Interdomain salt-bridges in the Ebola virus protein VP40 and their role in domain association and plasma membrane localization.
The Ebola virus protein VP40 is a transformer protein that possesses an extraordinary ability to accomplish multiple functions by transforming into various oligomeric conformations. The disengagement of the C-terminal domain (CTD) from the N-terminal domain (NTD) is a crucial step in the conformational transformations of VP40 from the dimeric form to the hexameric form or octameric ring structure. Here, we use various molecular dynamics (MD) simulations to investigate the dynamics of the VP40 protein and the roles of interdomain interactions that are important for the domain-domain association and dissociation, and report on experimental results of the behavior of mutant variants of VP40. The MD studies find that various salt-bridge interactions modulate the VP40 domain dynamics by providing conformational specificity through interdomain interactions. The MD simulations reveal a novel salt-bridge between D45-K326 when the CTD participates in a latch-like interaction with the NTD. The D45-K326 salt-bridge interaction is proposed to help domain-domain association, whereas the E76-K291 interaction is important for stabilizing the closed-form structure. The effects of the removal of important VP40 salt-bridges on plasma membrane (PM) localization, VP40 oligomerization, and virus like particle (VLP) budding assays were investigated experimentally by live cell imaging using an EGFP-tagged VP40 system. It is found that the mutations K291E and D45K show enhanced PM localization but D45K significantly reduced VLP formation.
Department of Physics, Florida International University, Miami, Florida, 33199.
Jeevan B
JB
Gc
Department of Chemistry and Biochemistry, the Eck Institute for Global Health, University of Notre Dame, Notre Dame, Indiana, 46556.|Boler-Parseghian Center for Rare and Neglected Diseases, University of Notre Dame, Notre Dame, Indiana, 46556.
Kristen A
KA
Johnson
Department of Chemistry and Biochemistry, the Eck Institute for Global Health, University of Notre Dame, Notre Dame, Indiana, 46556.|Boler-Parseghian Center for Rare and Neglected Diseases, University of Notre Dame, Notre Dame, Indiana, 46556.
Monica L
ML
Husby
Department of Chemistry and Biochemistry, the Eck Institute for Global Health, University of Notre Dame, Notre Dame, Indiana, 46556.|Boler-Parseghian Center for Rare and Neglected Diseases, University of Notre Dame, Notre Dame, Indiana, 46556.
Cary T
CT
Frick
Department of Physics, Florida International University, Miami, Florida, 33199.|Biomolecular Science Institute, Florida International University, Miami, Florida, 33199.
Bernard S
BS
Gerstman
Department of Chemistry and Biochemistry, the Eck Institute for Global Health, University of Notre Dame, Notre Dame, Indiana, 46556.|Boler-Parseghian Center for Rare and Neglected Diseases, University of Notre Dame, Notre Dame, Indiana, 46556.|Department of Biochemistry and Molecular Biology, Indiana University School of Medicine-South Bend, South Bend, Indiana, 46617.
Robert V
RV
Stahelin
Department of Physics, Florida International University, Miami, Florida, 33199.|Biomolecular Science Institute, Florida International University, Miami, Florida, 33199.
Prem P
PP
Chapagain
D019943:Amino Acid Substitution; D002462:Cell Membrane / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D029043:Ebolavirus / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D057809:HEK293 Cells; D006801:Humans; D020125:Mutation, Missense; D000072417:Protein Domains; D055503:Protein Multimerization; D014763:Viral Matrix Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism
C080981:VP40 protein, virus; D014763:Viral Matrix Proteins
Ebola Virus; Interdomain salt-bridges; PM localization; VP40; latch-like interaction; transformer protein