Biochemists at the University of Massachusetts have recently made discoveries about protein involvement with cell division, according to a UMass press release.
The team of involved researchers, which includes assistant professor Peter Chien, has distinguished a process by which proteins “shelter each other,” allowing for cell division to be smooth and error-free, the release said.
According to Chien in the release, the purpose of the experiments which led to this discovery was to uncover “all the steps and back-up safeguards that cells use to robustly protect replication while at the same time allowing other functions to proceed.”
The release states that this study reveals the synthesis and degradation of two particular proteins – CtrA and SciP – which are crucial for regular cellular division. These proteins mutually assure that neither will be dissolved prior to and following DNA replication.
Proteases, which are protein-dissolving enzymes, are the chemical that “cut up and recycle used proteins,” according to the release. The issue for the team of biochemical researchers is that some proteins can go from being essential for regular cellular function at one particular moment, but then can be “toxic garbage,” to the cell at another, according to the release.
In order to differentiate waste proteins from useful ones, the UMass researchers collaborated with members of Michael Laub’s research team at MIT to isolate the two proteins in a strain of bacteria called Caulobacter crescentus, according to the release.
The release said that CtrA binds itself to the ends of a strand of DNA, “controlling replication until conditions are right for division to occur,” adding that “destruction of CtrA allows cells to start replicating their chromosome.”
The researchers at UMass showed that CtrA is only degraded when bound to a DNA molecule, and that the second protein, SciP, helps bind CtrA more effectively to DNA and makes the protein more resistant to proteolysis – breakdown by enzymes.
Additionally, the researchers found that this process made SciP less likely to be subject to proteolysis, showing that “both proteins prevent their own destruction by protecting each other,” according to the release.
The importance of this work comes with the fact that these findings, according to the release, “may offer medical researchers a clue for understanding diseases such as abnormal cell cycle progression in cancer.”
The work and experiments conducted by Chien and the team of UMass researchers was funded by grants from UMass as well as the National Institutes of Health.
George Felder can be reached at [email protected].