Researchers at the University of Hawai'i at Mānoa have discovered that a virus from the ocean, named FloV-SA2, carries genetic instructions for producing part of a ribosome, a vital cell component responsible for protein synthesis. This finding marks the first instance of a virus infecting eukaryotic organisms, such as plants and animals, exhibiting this capability.
Viruses consist of genetic material encased in a protein shell and replicate by commandeering host cell machinery. While simpler viruses depend entirely on their host's resources, larger viruses, like FloV-SA2, can synthesize some components independently.
Julie Thomy, the study's lead author and a postdoctoral researcher at the Daniel K. Inouye Center for Microbial Oceanography, expressed enthusiasm over the discovery of a ribosomal protein called eL40 encoded by FloV-SA2. “It makes sense that a virus could benefit from altering this critical piece of cell machinery, but there was just no evidence for it in any eukaryotic virus,” she stated.
The virus was identified during a broader initiative by the Marine Viral Ecology Laboratories to isolate and characterize new oceanic viruses. Christopher Schvarcz, a former oceanography graduate student, sampled water from Station ALOHA, located 60 miles north of Oʻahu, and isolated various viruses, including FloV-SA2, which infects the phytoplankton species Florenciella.
Grieg Steward, a faculty member overseeing the project, noted that viruses play a crucial role in ocean ecosystems, affecting biological productivity and community interactions. “This discovery reveals new details about the complex ways viruses in the ocean interact with phytoplankton, which are the foundation of ocean ecosystems, but it also opens new avenues in our understanding of the fundamentals of viral biology,” he explained.
The researchers anticipate that FloV-SA2 will serve as a valuable model for exploring how viruses manipulate cellular metabolism and redirect host resources. Previous studies have indicated that other “giant” viruses also code for proteins involved in diverse metabolic functions, raising questions about their replication processes.
Thomy added, “Our working hypothesis is that by inserting one of its own proteins into the ribosome, the virus alters this key piece of machinery to favor the production of virus proteins over the usual cell proteins.”