scholarly journals Interdomain salt-bridges in the Ebola virus protein VP40 and their role in domain association and plasma membrane localization

2016 ◽  
Vol 25 (9) ◽  
pp. 1648-1658 ◽  
Author(s):  
Jeevan B. GC ◽  
Kristen A. Johnson ◽  
Monica L. Husby ◽  
Cary T. Frick ◽  
Bernard S. Gerstman ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Ebola Virus ◽  
Membrane Localization ◽  
Virus Protein ◽  
Salt Bridges ◽  
Plasma Membrane Localization

scholarly journals A Conserved Tryptophan in the Ebola Virus Matrix Protein C-Terminal Domain Is Required for Efficient Virus-Like Particle Formation

Pathogens ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 402 ◽  
Author(s):  
Kristen A. Johnson ◽  
Rudramani Pokhrel ◽  
Melissa R. Budicini ◽  
Bernard S. Gerstman ◽  
Prem P. Chapagain ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Matrix Protein ◽  
Ebola Virus ◽  
Membrane Localization ◽  
Virus Like Particles ◽  
Plasma Membrane Localization ◽  
The Matrix ◽  
Dynamics Simulations

The Ebola virus (EBOV) harbors seven genes, one of which is the matrix protein eVP40, a peripheral protein that is sufficient to induce the formation of virus-like particles from the host cell plasma membrane. eVP40 can form different structures to fulfil different functions during the viral life cycle, although the structural dynamics of eVP40 that warrant dimer, hexamer, and octamer formation are still poorly understood. eVP40 has two conserved Trp residues at positions 95 and 191. The role of Trp95 has been characterized in depth as it serves as an important residue in eVP40 oligomer formation. To gain insight into the functional role of Trp191 in eVP40, we prepared mutations of Trp191 (W191A or W191F) to determine the effects of mutation on eVP40 plasma membrane localization and budding as well as eVP40 oligomerization. These in vitro and cellular experiments were complemented by molecular dynamics simulations of the wild-type (WT) eVP40 structure versus that of W191A. Taken together, Trp is shown to be a critical amino acid at position 191 as mutation to Ala reduces the ability of VP40 to localize to the plasma membrane inner leaflet and form new virus-like particles. Further, mutation of Trp191 to Ala or Phe shifted the in vitro equilibrium to the octamer form by destabilizing Trp191 interactions with nearby residues. This study has shed new light on the importance of interdomain interactions in stability of the eVP40 structure and the critical nature of timing of eVP40 oligomerization for plasma membrane localization and viral budding.

scholarly journals Lipid binding by the N-terminal motif mediates plasma membrane localization of Bordetella effector protein BteA

2021 ◽  
pp. 100607
Author(s):  
Ivana Malcova ◽  
Ladislav Bumba ◽  
Filip Uljanic ◽  
Darya Kuzmenko ◽  
Jana Nedomova ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Lipid Binding ◽  
Membrane Localization ◽  
Effector Protein ◽  
Plasma Membrane Localization

scholarly journals Palmitoylation of Sindbis Virus TF Protein Regulates Its Plasma Membrane Localization and Subsequent Incorporation into Virions

2016 ◽  
Vol 91 (3) ◽  
Author(s):  
Jolene Ramsey ◽  
Emily C. Renzi ◽  
Randy J. Arnold ◽  
Jonathan C. Trinidad ◽  
Suchetana Mukhopadhyay
Keyword(s):  
Plasma Membrane ◽  
Sindbis Virus ◽  
Molecular Mechanisms ◽  
Wild Type Virus ◽  
Membrane Localization ◽  
Clear Understanding ◽  
Wild Type ◽  
Plasma Membrane Localization ◽  
C Terminus ◽  
N Terminus

ABSTRACT Palmitoylation is a reversible, posttranslational modification that helps target proteins to cellular membranes. The alphavirus small membrane proteins 6K and TF have been reported to be palmitoylated and to positively regulate budding. 6K and TF are isoforms that are identical in their N termini but unique in their C termini due to a −1 ribosomal frameshift during translation. In this study, we used cysteine (Cys) mutants to test differential palmitoylation of the Sindbis virus 6K and TF proteins. We modularly mutated the five Cys residues in the identical N termini of 6K and TF, the four additional Cys residues in TF's unique C terminus, or all nine Cys residues in TF. Using these mutants, we determined that TF palmitoylation occurs primarily in the N terminus. In contrast, 6K is not palmitoylated, even on these shared residues. In the C-terminal Cys mutant, TF protein levels increase both in the cell and in the released virion compared to the wild type. In viruses with the N-terminal Cys residues mutated, TF is much less efficiently localized to the plasma membrane, and it is not incorporated into the virion. The three Cys mutants have minor defects in cell culture growth but a high incidence of abnormal particle morphologies compared to the wild-type virus as determined by transmission electron microscopy. We propose a model where the C terminus of TF modulates the palmitoylation of TF at the N terminus, and palmitoylated TF is preferentially trafficked to the plasma membrane for virus budding. IMPORTANCE Alphaviruses are a reemerging viral cause of arthritogenic disease. Recently, the small 6K and TF proteins of alphaviruses were shown to contribute to virulence in vivo. Nevertheless, a clear understanding of the molecular mechanisms by which either protein acts to promote virus infection is missing. The TF protein is a component of budded virions, and optimal levels of TF correlate positively with wild-type-like particle morphology. In this study, we show that the palmitoylation of TF regulates its localization to the plasma membrane, which is the site of alphavirus budding. Mutants in which TF is not palmitoylated display drastically reduced plasma membrane localization, which effectively prevents TF from participating in budding or being incorporated into virus particles. Investigation of the regulation of TF will aid current efforts in the alphavirus field searching for approaches to mitigate alphaviral disease in humans.

scholarly journals A novel RCE1 isoform is required for H-Ras plasma membrane localization and is regulated by USP17

2013 ◽  
Vol 457 (2) ◽  
pp. 289-300 ◽  
Author(s):  
Jakub Jaworski ◽  
Ureshnie Govender ◽  
Cheryl McFarlane ◽  
Michelle de la Vega ◽  
Michelle K. Greene ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Membrane Localization ◽  
Plasma Membrane Localization

We have identified a novel RCE1 isoform which is required for proper H-Ras processing and plasma membrane localization. In addition, we have shown that USP17 can regulate this novel isoform and thus RCE1 activity by deubiquitinating Lys43.

scholarly journals Role of Ezrin/Radixin/Moesin in the Surface Localization of Programmed Cell Death Ligand-1 in Human Colon Adenocarcinoma LS180 Cells

2021 ◽  
Vol 14 (9) ◽  
pp. 864
Author(s):  
Takuro Kobori ◽  
Chihiro Tanaka ◽  
Mayuka Tameishi ◽  
Yoko Urashima ◽  
Takuya Ito ◽  
...  
Keyword(s):  
Cell Death ◽  
Plasma Membrane ◽  
Programmed Cell Death ◽  
Cell Surface ◽  
Actin Cytoskeleton ◽  
Mrna Level ◽  
Scaffold Proteins ◽  
Membrane Localization ◽  
Erm Proteins ◽  
Plasma Membrane Localization

Programmed cell death ligand-1 (PD-L1), an immune checkpoint protein highly expressed on the cell surface in various cancer cell types, binds to programmed cell death-1 (PD-1), leading to T-cell dysfunction and tumor survival. Despite clinical successes of PD-1/PD-L1 blockade therapies, patients with colorectal cancer (CRC) receive little benefit because most cases respond poorly. Because high PD-L1 expression is associated with immune evasion and poor prognosis in CRC patients, identifying potential modulators for the plasma membrane localization of PD-L1 may represent a novel therapeutic strategy for enhancing the efficacy of PD-1/PD-L1 blockade therapies. Here, we investigated whether PD-L1 expression in human colorectal adenocarcinoma cells (LS180) is affected by ezrin/radixin/moesin (ERM), functioning as scaffold proteins that crosslink plasma membrane proteins with the actin cytoskeleton. We observed colocalization of PD-L1 with all three ERM proteins in the plasma membrane and detected interactions involving PD-L1, the three ERM proteins, and the actin cytoskeleton. Furthermore, gene silencing of ezrin and radixin, but not of moesin, substantially decreased the expression of PD-L1 on the cell surface without affecting its mRNA level. Thus, in LS180 cells, ezrin and radixin may function as scaffold proteins mediating the plasma membrane localization of PD-L1, possibly by post-translational modification.

Sign in / Sign up

Export Citation Format

Share Document