The Science

Viruses affect prevalent microbial systems by killing hosts, transferring genes laterally, and altering cellular metabolism, all of which affect carbon/nitrogen cycles in nature. A virus-infected cell, or “virocell,” is distinct from its uninfected sister cell because the virus controls cellular metabolism to produce viruses rather than replicate cells, yet how virocells respond to nutrient-limited conditions in nature is sparsely investigated. In a recent study, researchers infected marine bacteria Pseudoalteromonas with two different viruses and monitored their metabolism changes under different phosphate levels. This systems biology approach revealed that when nutrients are limited in nature, virocells opt for replication over managing available resource and energy needs.

The Impact

These results suggest that although environmental conditions shape metabolism in common ways regardless of infection, virocell-specific strategies exist to support viral replication during nutrient limitation, and a framework now exists for identifying metabolic strategies of nutrient-limited virocells in nature.

Summary

Viruses play various roles in nature, and their actions inside of hosts are critical in carbon/nitrogen cycles, especially in a marine environment. Virocells, or virus-infected cells, have distinctly different metabolisms than their uninfected sister cells. The present study used a systems biology approach to investigate virocell metabolic reprogramming under nutrient limitation. Using transcriptomics, proteomics, lipidomics, and metabolomics, researchers assessed how low phosphate (low-P) conditions affected virocells of a marine bacteria host, Pseudoalteromonas, when independently infected by two unrelated phages. Based on observations, researchers found that a low-P environment elicited a combination of common and infection-specific responses, and in some cases, even different responses from two different virus types for their replications. This new knowledge allowed researchers to create a framework in which to more easily identify metabolic strategies of virocells in nature when nutrients are limited.

PNNL Contacts

Joshua N Atkins, Pacific Northwest National Laboratory, joshua.adkins@pnnl.gov
Young-Mo Kim, Pacific Northwest National Laboratory, young-mo.kim@pnnl.gov

Funding

This work was supported by the Department of Energy’s (DOE) Facilities Integrating Collaborations for User Science program led by the Environmental Molecular Sciences Laboratory and the Joint Genome Institute, which are DOE Office of Science user facilities. This work was also funded by the Gordon and Betty Moore Foundation, the National Science Foundation, National Institutes of Health, and the University of Michigan.