One human protein controls how the coronavirus spreads
Why do some viruses replicate so efficiently that they overwhelm the immune system? In SARS-CoV-2, a single human protein turns out to play a key role at multiple steps of that process. That finding opens a new target for antiviral therapies.
The SARS-CoV-2 coronavirus has found an efficient way to multiply inside human cells. After infection, it hijacks the cell’s own machinery to produce new virus particles. Exactly how this works, and which human proteins are enlisted, has not yet been fully mapped.
ITCH as a central regulator
Researchers identified the protein ITCH as a central regulator of the SARS-CoV-2 life cycle. ITCH is an E3 ubiquitin ligase: a protein that attaches a chemical tag, ubiquitin, to other proteins. That tag marks proteins for degradation or functional change. The study, published in eLife, shows that ITCH does this to multiple viral proteins simultaneously, including the envelope and membrane proteins of the virus.
This means ITCH influences how the virus assembles its outer shell and then exits the cell to infect new ones. Without sufficient ITCH activity, that process becomes less efficient for the virus.
Relevance for aging and infection risk
Older adults are more vulnerable to severe COVID-19. Part of that vulnerability comes from changes in the immune system, but the antiviral machinery inside cells also changes with age. If ITCH plays a central role in how the virus replicates, it is relevant to ask whether ITCH activity shifts with aging.
Practically, the finding offers a potential drug target: blocking or modulating ITCH could limit viral replication. That is a different strategy from vaccines or drugs that attack the virus directly. Whether this approach works in humans still needs investigation.