Name
Fusion-associated small transmembrane (FAST)-like proteins found encoded by viruses of Pistolviridae of order Ghabrivirales
Presenter
Aase B Mikalsen, Norwegian University of Life Sciences
Co-Author(s)
Racheal Amono, Turhan Markussen, Øystein Evensen and Aase B. Mikalsen, Norwegian University of Life Sciences (NMBU), Faculty of Veterinary Sciences, Aquamedicine unit
Abstract Category
Virus Replication: Entry, Exit and Everything in Between
Abstract
FAST-proteins are viral nonstructural proteins that induce cell-cell fusion. These proteins have been well-known for three decades to be encoded by specific viruses of the two Spinareoviridae genera aquareovirus and orthoreovirus. FAST-proteins are the smallest type of viral fusion proteins, which function at neutral pH and without the need for a specific receptor or other type of fusion induction and are specialized for cell-cell fusion with resulting syncytia. Unlike enveloped viruses, naked viruses do not require fusion proteins to enter cells, but such proteins may play a role in spread of the virus. Although not essential for virus replication, FAST proteins enhance viral replication, specifically in the early phases of infection.
More recently the range of virus species that takes advantage of including proteins with similarities to FAST-proteins are increasing and FAST-proteins have now also been described from a few rotavirus species, genus Sedoviridae i.e. under the same Reovirales order and most recently from enveloped viruses within Coronaviridae.
Here we present protein sequence studies suggesting that also viruses of the recently established virus family Pistolviridae, order Ghabrivirales, encode FAST-like proteins, either from a small separate ORF or generated as cleavage peptide products from a polyprotein. Pistolviruses are viruses infecting piscine species and were originally referred to as “toti-like” viruses as they shared some genomic characteristics with viruses of Totiviridae, infecting single-celled organisms.
More recently the range of virus species that takes advantage of including proteins with similarities to FAST-proteins are increasing and FAST-proteins have now also been described from a few rotavirus species, genus Sedoviridae i.e. under the same Reovirales order and most recently from enveloped viruses within Coronaviridae.
Here we present protein sequence studies suggesting that also viruses of the recently established virus family Pistolviridae, order Ghabrivirales, encode FAST-like proteins, either from a small separate ORF or generated as cleavage peptide products from a polyprotein. Pistolviruses are viruses infecting piscine species and were originally referred to as “toti-like” viruses as they shared some genomic characteristics with viruses of Totiviridae, infecting single-celled organisms.