Congratulations, Dr. Shannon Rivera!

Shannon Rivera

Shannon Rivera successfully defended her dissertation, “Elucidating the Various Roles of the Globin Domain from Globin Coupled Sensors”, on March 21st, 2019. Shannon’s committee was led by Emily Weinert with Brian Dyer and Stefan Lutz as additional members.

During her time at Emory, Shannon was supported by an Emory Graduate Diversity Fellowship as well as a Carl Storm Underrepresented Minority (CSURM) Fellowship. She was also recognized with the department’s Outstanding T.A. Award for Analytical Chemistry in 2014 and the Quayle Outstanding Student Award in 2018.

Shannon has also been involved in several student organizations including Pi Alpha Chemical Society (PACS) where she served for one year as Vice President of Community Service and the Association for Women in Science (AWIS) where she served consecutive terms first as Co-Social Chair and then as Communications Chair. She has also been a long time member of the Chemistry Graduate School Prep Club sponsored by the NSF Center for Selective C-H Functionalization, serving as President in 2017 and 2018. CGSPC connects Atlanta-area undergraduates from PUIs and HBCUs (including Agnes Scott, Spelman, Morehouse, and Clarke-Atlanta) with mentors who help them to connect with mentors who can help them navigate the graduate school application process . Shannon was instrumental in bringing CGSPC students to Emory for an on-site mentoring event. “They got to talk to faculty, grads, and post-docs about admissions and the struggles of being under represented in the sciences. The effect the event had of them and the fact that it cemented the drive to go to graduate school for those students, that is what made it a huge accomplishment for me,” says Shannon.

Scientifically, Shannon’s work was recently recognized with an invitation to give two oral presentations at SERMACS and GRS/GRC Metals in Biology. SERMACS receives well over 1,000 applications for oral applications and awards only 12-15 spots. “Scientifically though, the most fun and impactful accomplishment was successfully crystallizing my protein, BpeGlobin,” says Shannon. “It was fun because my protein is red, so my crystals are red! They came in different shapes, but you could always see them.  It is also very important for my scientific community because its the first crystal of  the signaling domain of a Globin-coupled sensor with oxygen in the pocket; the gas responsible for activating the protein.”

Shannon plans to pursue a career in industry.

Congratulations, Shannon!

Graduate Student Spotlight: Shannon Rivera

Sitting in her 6th grade science classroom, as a gallon of milk sat outside warming under the hot Georgia sun, Shannon learned two things. First, she learned about the effects of high temperatures on the properties and states of liquids. And second, she learned that she really, really loved chemistry. She recalls how the hands-on teaching style in her middle school science classroom sparked her enthusiasm for the subject, an enthusiasm which only grew stronger through high school, where she had the chance to serve as a chemistry teacher’s assistant.

Through these experiences, Shannon gained an understanding of how chemistry can shape the world. “Instead of being a giant jumbled puzzle, you could actually figure out the small pieces, start putting it together, and start getting a better picture of what’s really going on,” says Shannon. “Chemistry was definitely challenging, but I loved how these small little pieces would come together and things would click.”

Motivated by her passion for chemistry and encouragement from her teachers, Shannon went on to earn her BS in chemistry from the University of Georgia, where she performed undergraduate research under the guidance of Dr. Ron Orlando. In Dr. Orlando’s lab, Shannon worked on creating a database of N-glycans for different species and designing a method for quantifying different IgG products. During this time, Shannon also had the opportunity to participate in Virginia Commonwealth University’s Summer Research Experience for Undergraduates where she spent 10 weeks in the lab of Dr. Julio Alvarez studying the use of glutathione as a source of green energy for new batteries.

In the fall of 2014, Shannon began her graduate studies in chemistry here at Emory. She joined the Weinert group, studying how the globin-coupled sensor protein family senses oxygen and transmits the binding signal into downstream events. “I work primarily with proteins from infectious bacteria. The idea behind my research is that if we can understand this one part of this very dangerous bug, then maybe we can create a new treatment method,” says Shannon. “I love working with the proteins I do because they are all heme proteins, so they are all red!”

Since joining the lab, Shannon has contributed to five publications, one as the primary author and two as co-first author. Her most recent publication is a book chapter in Advances in Microbial Physiology currently in press. “Shannon’s talent for research science, combined with her incredible drive, make it a true pleasure to work with her,” says Dr. Weinert. “Shannon’s fearlessness when it comes to trying new techniques has yielded results that have opened new insights into sensor globins and changed the way we think about how organisms sense and respond to oxygen.”

In addition to her scientific achievements, Shannon has also received several honors and awards during her time at Emory. She was awarded the Emory Graduate Diversity Fellowship for demonstrating outstanding academic achievement, the Outstanding Analytical Teacher’s Assistant Award for being the highest rated teacher’s assistant of the year, and the Carl Storm Underrepresented Minority Fellowship to attend the Gordon Research Conference.

Shannon is a member of the Pi Alpha Chemical Society (PACS), chemistry’s graduate student social and service organization. With PACS, she has had the chance to participate in outreach events and develop valuable relationships with her peers and coworkers. In addition, Shannon serves as communications chair and member of the Association for Women in Science at Emory (AWIS). With AWIS, she has participated in science demonstrations for young students at local schools and helped run a booth at the Atlanta Science Festival celebrating famous women scientists. Shannon is also on the board for the Chemistry Graduate School Prep Club, an organization designed to help prepare chemistry undergraduates from underrepresented backgrounds for future graduate studies. The prep club works primarily with students at institutions that aren’t currently associated with graduate programs to advise them on furthering their education by providing resources on research opportunities, applications, interviews, preparing for the GRE, and more.

After graduation, Shannon plans to go into industry research, where she is looking forward to leading her own projects.

Weinert Group in Nature Communications

Clip from the image RsbR haem pocket model and haem spectra." This image, and the article referenced, are licensed under a Creative Commons Attribution 4.0 International License.
Clip from the image RsbR haem pocket model and haem spectra.” This image, and the article referenced, are licensed under a Creative Commons Attribution 4.0 International License.

The Weinert Group has research featured in the June issue of Nature Communications. The paper, “An O2-sensing stressosome from a Gram-negative bacterium,” is co-authored by Xin Jia, Jian-bo Wang, Shannon Rivera, Duc Duong, and Emily E. Weinert.

Abstract:

Bacteria have evolved numerous pathways to sense and respond to changing environmental conditions, including, within Gram-positive bacteria, the stressosome complex that regulates transcription of general stress response genes. However, the signalling molecules recognized by Gram-positive stressosomes have yet to be identified, hindering our understanding of the signal transduction mechanism within the complex. Furthermore, an analogous pathway has yet to be described in Gram-negative bacteria. Here we characterize a putative stressosome from the Gram-negative bacterium Vibrio brasiliensis. The sensor protein RsbR binds haem and exhibits ligand-dependent control of the stressosome complex activity. Oxygen binding to the haem decreases activity, while ferrous RsbR results in increased activity, suggesting that the V. brasiliensis stressosome may be activated when the bacterium enters anaerobic growth conditions. The findings provide a model system for investigating ligand-dependent signalling within stressosome complexes, as well as insights into potential pathways controlled by oxygen-dependent signalling within Vibrio species.

[Full Article]