Rhabdovirus accessory genes

Abstract

The Rhabdoviridae is one of the most ecologically diverse families of RNA viruses with members infecting a wide range of organisms including placental mammals, marsupials, birds, reptiles, fish, insects and plants. The availability of complete nucleotide sequences for an increasing number of rhabdoviruses has revealed that their ecological diversity is reflected in the diversity and complexity of their genomes. The five canonical rhabdovirus structural protein genes (N, P, M, G and L) that are shared by all rhabdoviruses are overprinted, overlapped and interspersed with a multitude of novel and diverse accessory genes. Although not essential for replication in cell culture, several of these genes have been shown to have roles associated with pathogenesis and apoptosis in animals, and cell-to-cell movement in plants. Others appear to be secreted or have the characteristics of membrane-anchored glycoproteins or viroporins. However, most encode proteins of unknown function that are unrelated to any other known proteins. Understanding the roles of these accessory genes and the strategies by which rhabdoviruses use them to engage, divert and re-direct cellular processes will not only present opportunities to develop new anti-viral therapies but may also reveal aspects of cellar function that have broader significance in biology, agriculture and medicine.

ICTV Virus Taxonomy Profile: Rhabdoviridae

“…Genomes usually encode five major structural proteins but may also encode additional (accessory) proteins either in additional genes or as alternative ORFs within the structural protein genes (Fig. 2) [1,3].…”

Roles of nuclear trafficking in infection by cytoplasmic negative-strand RNA viruses: paramyxoviruses and beyond

“…Accessory proteins are encoded by genes additional to the usual genome complement, such as non-structural 1 and 2 proteins and short hydrophobic protein variously found in members of the Paramyxoviridae and a diverse array of accessory genes found in certain rhabdoviruses (Goodbourn & Randall, 2009;Walker et al, 2011), or are encoded as alternative products within conserved structural protein genes. In RABV and viruses of the subfamily Paramyxovirinae, accessory proteins are encoded in the P gene in addition to the principal encoded protein P, the viral polymerase co-factor.…”

Merida virus, a putative novel rhabdovirus discovered in Culex and Ochlerotatus spp. mosquitoes in the Yucatan Peninsula of Mexico

“…Each ORF is flanked by relatively conserved cis-acting transcription initiation and transcription termination/polyadenylation signals that regulate mRNA expression. Rhabdovirus genomes are often interspersed with smaller ORFs that encode accessory proteins, most of which are of unknown function (Walker et al, 2011). ORFs that encode accessory proteins can occur as alternative or overlapping ORFs within the major structural protein genes or as independent ORFs in the intergenic regions that separate the structural protein genes.…”