Bacteria have always been considered harmful and something to be avoided, but according to a recent study by the University of Colorado Boulder, bacteria might just hold the key to unlocking novel approaches to treating various human diseases. The research reveals that bacteria and human cells possess the same core machinery required to switch immune pathways on and off, meaning that studying bacterial processes could provide valuable insights into the human body’s workings. Moreover, researchers found that bacteria use ubiquitin transferases – a cluster of enzymes – to help cGAS (cyclic GMP-AMP synthase) defend the cell from viral attack. Understanding and reprogramming this machine could pave the way for treating various human diseases such as Parkinson’s and autoimmune disorders.
CRISPR, a gene-editing tool, won the Nobel Prize in 2020 for repurposing an obscure system bacteria used to fight off their own viruses. This system’s buzz reignited scientific interest in the role proteins and enzymes play in anti-phage immune response. Aaron Whiteley, senior author and assistant professor in the Department of Biochemistry, said that the potential of this discovery is much bigger than CRISPR. The team discovered two key components, Cap2 and Cap3 (CD-NTase-associated protein 2 and 3), which serve as on and off switches for the cGAS response. Understanding how this machine works and identifying specific components could allow scientists to program the off switch to edit out problem proteins and treat diseases in humans.
This discovery opens new avenues of research as bacteria are easier to genetically manipulate and study than human cells. Whiteley said that the more scientists understand about ubiquitin transferases and how they evolved, the better equipped the scientific community is to target these proteins therapeutically. The study provides clear evidence that the machines in the human body that are important for just maintaining the cell started out in bacteria, doing some really exciting things. The ubiquitin transferases in bacteria are a missing link in our understanding of the evolutionary history of these proteins. Thus, this research shows the importance of studying evolutionary biology, and how it can provide valuable insights into human health.
The study highlights the similarities between bacteria and human cells in terms of their immune response, specifically, describing how cGAS (cyclic GMP-AMP synthase), a protein critical for mounting a downstream defense when the cell senses a viral invader, is present in both bacteria and humans. This similarity suggests that portions of the human immune system may have originated in bacteria, a concept explored in the evolutionary biology unit. In this past unit, we discussed the origins of life, and how all life originated from a simple bacteria cell. This bacteria cell, though many many many repeated cycles of evolution and natural selection allowed for variation within its species and the formation of new species through the processes of speciation.