October 4, 2019 | Jola Glotzer
Dynamic tuning of environmental sensitivity
CBC Junior Investigator Michael Rust, UChicago, contributes to a recent Cell Systems study addressing the mechanisms of organismal sensitivity to changing environment
It may (or may not) be surprising to learn that, as a species, humans are constantly adapting to the ever-changing environment that surrounds us; the principle of continuous adaptation. In fact, all living organisms must be able to adapt, and, hence be equipped with sensitive detectors of environmental changes. Moreover, to adequately respond, an organism has to be able to pick up just the relevant signals while tuning out the so-called “noise.”
These are the types of problems that are addressed in a recent Cell Systems publication, titled “Kalman-like Self-Tuned Sensitivity in Biophysical Sensing.” (For those who are not familiar with Kalman filtering, see Wikipedia.)
Synechococcus elongatus, a freshwater unicellular cyanobacterium, and yeast are used as model systems to study organismal adaptation to day-night light cycle and osmotic-stress-response pathway, respectively. Based on the reported findings implications for other experimental systems are also discussed.
A co-author on the paper, Michael Rust, is Associate Professor at the Department of Molecular Genetics and Cell Biology and a member of the Institute for Genomics and Systems Biology at UChicago. Rust has multiple ties to CBC. He received three CBC awards: a Catalyst in 2016, a Postdoctoral Research Award in 2014, and a Recruitment Resources Award in 2011. With the latter award, Rust became a CBC Junior Investigator. In addition, since 2017, he has served on the CBC Catalyst Review Board. CBC appreciates Michael’s time and dedication and joins in congratulating him and the other co-authors on the current study.
Publication linked to the *CBC funding:
Husain K, Pittayakanchit W, Pattanayak G, Rust MJ, Murugan A. Kalman-like Self-Tuned Sensitivity in Biophysical Sensing. Cell Syst. 2019 Sep 12. [Epub ahead of print] (PubMed)
Living organisms need to be sensitive to a changing environment while also ignoring uninformative environmental fluctuations. Here, we argue that living cells can navigate these conflicting demands by dynamically tuning their environmental sensitivity. We analyze the circadian clock in Synechococcus elongatus, showing that clock-metabolism coupling can detect mismatch between clock predictions and the day-night light cycle, temporarily raise the clock’s sensitivity to light changes, and thus re-entraining faster. We find analogous behavior in recent experiments on switching between slow and fast osmotic-stress-response pathways in yeast. In both cases, cells can raise their sensitivity to new external information in epochs of frequent challenging stress, much like a Kalman filter with adaptive gain in signal processing. Our work suggests a new class of experiments that probe the history dependence of environmental sensitivity in biophysical sensing mechanisms.
Featured CBC Community member(s):
ARTICLES PUBLISHED IN THE PAST ABOUT THE FEATURED CBC COMMUNITY MEMBER(S):
October 1, 2018
▸ Mechanics of actin-microtubule composites
Explained in recent Scientific Reports paper, by a CBC Junior Investigator Michael Rust, UChicago, and his collaborators
August 8, 2018
▸ Tick, tock, tick, tock
Michael Rust, UChicago, who has many ties to CBC, explains two types of circadian “clocks”