, R. V., & Mittag, T. (2022). Quantifying Coexistence Concentrations in Multi-Component Phase-Separating Systems Using Analytical HPLC. Biomolecules, 12(10), 1480. https://doi.org/10.3390/biom12101480
Heterogeneous distributions of charge states determine the apparent net charge of intrinsically disordered proteins
Biophysical Journal / Feb 01, 2022
Posey, A. E., Fossat, M. J., & Pappu, R. V. (2022). Heterogeneous distributions of charge states determine the apparent net charge of intrinsically disordered proteins. Biophysical Journal, 121(3), 197a. https://doi.org/10.1016/j.bpj.2021.11.1732
The variable domain from the mitochondrial fission mechanoenzyme Drp1 promotes liquid-liquid phase separation
Biophysical Journal / Feb 01, 2022
Hill, B., Posey, A. E., BAGHERI, M., Harwig, M. C., Kennedy, N. W., Hilser, V. J., & Harden, J. L. (2022). The variable domain from the mitochondrial fission mechanoenzyme Drp1 promotes liquid-liquid phase separation. Biophysical Journal, 121(3), 40a. https://doi.org/10.1016/j.bpj.2021.11.2507
Charge state heterogeneity in single alpha helices helps maintain helicity over a large range of pH values
Biophysical Journal / Feb 01, 2022
Fossat, M. J., Posey, A. E., & Pappu, R. V. (2022). Charge state heterogeneity in single alpha helices helps maintain helicity over a large range of pH values. Biophysical Journal, 121(3), 300a. https://doi.org/10.1016/j.bpj.2021.11.1254
The soluble N-termini of mechanosensitive ion channels MSL8, MSL9, and MSL10 are environmentally sensitive intrinsically disordered regions with distinct biophysical characteristics
Oct 14, 2022
Flynn, A. J., Miller, K., Codjoe, J. M., King, M. R., Posey, A. E., & Haswell, E. S. (2022). The soluble N-termini of mechanosensitive ion channels MSL8, MSL9, and MSL10 are environmentally sensitive intrinsically disordered regions with distinct biophysical characteristics. https://doi.org/10.1101/2022.10.14.512244
Uncovering the Physical Basis for Selective Mixing Versus Unmixing of Protein-RNA Condensates
Biophysical Journal / Feb 01, 2021
Lin, A. Z., Posey, A. E., Dar, F., Gladfelter, A. S., & Pappu, R. V. (2021). Uncovering the Physical Basis for Selective Mixing Versus Unmixing of Protein-RNA Condensates. Biophysical Journal, 120(3), 93a. https://doi.org/10.1016/j.bpj.2020.11.774
Phase Separation of the Variable Domain of Dynamin Related Protein 1 in TMAO Suggests a Role in Assembly
Biophysical Journal / Feb 01, 2018
Hill, B., Posey, A., Bagheri, M., Kennedy, N., & Harden, J. (2018). Phase Separation of the Variable Domain of Dynamin Related Protein 1 in TMAO Suggests a Role in Assembly. Biophysical Journal, 114(3), 589a. https://doi.org/10.1016/j.bpj.2017.11.3223
Heuristics for the Effects of Sequence and Conformational Contexts on pKA Values of Ionizable Residues Inferred from Q-Canonical Monte Carlo Simulations
Biophysical Journal / Feb 01, 2020
Fossat, M. J., Posey, A. E., & Pappu, R. V. (2020). Heuristics for the Effects of Sequence and Conformational Contexts on pKA Values of Ionizable Residues Inferred from Q-Canonical Monte Carlo Simulations. Biophysical Journal, 118(3), 539a–540a. https://doi.org/10.1016/j.bpj.2019.11.2956
Principles of Ligand Modulation of Phase Behavior in Multicomponent Systems
Biophysical Journal / Feb 01, 2020
Ruff, K. M., Dar, F., Posey, A. E., & Pappu, R. V. (2020). Principles of Ligand Modulation of Phase Behavior in Multicomponent Systems. Biophysical Journal, 118(3), 371a. https://doi.org/10.1016/j.bpj.2019.11.2126
Quantifying the Effects of Charge Regulation on Disorder-Order Transitions of Highly Charged Protein Sequences
Biophysical Journal / Feb 01, 2020
Posey, A. E., Fossat, M. J., & Pappu, R. V. (2020). Quantifying the Effects of Charge Regulation on Disorder-Order Transitions of Highly Charged Protein Sequences. Biophysical Journal, 118(3), 540a–541a. https://doi.org/10.1016/j.bpj.2019.11.2960
Introducing a Novel Multi-Level Method for Simulating the pH Dependence of Charge State Fluctuations and Conformational Ensembles of Intrinsically Disordered Proteins
Biophysical Journal / Feb 01, 2019
Fossat, M. J., Posey, A. E., & Pappu, R. V. (2019). Introducing a Novel Multi-Level Method for Simulating the pH Dependence of Charge State Fluctuations and Conformational Ensembles of Intrinsically Disordered Proteins. Biophysical Journal, 116(3), 287a. https://doi.org/10.1016/j.bpj.2018.11.1549
Modeling the Effects of Ligand Binding on the Phase Behavior of Aggregation-Prone Proteins
Biophysical Journal / Feb 01, 2019
Ruff, K. M., Posey, A. E., & Pappu, R. V. (2019). Modeling the Effects of Ligand Binding on the Phase Behavior of Aggregation-Prone Proteins. Biophysical Journal, 116(3), 199a. https://doi.org/10.1016/j.bpj.2018.11.1100
Experimental and Theoretical Methods for Mapping Coexistence Curves of Phase-Separating Biological Macromolecules
Biophysical Journal / Feb 01, 2019
Posey, A. E., Holehouse, A. S., Ruff, K. M., & Pappu, R. V. (2019). Experimental and Theoretical Methods for Mapping Coexistence Curves of Phase-Separating Biological Macromolecules. Biophysical Journal, 116(3), 349a. https://doi.org/10.1016/j.bpj.2018.11.1901
Advances in Quantitative Analysis of Intracellular Protein Phase Separation Kinetics and its Modulation by Cellular Interactions
Biophysical Journal / Feb 01, 2018
Posey, A. E., Kandola, T., Pappu, R. V., & Halfmann, R. (2018). Advances in Quantitative Analysis of Intracellular Protein Phase Separation Kinetics and its Modulation by Cellular Interactions. Biophysical Journal, 114(3), 588a. https://doi.org/10.1016/j.bpj.2017.11.3219
Sequence-Encoded Charge Patterning of the Intrinsically Disordered Tail of FtsZ Impacts Polymerization and Bacterial Cell Division
Biophysical Journal / Feb 01, 2018
Cohan, M., Posey, A., Mittal, A., Grigsby, S., Holehouse, A., Buske, P. J., Levin, P. A., & Pappu, R. V. (2018). Sequence-Encoded Charge Patterning of the Intrinsically Disordered Tail of FtsZ Impacts Polymerization and Bacterial Cell Division. Biophysical Journal, 114(3), 590a. https://doi.org/10.1016/j.bpj.2017.11.3226
The Intrinsically Disordered Tail of FtsZ Impacts Polymerization and Bacterial Cell Division Through Sequence-Encoded Charge Patterning
Biophysical Journal / Feb 01, 2017
Cohan, M. C., Posey, A., Grigsby, S., Holehouse, A. S., Mittal, A., Buske, P. J., Levin, P., & Pappu, R. V. (2017). The Intrinsically Disordered Tail of FtsZ Impacts Polymerization and Bacterial Cell Division Through Sequence-Encoded Charge Patterning. Biophysical Journal, 112(3), 510a–511a. https://doi.org/10.1016/j.bpj.2016.11.2760
Polyglutamine Length Dependent Structural Properties and Phase Behavior of Huntingtin Exon 1
Biophysical Journal / Feb 01, 2017
Ruff, K. M., Warner, J. B., Posey, A. E., Siong Tan, P., Lemke, E. A., Pappu, R. V., & Lashuel, H. A. (2017). Polyglutamine Length Dependent Structural Properties and Phase Behavior of Huntingtin Exon 1. Biophysical Journal, 112(3), 511a. https://doi.org/10.1016/j.bpj.2016.11.2762
Charge Neutralization, Not Salt Bridges, Stabilizes Alpha Helices in Repeating Blocks of Acidic and Basic Residues
Biophysical Journal / Feb 01, 2017
Posey, A. E., Harmon, T. S., & Pappu, R. V. (2017). Charge Neutralization, Not Salt Bridges, Stabilizes Alpha Helices in Repeating Blocks of Acidic and Basic Residues. Biophysical Journal, 112(3), 345a–346a. https://doi.org/10.1016/j.bpj.2016.11.1874
Profilin Binding Modulates the Aggregation and Phase Separation of Huntingtin N-Terminal Fragments via Polyphasic Linkage
Biophysical Journal / Feb 01, 2016
Posey, A. E., Ruff, K. M., Harmon, T. S., Holehouse, A. S., & Pappu, R. V. (2016). Profilin Binding Modulates the Aggregation and Phase Separation of Huntingtin N-Terminal Fragments via Polyphasic Linkage. Biophysical Journal, 110(3), 399a. https://doi.org/10.1016/j.bpj.2015.11.2156
Molecular Mechanisms Behind Mitochondrial Fission
Biophysical Journal / Jan 01, 2012
Hill, B., Koppenol-Raab, M., Lees, J. P. B., Marie Manlandro, C., Picton, L. K., Posey, A., & Wells, R. C. (2012). Molecular Mechanisms Behind Mitochondrial Fission. Biophysical Journal, 102(3), 26a. https://doi.org/10.1016/j.bpj.2011.11.167
Dynamical control enables the formation of demixed biomolecular condensates
Jan 04, 2023
Lin, A. Z., Ruff, K. M., Jalihal, A., Dar, F., King, M. R., Lalmansingh, J. M., Posey, A. E., Seim, I., Gladfelter, A. S., & Pappu, R. V. (2023). Dynamical control enables the formation of demixed biomolecular condensates. https://doi.org/10.1101/2023.01.04.522702
Uncovering the Contributions of Charge Regulation to the Stability of Single Alpha Helices**
ChemPhysChem / Jan 04, 2023
Fossat, M. J., Posey, A. E., & Pappu, R. V. (2023). Uncovering the Contributions of Charge Regulation to the Stability of Single Alpha Helices**. ChemPhysChem. Portico. https://doi.org/10.1002/cphc.202200746
Uncovering the contributions of charge regulation to the stability of single alpha helices
Sep 28, 2022
Fossat, M. J., Posey, A. E., & Pappu, R. V. (2022). Uncovering the contributions of charge regulation to the stability of single alpha helices. https://doi.org/10.1101/2022.09.28.509894
Quantifying charge state heterogeneity for proteins with multiple ionizable residues
Biophysical Journal / Dec 01, 2021
Fossat, M. J., Posey, A. E., & Pappu, R. V. (2021). Quantifying charge state heterogeneity for proteins with multiple ionizable residues. Biophysical Journal, 120(24), 5438–5453. https://doi.org/10.1016/j.bpj.2021.11.2886
Glycine-Rich Peptides from FUS Have an Intrinsic Ability to Self-Assemble into Fibers and Networked Fibrils
Biochemistry / Oct 14, 2021
Kar, M., Posey, A. E., Dar, F., Hyman, A. A., & Pappu, R. V. (2021). Glycine-Rich Peptides from FUS Have an Intrinsic Ability to Self-Assemble into Fibers and Networked Fibrils. Biochemistry, 60(43), 3213–3222. https://doi.org/10.1021/acs.biochem.1c00501
Quantifying charge state heterogeneity for proteins with multiple ionizable residues
Sep 01, 2021
Fossat, M. J., Posey, A. E., & Pappu, R. V. (2021). Quantifying charge state heterogeneity for proteins with multiple ionizable residues. https://doi.org/10.1101/2021.08.31.458420
Mechanistic inferences from analysis of measurements of protein phase transitions in live cells
Nov 05, 2020
Posey, A. E., Ruff, K. M., Lalmansingh, J. M., Kandola, T. S., Lange, J. J., Halfmann, R., & Pappu, R. V. (2020). Mechanistic inferences from analysis of measurements of protein phase transitions in live cells. https://doi.org/10.1101/2020.11.04.369017
Evolved sequence features within the intrinsically disordered tail influence FtsZ assembly and bacterial cell division
Apr 14, 2018
Cohan, M. C., Posey, A. E., Grigsby, S. J., Mittal, A., Holehouse, A. S., Buske, P. J., Levin, P. A., & Pappu, R. V. (2018). Evolved sequence features within the intrinsically disordered tail influence FtsZ assembly and bacterial cell division. https://doi.org/10.1101/301622
Education
Johns Hopkins University
PhD, Molecular Biophysics / 2014
Brigham Young University
BS, Biophysics / 2006
Experience
Washington University in St. Louis
Senior Research Scientist / 2014 — Present
Johns Hopkins University
Doctoral Researcher / 2008 — 2014
Dissertation: Intrinsic disorder and amphitropism in the mitochondrial fission mechanoenzyme Drp1
NASA Langley Research Center
Research Scholar / 2004 — 2005
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