Related Experiment Videos
Semliki Forest virus envelope proteins function as proton channels
A Schlegel1, A Omar, P Jentsch
1Central Laboratory Blood Transfusion Service, Swiss Red Cross, Bern.
Bioscience Reports
|October 1, 1991
Summary
Semliki Forest virus (SFV) nucleocapsids contract at low pH, indicating spike proteins translocate protons. Spikeless particles showed no proton translocation, highlighting the spike protein's ectodomain role in this process.
Area of Science:
- Virology
- Molecular Biology
- Biophysics
Background:
- Semliki Forest virus (SFV) nucleocapsids exhibit pH-dependent contraction.
- Proton translocation across viral envelopes is crucial for infection.
- The role of SFV spike proteins in proton transport remained unclear.
Purpose of the Study:
- To investigate the role of Semliki Forest virus spike proteins in proton translocation.
- To determine if the viral spike protein ectodomain is essential for low pH-induced proton transport.
Main Methods:
- Isolated Semliki Forest virus nucleocapsids were exposed to low pH conditions.
- Proton translocation was measured using the contraction of nucleocapsids as an indicator.
- Spikeless virus particles, generated by bromelain digestion, served as control experiments.
Main Results:
- Isolated SFV nucleocapsids contracted significantly upon exposure to low pH (5.8).
- This contraction demonstrated proton translocation into the virus interior, mediated by spike proteins.
- Spikeless virus particles did not exhibit proton translocation, confirming the necessity of spike proteins.
Conclusions:
- The spike proteins of Semliki Forest virus are responsible for proton translocation into the virion at low pH.
- The ectodomain of the SFV spike protein plays a critical role in facilitating proton transport.
- These findings provide insights into the mechanism of viral entry and genome release.