It is with sadness that the Department announces that our former colleague Dr. Erica Johnson passed away on March 21, 2026 after a long battle with cancer. Erica was a brilliant scientist. She received her BA summa cum laude from Vanderbilt University and her PhD under the mentorship of Alexander Varshavsky from the Massachusetts Institute of Technology. Her postdoctoral training was with Gunter Blobel at the Rockefeller University. She was recruited as an Assistant Professor to the Department of Biochemistry and Molecular Biology at Jefferson in 1999 and was promoted to Associate Professor in 2008. In 2014 she took a position as Program Manager in the Genomic Pathology Program at Thomas Jefferson University Hospital. She retired in 2020 and traveled with family and friends while maintaining her residence within walking distance of the Jefferson campus. Erica maintained an active interest in science throughout her life. She collaborated with the Winter laboratory as recently as 2024.
Erica was a talented experimentalist who thought deeply about science. While in the Varshavsky laboratory she published important papers that contributed to our understanding of how the attachment of ubiquitin to specific proteins targets those proteins for degradation. In the Blobel laboratory she turned her attention to the ubiquitin-like protein, SUMO. She identified the enzymes that activate SUMO for conjugation, the SUMO conjugating enzyme, and proteins that confer specificity to SUMO attachment. As an independent investigator at Jefferson, she went on to identify multiple substrate proteins that are attached to SUMO and identified an isopeptidase that removes SUMO from these substrates. She identified mechanisms that connect SUMO conjugation to DNA repair pathways and homologous recombination. She published in top-tier journals. Her laboratory was funded by the National Science Foundation, the W.W. Smith Charitable Trust, and the National Institutes of Health. She was a talented educator who taught medical, pharmacy, as well as PhD and MS students. Her lectures were received enthusiastically, and she was known for clarity as well as an uncanny ability to focus her presentations on important and broadly relevant concepts. She was a valued mentor to postdoctoral, PhD and MS trainees. Erica was not only a brilliant scientist; she was kind and compassionate while also being honest and direct. She was a valued friend and colleague and will be missed.