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!

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.


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]