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Cytoplasmic R-peptide of murine leukemia virus envelope protein negatively regulates its interaction with the cell

Yoshinao Kubo1, Mai Izumida2, Kei Togawa1

  • 1Program for Nurturing Global Leaders in Tropical Medicine and Emerging Communicable Diseases, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan.

Virology
|April 30, 2019
PubMed

Insights

The R-peptide in ecotropic murine leukemia virus (E-MLV) Env protein inhibits fusion. Removing this R-peptide enhances Env-receptor binding and E-MLV infection.

Area of Science:

  • Virology
  • Molecular Biology
  • Cell Biology

Background:

  • Retroviral envelope (Env) glycoproteins mediate viral entry.
  • Cytoplasmic tails of Env proteins can inhibit membrane fusion.
  • The R-peptide of ecotropic murine leukemia virus (E-MLV) Env protein is known to inhibit fusion, but its mechanism is unclear.

Purpose of the Study:

  • To elucidate the molecular mechanism by which the R-peptide of E-MLV Env protein inhibits membrane fusion.
  • To investigate the effect of R-peptide truncation on Env-receptor interaction and viral infectivity.

Main Methods:

  • Comparative analysis of Env-receptor binding affinity.
  • Assessment of viral vector infection efficiency.
  • Evaluation of conformational changes in the Env protein.

Main Results:

  • E-MLV Env protein containing the R-peptide exhibited weaker binding affinity to the cationic amino acid transporter-1 (CAT-1) receptor compared to R-peptide-truncated Env.
  • R-peptide-containing Env protein showed less efficient inhibition of E-MLV vector infection.
  • R-peptide truncation was associated with conformational changes in the receptor-binding domain of the E-MLV Env protein.

Conclusions:

  • The R-peptide of E-MLV Env protein inhibits Env-receptor interaction.
  • R-peptide truncation induces conformational changes that facilitate Env-receptor binding.
  • These findings provide insight into the regulation of retroviral membrane fusion and viral entry.
Keywords:
Envelope proteinMurine leukemia virusR-peptideReceptor bindingTransmembrane subunit

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