Postdoctoral Symposium

John O’Brien, Ph.D.,
Department of Ophthalmology and Visual Science
Chair, Postdoctoral Symposium

Anja Karlstaedt, M.D., Ph.D.,
1st Place Winner, Dean’s Excellence Award for Postdoctoral Fellows
Internal Medicine, Division of Cardiology
“Cancer and the heart – Oncometabolic dysregulation of cardiac metabolism”

Dr. Anja Karlstaedt received her medical training and a PhD degree from the Charite Universitätsmedizin in Berlin, Germany.  During her thesis work with Drs. Vera Regitz-Zagrosek and Herman-Georg Holzhütter, Dr. Karlstaedt developed a genome-scale metabolic network of mammalian cardiac metabolism, CardioNet, and determined the computational impact of nutrients on ATP provision for the heart. After finishing her graduate training, Dr. Karlstaedt joined the laboratory of Dr. Heinrich Taegtmeyer, M.D., D.Phil., as a Postdoctoral Research Fellow at McGovern Medical School, where she discovered a novel link between cancer cell metabolism, and contractile dysfunction of the heart. Her studies exposed a connection between oncometabolite production in IDH-mutant tumors with metabolic alterations, specifically inhibition of the Krebs cycle enzyme α-Ketoglutarate dehydrogenase. This work was recently published in the Proceedings of the National Academy of Science U.S.A (PNAS), and proposes that specific metabolites produced by cancer cells impair cardiac metabolism. In other words: Tumor biology itself affects the heart. Dr. Karlstaedt received postdoctoral fellowship awards in succession, including, awards from the Friede-Springer Herz Stiftung (Berlin, Germany), the Roderick D. MacDonald Research Fund and the American Heart Association. Dr. Karlstaedt’s long term goal is to become an independent investigator in the field of molecular cardiology.

Sana Shaikh, Ph.D.,
2nd Place Winner, Dean’s Excellence Award for Postdoctoral Fellows
Department of Biochemistry and Molecular Biology
“AMPA Receptor Modulation by Auxiliary Proteins”

Sana Shaikh received her PhD in Biochemistry from The Ohio State University where she studied the regulation of the Sarcoplasmic Reticulum Calcium ATPase by the protein modulator Sarcolipin. She joined Dr. Vasanthi Jayaraman’s lab in the Department of Biochemistry and Molecular Biology as a postdoctoral research fellow in September 2015. Over the last two years Sana has been working on the modulation of AMPA receptors by auxiliary subunits such as stargazin using biophysical techniques. Sana’s research is critical to the glutamate receptor field as stargazin modulation of AMPA receptors is central to shaping AMPA receptor synaptic signaling which ultimately controls processes such as learning and memory. She used luminescence resonance energy transfer based measurements to model the structure of the stargazin-AMPA receptor complex to show the functional consequences mediated by stargazin on binding to AMPA receptors. She also used single molecule FRET to provide insight into the distribution of decoupled states in the AMPA receptor and to address the important question as to whether decoupling underlies desensitization. She showed that the AMPA receptor occupies varying degrees of all of the states reported so far, and more importantly each of these states are moved to more coupled states in the presence of stargazin. She has thus provided a mechanism by which stargazin modulates desensitization and laid the foundation of similar studies by other auxiliary proteins that could aid in the future development of target specific drug design. Her work on AMPA receptor modulation has secured her a travel award and also a two year Postdoctoral Fellowship from the American Heart Association.

Yongqiang Fan, Ph.D.,
3rd Place Winner, Dean’s Excellence Award for Postdoctoral Fellows
Department of Microbiology and Molecular Medicine
“Heterogeneity of Translational Errors in Single Bacterial Cells”

Yongqiang Fan received his PhD in Biochemistry from Dalian University of Technology, Dalian, China where he studied the unfolding and refolding behaviors of recombinant human brain-type creatine kinase under crowding systems. In 2013, Dr. Fan joined the laboratory of Dr. Jiqiang (Lanny) Ling in the Department of Microbiology and Molecular Genetics of McGovern Medical School as a postdoctoral fellow. Over the past four years, the main goal of Dr. Fan’s work is to understand regulation and the physiological roles of translational errors with combination of single-cell and population approaches. Gene expression noise at the transcription level is well defined, yet translational noise is poorly understood due to the lack of proper tools that separate it from transcriptional noise. To overcome this fundamental challenge, Dr. Fan developed a series of dual-fluorescence protein reporters that are transcribed into a single mRNA. They have successfully applied this system to determine the heterogeneity of stop codon read through in bacteria, and uncovered a regulatory mechanism of such heterogeneity. Intriguingly, they showed that individual cells with different levels of translational errors behave differently during recovery from stationary phase. In addition, Dr. Fan’s work also revealed that translation errors could protect bacteria cells from oxidative stresses by activating general stress response in advance, and make the cell more tolerant to antibiotic killing by decreasing the drug uptake. All of these works challenge the prevailing view that mis-translation is always detrimental, and provides mechanisms by which mis-translation benefits bacteria under stress conditions.