From Hot Springs to HIV, Same Protein Complexes Are Hijacked to Promote Viruses

Biologists from Indiana University and Montana State University have discovered a striking connection between viruses such as HIV and Ebola and viruses that infect organisms called archaea that grow in volcanic hot springs.

Despite the huge difference in environments and a 2 billion year evolutionary time span between archaea and humans, the viruses hijack the same set of proteins to break out of infected cells. In eukaryotes - the group that includes plants and animals - and in archaea - micro-organisms with no defined nucleus in their cellular construction - viruses co-opt a group of important protein complexes called the Endosomal Sorting Complexes Required for Transport, or ESCRT.

The researchers were studying Sulfolobus turreted icosahedral virus, or STIV, which infects Sulfolobus solfataricus, a species of archaea called a thermophile that can be found in volcanic springs, such those in Yellowstone National Park. Thermophiles are micro-organisms that survive in extremely hot environments. The researchers found that, as with a range of viruses that infect humans, STIV is also dependent upon its host's ESCRT machinery to complete its life cycle.

"The new work yields insight into the evolution of the relationship between hosts and viruses and, more importantly, presents us with a new and simple model system to study how viruses can hijack and utilize cellular machineries," said Stephen D. Bell from IU.