Rubella virus is the only member of the Rubrivirus genus of the Togavirus family. Unlike most Togaviruses it is NOT arthropod borne, but is acquired via the respiratory route. It is an enveloped (toga=cloak), non-segmented, positive sense, RNA virus and replicates in the cytoplasm. It consists of 3 structural proteins; E1,E2 membrane bound glycoproteins, and C capsid protein.
E1 envelope glycoprotein is a class II viral fusion protein. Fusion activity is inactive as long as E1 is bound to E2 in mature virion. After virus attachment to target cell and endocytosis, acidification of the endosome induces dissociation of E1/E2 heterodimer and trimerization of the E1 subunits. This E1 homotrimer is fusion active, and promotes release of viral nucleocapsid in the cytoplasm after cell and viral membrane fusion. The E1 cytoplasmic tail modulates virus release, and the tyrosines residues are critical for this function.
has not yet been referenced specifically in any publications.