Cytoplasmic tails of bunyavirus Gn glycoproteins—Could they act as matrix protein surrogates?

Viruses of the family Bunyaviridae are negative-sense RNA viruses (NRVs). Unlike other NRVs bunyaviruses do not possess a matrix protein, which typically facilitates virus release from host cells and acts as an anchor between the viral membrane and its genetic core. Therefore the functions of matrix protein in bunyaviruses need to be executed by other viral proteins. In fact, the cytoplasmic tail of glycoprotein Gn (Gn-CT) of various bunyaviruses interacts with the genetic core (nucleocapsid protein and/or genomic RNA). In addition the Gn-CT of phleboviruses (a genus in the family Bunyaviridae) has been demonstrated to be essential for budding. This review brings together what is known on the role of various bunyavirus Gn-CTs in budding and assembly, and hypothesizes on their yet unrevealed functions in viral life cycle by comparing to the matrix proteins of NRVs.

► Bunyaviruses do not have a matrix protein unlike other negative-sense RNA viruses.
► We review the functions of bunyavirus glycoprotein Gn cytoplasmic tail.
► The cytoplasmic tail of Gn is probably required for budding and assembly.
► The cytoplasmic tail of bunyavirus Gn acts as a surrogate matrix protein.
► We hypothesize on the yet unrevealed functions of the cytoplasmic tail.