Rate My Professor Ajith Karunarathne

Ajith Karunarathne, Ph.D., serves as an Associate Professor in the Department of Chemistry at Saint Louis University, a position he assumed in summer 2022 upon relocating his research group from the University of Toledo, where he held a tenured faculty position. He earned his B.S. from the University of Sri Jayewardenepura, Sri Lanka, Ph.D. in Biological Chemistry from Michigan State University under the advisement of Prof. Dana Spence, and completed postdoctoral training in signal transduction and optogenetics at Washington University School of Medicine with Professor N. Gautam.

Karunarathne specializes in biological chemistry, chemical biology, and molecular pharmacology, applying a reductionist approach to dissect biological processes at the subcellular level and engineer molecular tools to reveal disease mechanisms. His laboratory integrates cellular signaling with single-cell and subcellular optogenetics to probe cell communication and behavior, develops novel optogenetic tools such as opsin-based systems optimized for in vivo applications and phototropin- and cryptochrome-based regulators of G protein signaling independent of GPCRs, examines mechanisms of signaling pathways governing cell migration, invasion, and proliferation, explores strategies to hijack insulin receptor signaling for glucose uptake control, investigates the phototoxic effects of retinal under blue light exposure using computational and hybrid chemical-cellular methods, and engineers photopharmacology tools for light-activated modulation at precise subcellular locations. Representative publications include "G protein gamma subunit, a hidden master regulator of cellular signaling" (J. Biol. Chem., 2022), "Blue light excited retinal intercepts cellular signaling" (Sci. Rep., 2018; Altmetric top 100 global publication), "A short C-terminal peptide in Gγ regulates Gβγ signaling efficacy" (Mol. Biol. Cell, 2021), "Dissociation of the G protein βγ from the Gq-PLCβ complex partially attenuates PIP2 hydrolysis" (J. Biol. Chem., 2021), and "Molecular regulation of PLCβ signaling" (2023). He received the Excellence in Research Award from the College of Natural Sciences and Mathematics in 2019 and serves as an Editorial Board Member for the Journal of Biological Chemistry and PLOS One.