Rubella E2

Rubella virus (RuV) is a positive-strand RNA virus that belongs to the genus Rubivirus in the family Matonaviridae . It is an enveloped virus that primarily infects humans, causing mild disease in children and adults. However, infection during pregnancy can lead to severe congenital birth defects or miscarriage . The virus is known for its ability to cross the placenta and cause congenital rubella syndrome (CRS), which includes a range of serious birth defects .

The E2 protein is one of the two major envelope glycoproteins of the rubella virus, the other being E1 . The E2 protein plays a crucial role in the virus’s life cycle, including virus assembly, budding, and interaction with the host cell . It is a type I membrane protein that undergoes posttranslational modifications, including glycosylation . The E2 protein is essential for the virus’s ability to infect host cells and propagate.

Recombinant E2 protein refers to the E2 protein that has been produced using recombinant DNA technology. This involves inserting the gene encoding the E2 protein into a suitable expression system, such as insect cells or mammalian cells, to produce the protein in large quantities . The recombinant E2 protein is often used in research to study the virus’s structure and function, as well as in the development of vaccines and diagnostic tools.

The E2 protein contains a potential late domain motif (278 PPAY 281) at its C-terminus, which is crucial for virus budding . This motif can promote virus budding by recruiting the cellular ESCRT machinery, although rubella virus appears to be ESCRT-independent . Mutations in the E2 protein, such as the Y281A mutation, can significantly reduce virus production and affect the interaction between the E2 protein and the capsid protein . These interactions are essential for the localization of the capsid protein to the Golgi apparatus, where virus budding occurs .

The E2 protein of rubella virus shares similarities with the E2 proteins of other rubiviruses, such as the recently discovered Ruhugu virus (RuhV) and Rustrela virus (RusV) . These viruses highlight the spillover potential of rubiviruses from animals to humans . The evolutionary relationship between these viruses is supported by the presence of similar motifs and functional domains in their E2 proteins .

Recombinant E2 protein is used in various applications, including:

• Vaccine Development: The E2 protein is a target for vaccine development due to its role in virus entry and immune response induction .
• Diagnostic Tools: Recombinant E2 protein can be used to develop diagnostic assays for detecting rubella virus infections .
• Research: Studying the recombinant E2 protein helps researchers understand the virus’s life cycle, assembly, and interactions with host cells .