Related Experiment Videos
The cytoplasmic tails of infectious bronchitis virus E and M proteins mediate their interaction
Emily Corse1, Carolyn E Machamer
1Department of Cell Biology, The Johns Hopkins University School of Medicine, 725 North Wolfe Street, Baltimore, MD 21205, USA.
Abstract:
Virus-like particle (VLP) formation by the coronavirus E and M proteins suggests that interactions between these proteins play a critical role in coronavirus assembly. We studied interactions between the infectious bronchitis virus (IBV) E and M proteins using in vivo crosslinking and VLP assembly assays. We show that IBV E and M can be crosslinked to each other in IBV-infected and transfected cells, indicating that they interact. The cytoplasmic tails of both proteins are important for this interaction. We also examined the ability of the mutant and chimeric E and M proteins to form VLPs. IBV M proteins that are missing portions of their cytoplasmic tails or transmembrane regions were not able to support VLP formation, regardless of their ability to be crosslinked to IBV E. Interactions between the E and M proteins and the membrane bilayer are likely to play an important role in VLP formation and virus budding.
Insights
Interactions between coronavirus E and M proteins are crucial for virus assembly. Specific regions of these proteins, particularly their cytoplasmic tails, are essential for virus-like particle (VLP) formation and virus budding.
Area of Science:
- Virology
- Molecular Biology
- Structural Biology
Background:
- Coronavirus assembly relies on interactions between the E (envelope) and M (matrix) proteins.
- Virus-like particle (VLP) formation is a key indicator of viral assembly processes.
Purpose of the Study:
- To investigate the interactions between the infectious bronchitis virus (IBV) E and M proteins.
- To determine the role of specific protein domains in VLP formation and coronavirus assembly.
Main Methods:
- In vivo crosslinking assays to detect protein-protein interactions.
- Virus-like particle (VLP) assembly assays using mutant and chimeric E and M proteins.
Main Results:
- The IBV E and M proteins were shown to interact in infected and transfected cells.
- Cytoplasmic tails of both E and M proteins are critical for their interaction.
- Mutations in the cytoplasmic tails or transmembrane regions of M protein abolished VLP formation, irrespective of E protein interaction.
Conclusions:
- Interactions between IBV E and M proteins are essential for VLP formation.
- Specific domains, including cytoplasmic tails and transmembrane regions, are vital for E-M protein interaction and VLP assembly.
- The interplay between E and M proteins and the membrane bilayer is critical for efficient virus budding.