Erika Smith
In response to environmental stressors such as nutrient deprivation, bacteria activate a conserved stress response pathway called the stringent response (SR). In addition to stress survival in non-pathogenic contexts, SR activation is implicated in the virulence and antibiotic tolerance of pathogens. In the Goley lab, we use the freshwater bacterium Caulobacter crescentus as a tractable model to study bacterial adaptation to stress. During SR activation, adaptation and survival are promoted over growth and anabolism. In Caulobacter, a major regulator of anabolic genes is the widely conserved transcription factor CdnL. If and how CdnL is controlled during the SR and why that might be functionally important is unclear. Through my thesis research, I have elucidated the mechanisms contributing to downregulation of CdnL during the SR. Preventing CdnL degradation during nutrient deprivation causes misregulation of ribosomal and metabolic genes. Functionally, I found that CdnL clearance allows for efficient adaptation to nutrient repletion, and that cells with the inability to clear CdnL during starvation are outcompeted by wild-type cells when subjected to nutrient fluctuations. These findings indicate that clearance of CdnL during the SR is critical for altering the transcriptome to permit cell survival during nutrient stress. Because CdnL homologs are broadly found and are in important pathogens such as Borrelia burgdorferi and Mycobacterium tuberculosis, I hypothesize that CdnL regulation is a conserved mechanism of stress adaptation across bacteria.
Questions & Answers
Why did you choose Johns Hopkins for your work?
One of my dreams since high school was to study at Johns Hopkins. Candidly, the inspiration stemmed from my favorite TV show, House, M.D. The main character, infectious disease doctor Gregory House, was supposedly educated at Johns Hopkins, and I, too, wanted to be an infectious disease doctor. In college, my ambitions shifted away from being in the clinic and toward being at the bench. In addition to applying to other graduate schools, I also applied to three graduate programs at Johns Hopkins because there were numerous labs here that excited me. Ultimately, I decided to come because of the collegiality and supportive environment. PI, postdoc or graduate student — people are just nice here.
What does receiving this award mean to you personally and professionally? Do you have any connection with the particular award you received?
I am very honored to have received the Mette Strand Award because I share Dr. Strand’s excitement for studying infectious diseases. As a woman in STEM, I am inspired by Dr. Strand to follow my passion for understanding the molecular mechanisms contributing to pathogenesis and to establish a lab of my own. I hope to be as great of a mentor as Dr. Strand was for her students.
What contributed to your project’s success?
I owe much of the project’s success to my mentor, Dr. Erin Goley. She has been so encouraging of my work, and she always finds time to discuss my data and to help me rationalize the findings. She also has the uncanny ability to remember experiments that I performed even when I do not remember doing them. I really appreciate and admire Erin for being both an excellent mentor and a caring person. Additionally, I have been fortunate to collaborate with many amazing people both here and at other institutions. Dr. Peter Chien at UMass Amherst has been particularly helpful, from “Zooming” into my thesis meetings to Slack messaging Erin and me whenever we wanted his insight. It definitely took a village to raise this child, and I appreciate all of the help and support I have gotten along the way. I also just really love the process of doing experiments and analyzing data, so my work has mostly been performed out of curiosity as opposed to necessity.
What thoughts do you have about Young Investigators’ Day itself, as a celebration of the roles students and fellows play in research at Johns Hopkins?
Young Investigators’ Day is a great way to showcase the diverse research occurring at Johns Hopkins. I admire my peers for their rigor and commitment to their research, and I am very humbled to be a part of this community of dedicated scientists.
What has been your best/most memorable experience while at Johns Hopkins?
Some of my favorite memories include the moments spent with my lab. Whether it is in lab meeting or at a brewery, talking about science or talking about nonsense, it is always so much fun and I truly enjoy being around them. I have also had the opportunity to share my graduate school experience with my twin sister, Danielle Smith, who also received an award this year!
What are your plans over the next year or so? Graduating, looking for faculty positions, etc.?
I will be graduating within the next few months. In August, I will be starting a postdoctoral position in the lab of Dr. Philip Adams at the NIH to study RNA regulation in the Lyme disease pathogen, Borrelia burgdorferi.
Tell me something interesting about yourself that makes you unique. Do you have any special hobbies, interests or life experiences?
Outside of the lab, I love being active and spending time outdoors. The mental clarity that a morning run along the Baltimore waterfront brings me almost always helps me start my day on a good note.