Faculty
CELLULAR PHOTOCHEMISTRY LABORATORY
Ajith Karunarathne, PhD
Assistant Professor
Email: ajith.karunarathne@utoledo.edu
Office: BO 2098 A/B
Phone: (419) 530-7880
Fax: (419) 530-4033
Professional Background:
B.S.: University of Sri Jayewardenepura, Sri Lanka
PhD.: Michigan State University, East Lansing, Michigan, USA
Postdoctoral: Washington University School of Medicine, St. Louis, Missouri, USA
Research
Group Web Page and Twitter feed
Publications
NEWS
Our research named a Top 100 science paper of 2018
Kasun Ratnayake, Ph.D. graduate student in the CELLPHOTOCHEM lab, received the award for the best oral presentation by a student at the 2018 ANACHEM Symposium on November 1 for his talk Blue Light-Sensitized Retinal Disrupts Cellular Signaling. Nice Job Kasu
Our LATEST collaborative RESEARCH ARTICLE ON decoding calcium oscillations in neurons is just accepted at ACS Chemical Neuroscience. part of the work was performed @CHEMISTRYTOLEDO IN @UTOLEDO. CONGRATULATIONS TO AUTHORS!
Swain, S., Gupta, R. K., Ratnayake, K., Priyanka, P., Singh, R., Jana, S., Mitra, K., Karunarathne, A., Giri, L., (2018). Confocal imaging and k-means clustering of GABAB and mGluR mediated modulation of Ca2+ spiking in hippocampal neurons. ACS Chemical Neuroscience.
The latest research article on mechanisms of Blue light induced cellular toxicity from my research group at @ChemistryToledo in @UToledo. CONGRATULATIONS TO AUTHORS!
Ratnayake, K., Payton, J. L., Lakmal, O. H., and Karunarathne, A. (2018) Blue light excited retinal intercepts cellular signaling. Scientific Reports 8, 10207 https://www.nature.com/articles/s41598-018-28254-8
OUR RESEARCH SHEDS A NEW LIGHT ON GPCR REGULATION BY G PROTEINS. CONGRATULATIONS TO AUTHORS!
Samaradivakara, S., Kankanamge, D., Senarath, K., Ratnayake, K., and Karunarathne, A. (2018) G protein gamma (Ggamma ) subtype dependent targeting of GRK2 to M3 receptor by Gbetagamma. Biochemical Biophysical Research Communications, 2018 Jun 11. pii: S0006-291X(18)31295-6.
Two latest publications from our group just appeared online. Congratulations to authors!
Kankanamge, D., Ratnayake, K., Samaradivakara, S., and Karunarathne, A. (2018). Melanopsin (Opn4) employs Gαi and Gβγ as major signal transducers. Journal of Cell Science.
Senarath, K.; Kankanamge, D.; Samaradivakara, S.; Ratnayake, K.; Tennakoon, M.; Karunarathne,
A. (2018). Regulation of G Protein βγ Signaling. International Review of Cell and Molecular Biology.
OUR RECENT JBC PAPER IS AMONG ONE OF THE MOST VIEWED ARTICLES. CONGRATULATIONS TO AUTHORS!
Senarath, K., Payton, J. L., Kankanamge, D., Siripurapu, P., Tennakoon, M., and Karunarathne, A. (2018) Gγ identity dictates efficacy of Gβγ signaling and macrophage migration. Journal of Biological Chemistry 2018; 293(8):2974-2989.
Year 2017 publications from our lab:
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Siripurapu, P.; Kankanamge, D.; Ratnayake, K.; Senarath, K.; Karunarathne, A. J Biol Chem 2017, 292, 17482-17495.
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Ratnayake, K.; Kankanamge, D.; Senarath, K.; Siripurapu, P.; Weis, N.; Tennakoon, M.; Payton, J. L.; Karunarathne, A. Methods in cell biology 2017, 142, 1-25.
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Gupta, R. K.; Swain, S.; Kankanamge, D.; Priyanka, P. D.; Singh, R.; Mitra, K.; Karunarathne, A.; Giri, L. SLAS discovery 2017, 2472555217693378.
Our findings on itch sensation are now published in the journal SCIENCE SIGNALING. Click here to read it. Click here to read the UT news article on this research.
Our review article Titled " Subcellular optogenetics: controlling signaling and single cell behavior" is published in JOURNAL OF CELL SCIENCES. Click here to read the article.
Our findings are published in the journal NEURON on cross-talks between Serotonin (5HT)- gastrin-releasing peptide (GRP) receptors and subsequent effects on itch sensation. This new is on NBC news national coverage.
Click here watch NBC Brian Williams talking about this work.
Click here to read this article.
Exciting undergraduate and graduate research opportunities!
We offer a science outreach program for high school students to conduct research in life sciences!
Please contact Dr. Ajith Karunarathne for more information.
Research Interests:
Bioanalytical, Optical chemistry and Optogenetics, Molecular Imaging, and Signal Transduction
1. GPCR and G protein signaling in immune and cancer cell migration.
2. Engineering optogenetic approaches to control subcellular signaling.
3. Engineering of biosensors and assay to quantify dynamic behaviors of signaling
molecules.
4. Experiment-guided mathematical-computations modeling of cellular signaling networks.
5. Functional characterization opsin for their ability to control mammalian cell signaling.
6. Optical isomerization of push-pull molecules and the applicability in biomedical
research.
Research Synopsis:


HeLa cell in the movie expresses G protein-coupled vision receptors (Opsins) from the retina of the eye. The cell also expresses mCherry tagged gamma-9 subunit. On GPCR activation, G protein beta-gamma subunits translocate to the internal membranes. In this experiment, opsins in the left side of the cell are exposed to a confined blue light pulse (red box). Please note the disappearance of mCherry-gamma-9 from the exposed plasma membrane region immediately after the pulse and appearance in the adjacent ER. Opsin activation is transient and therefore, mCherry-gamma-9 returned to the plasma membrane towards the end of the movie. This shows that opsin can be used to spatially and temporally control signaling in subcellular regions in a cell(Subcellular optogenetics). The plot shows the dynamics of mCherry-gamma9 in adjacent internal membranes. Karunarathne et al, 2013, PNAS – E1565-E1574