Marketed as we’re not all that different from bacteria:
“This study demonstrates that we’re not all that different from bacteria,” said senior author Aaron Whiteley, an assistant professor in the Department of Biochemistry. “We can learn a lot about how the human body works by studying these bacterial processes.”
What was the find?
For the study, Whiteley and co-first author Hannah Ledvina, a Jane Coffin Childs Postdoctoral Fellow in the department, collaborated with University of California San Diego biochemists to learn more about a protein called cGAS (cyclic GMP-AMP synthase), previously shown to be present in both humans and, in a simpler form, bacteria.
In bacteria and in humans, cGAS is critical for mounting a downstream defense when the cell senses a viral invader. But what regulates this process in bacteria was previously unknown.
Using an ultra-high-resolution technique called cryo-electron microscopy alongside other genetic and biochemical experiments, Whiteley’s team took an up-close look at the structure of cGAS’s evolutionary predecessor in bacteria and discovered additional proteins that bacteria use to help cGAS defend the cell from viral attack.
Specifically, they discovered that bacteria modify their cGAS using a streamlined “all-in-one version” of ubiquitin transferase, a complex collection of enzymes that in humans control immune signaling and other critical cellular processes.
Because bacteria are easier to genetically manipulate and study than human cells, this discovery opens a new world of opportunity for research, said Ledvina.
Any life form needs a strategy for dealing with viruses. Humans, bacteria, and perhaps countless other life forms may have hit on the same one.
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