German virologists from the Universities of Lübeck and Ludwig-Maximilian in Munich, together with colleagues from China and Switzerland, have found out why the coronavirus multiplies rapidly in the body.
In the new work, scientists have established that the unique region of the SARS genome (SUD) and its protein products are responsible for the extraordinary pathogenicity of the SARS-CoV-2 virus, which causes the disease COVID-19.
The researchers found that in infected cells, the SUD proteins interact with the human Paip-1 protein to create a complex that is then involved in the synthesis of viral proteins. Together with Paip-1 and other proteins in human cells, SUD binds to ribosomes, the molecular machines responsible for protein synthesis in cells. As a result, the production of all types of proteins is enhanced – both proteins of the host cell and proteins of the virus.
However, if we are talking about cells infected with coronavirus, then messenger RNA molecules encoding host proteins are selectively destroyed by the viral protein Nsp1.
After this complex process, the infected cell produces predominantly viral proteins. Therefore, the coronavirus, in other words, reprograms host cell proteins and makes them work for itself. This greatly enhances replication – the process of forming new copies of the virus.
Studying these kinds of interactions between coronavirus proteins and the proteins of an infected human cell helps us understand how viruses alter key cell functions in their favor.
Albrecht von Brunn, Doctor and Research Director at Ludwig-Maximilian University