Scientists found new protein factors to control bacterial growth

It is well-known by those biochemists that crucial cell processes depend on a highly regulated cleanup system known as proteolysis, where specialized proteins called proteases degrade damaged or no-longer-needed proteins. These proteases must destroy their own targets but not damage other proteins. However, the process is still not very clear to the in many cases.
Recently, researchers in Peter Chien's group from the department of biochemistry and molecular biology at the University of Massachusetts Amherst report that they have found how an essential bacterial protease controls cell growth and division. You can read the details in the current issue of Cell.
The lead author of the report is Kamal Joshi, a doctoral candidate in the Chien lab. He conducted experiments in the model bacterium Caulobacter crescentus. In this species, the ability to grow and replicate DNA is regulated by ClpXP, a highly conserved protease that in many bacteria allows them to cope with stressful environments such as the human body. Understanding how ClpXP is controlled could open a path to antibiotics that inhibit harmful bacteria in new ways.
How proteolysis controls Caulobacter growth is still a secret in the field.
It is strange that ClpXP only destroys its target proteins at a specific time. They think there must be a factor they've ignored. There are some genetic evidence pointing to certain additional proteins, but no more details are discovered.
The lab purified all available proteins and designing experiments to query how they interacted and what functions were affected in their presence or absence. They found that the ClpXP protease could not by itself destroy the target proteins, and the additional regulatory proteins they had detected were controlling different parts of the process.
Later, they found these newly identified regulatory adaptors worked in a step-wise hierarchical way. The first adaptor was directly responsible for degrading a handful of proteins, but it could also recruit an additional adaptor that would deliver a different set of proteins and bind even more adaptors. Working with the Viollier lab from the University of Geneva, Switzerland, the researchers found scores of additional protease targets that were destroyed in this hierarchical way.
It is believed that this new fundamental knowledge may offer an entirely new target for developing new antibiotics with a high potential to avoid triggering drug resistance, because new compounds could be devised which would not simply target all bacterial growth, but only a specific pathway, such as virulence.
You don't force the benign bacteria to develop resistance in this approach because their growth isn't threatened. The hope is to target only those pathogenic organisms that are trying to overcome the stressful environment inside the human body.
Though the researchers haven't known if these adaptor factors are common among all bacteria, but they decide to figure out.
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