Join us on Monday, February 02 for a talk by Postdoc Award Winner Kirti Jain. She will be speaking on “Basal Gene Expression Dynamics in Bacteria”.
The event begins with a reception in the foyer of RLH at 11:00 AM, followed by the talk at 11:30 AM. We look forward to seeing you there!
Kirti (now Alum from Guet group) is one of the two winners alongside Shengduo Xu (also Alum, from Ibañez group) of the new Postdoc Award at ISTA.
Please join the rest of the ISTA community to celebrate her achievements and also take advantage of this opportunity to have a chat with her afterwards about her accomplishments beyond ISTA now as Alum!
Click here to add this talk to your calendar.
The multiple antibiotic resistance (mar) operon is one of the largest regulons in Escherichia coli. The mar locus encodes an autorepressor, MarR; an autoactivator, MarA; and MarB, a protein of unknown function and via MarA regulates a wide variety of downstream targets involved in cellular processes such as efflux, pH response, porin regulation, etc. Although this system has been extensively studied for its role in antibiotic resistance, the role of basal expression has largely been overlooked and dismissed as promoter leakiness.
Our work explores the basal expression mode of the mar operon and shows that it is dynamic, consisting of rare stochastic gene expression pulses. These pulses maximize phenotypic variability in wild-type populations and, unexpectedly, transiently accelerate cellular elongation rates. At the molecular level, this behavior is linked to an unusual yet evolutionarily conserved GTG start codon in marR, suggesting that natural selection has preserved this dynamic expression pattern across many related gut bacteria. Together, these findings demonstrate that even so-called “leaky” uninduced gene expression can be a selected feature with meaningful ecological and physiological consequences, reshaping our understanding of gene regulation in microbes.