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USD 65 /hr

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Hire Dr. Waruna T.

United States

USD 65 /hr

Pharmacologist | in silico Drug Discovery | Molecular Dynamics (AMBER) | GPCR & Cell Biology | Scientific writing

Profile Summary

am a pharmacology and cell biology researcher specializing in receptor signaling, cellular assay development, and drug screening. I hold a PhD in Chemistry from Saint Louis University and currently work as a Postdoctoral Research Associate at Washington University School of Medicine, where my research focuses on G protein–coupled receptor (GPCR) pharmacology and opioid receptor signaling. My expertise centers on designing and implementing cell-based assays to study receptor activation, signaling pathways, and ligand pharmacology. I have extensive experience developing and optimizing assays to quantify receptor activity and downstream signaling events in mammalian cell systems. My work includes receptor signaling assays, functional drug screening, and quantitative analysis of cellular responses using fluorescence and luminescence-based biosensors. I routinely employ advanced imaging and cell biology techniques including confocal microscopy, fluorescence microscopy, and live-cell imaging to investigate receptor localization, signaling dynamics, and protein translocation in living cells. In addition, I have significant experience developing optogenetic tools to control protein signaling pathways with light, enabling precise spatiotemporal control of cellular signaling. Throughout my research career, I have collaborated with interdisciplinary teams in pharmacology, structural biology, and medicinal chemistry and have contributed to multiple peer-reviewed publications. My work integrates experimental pharmacology with quantitative data analysis to understand ligand activity, receptor signaling mechanisms, and drug responses in cellular systems. I can assist clients with: • Design and optimization of cell-based pharmacological assays • Drug screening using receptor signaling assays • Development of fluorescence or luminescence-based biosensor assays • Confocal microscopy and live-cell imaging analysis • Experimental strategies for studying GPCR signaling pathways • Optogenetic tool design and applications in cell signaling • Data analysis and visualization for cellular assay experiments • Scientific writing and manuscript editing I am committed to helping researchers and biotechnology teams develop robust experimental strategies and generate reliable data for drug discovery and cellular pharmacology studies.

Subject Matter Expertise

• ☆ Analytical Chemistry
• ☆ Computational Biology
• ☆ Biostatistics
• ☆ Biochemistry
• ☆ Biochemical Assays
• ☆ Structural Biology
• ☆ Molecular Biology
• ☆ PCR
• ☆ Molecular Cloning
• ☆ DNA Sequencing
• ☆ Mutagenesis
• ☆ Recombinant DNA
• ☆ Plasmid DNA
• ☆ Cell Biology
• ☆ Cell-Based Assays
• ☆ Cytochemistry
• ☆ Cell Signaling Pathways
• ☆ Membrane Biology
• ☆ Gene Regulation
• ☆ Biotechnology & Bioengineering
• ☆ Recombinant Protein Expression
• ☆ Microscopy
• ☆ Cryosectioning
• ☆ Light Microscopy
• ☆ Fluorescence Microscopy
• ☆ Data Analysis
• ☆ Image Processing
• ☆ Computer Simulation/Computational Modeling
• ☆ Predictive Modeling & Analytics
• ☆ Data Visualization
• ☆ Cell Culture
• ☆ Primary Cells
• ☆ Cell Line Engineering
• ☆ Cell Surface Receptors
• ☆ Synthetic Biology
• ☆ Biosensors
• ☆ Chemical Biology
• ☆ Biomolecular Engineering
• ☆ Gene Synthesis
• ☆ Genetic Engineering
• ☆ Gene Editing/CRISPR
• ☆ Protein/Enzyme Engineering
• ☆ Blotting
• ☆ Immunohistochemistry

Services

• Writing

Writing Medical Writing, Non-Medical Regulatory Writing, Creative Writing, General Proofreading & Editing

Work Experience

Postdoctoral research associate

Washington University in St. Louis

January 2026 - Present

Graduate Research Assistant

Saint Louis University

July 2022 - December 2025

Graduate Research Assistant

The University of Toledo Libraries

January 2021 - July 2022

Teaching Assistant

University of Colombo

March 2018 - February 2020

Education

PhD (Chemistry)

Saint Louis University

July 2022 - December 2025

Bachelor of Science (Chemistry and biochemistry)

University of Colombo

February 2014 - February 2018

Certifications

• Certification details not provided.

Publications

JOURNAL ARTICLE

AGS3-based optogenetic GDI induces GPCR-independent Gβγ signalling and macrophage migration @article{Thotamune_2025, title={AGS3-based optogenetic GDI induces GPCR-independent Gβγ signalling and macrophage migration}, volume={15}, ISSN={2046-2441}, url={http://dx.doi.org/10.1098/rsob.240181}, DOI={10.1098/rsob.240181}, number={2}, journal={Open Biology}, publisher={The Royal Society}, author={Thotamune, Waruna and Ubeysinghe, Sithurandi and Rajarathna, Chathuri and Kankanamge, Dinesh and Olupothage, Koshala and Chandu, Aditya and Copits, Bryan A. and Karunarathne, Ajith}, year={2025}, month=feb } . Open Biology.

Recombinant–Chemosynthetic Biosensors for Probing Cell Surface Signaling of Red Blood Cells and Other Cells @article{Ubeysinghe_2025, title={Recombinant–Chemosynthetic Biosensors for Probing Cell Surface Signaling of Red Blood Cells and Other Cells}, ISSN={2832-3637}, url={http://dx.doi.org/10.1021/cbmi.4c00067}, DOI={10.1021/cbmi.4c00067}, journal={Chemical & Biomedical Imaging}, publisher={American Chemical Society (ACS)}, author={Ubeysinghe, Sithurandi and Sebilleau, Chloe O. and Thotamune, Waruna and Rajarathna, Chathuri and Azibere, Samuel and Tennakoon, Mithila and Payton, John L. and Sprague, Randy S. and Martin, R. Scott and Sucheck, Steven J. and Karunarathne, Ajith}, year={2025}, month=jan } . Chemical & Biomedical Imaging.

In-silico predicted mouse melanopsins with blue spectral shifts deliver efficient subcellular signaling @article{Wijayaratna_2024, title={In-silico predicted mouse melanopsins with blue spectral shifts deliver efficient subcellular signaling}, volume={22}, ISSN={1478-811X}, url={http://dx.doi.org/10.1186/s12964-024-01753-0}, DOI={10.1186/s12964-024-01753-0}, number={1}, journal={Cell Communication and Signaling}, publisher={Springer Science and Business Media LLC}, author={Wijayaratna, Dhanushan and Sacchetta, Filippo and Pedraza-González, Laura and Fanelli, Francesca and Sugihara, Tomohiro and Koyanagi, Mitsumasa and Piyawardana, Senuri and Ghotra, Kiran and Thotamune, Waruna and Terakita, Akihisa and Olivucci, Massimo and Karunarathne, Ajith}, year={2024}, month=aug } . Cell Communication and Signaling.

Waruna Thotamune, Sithurandi Ubeysinghe, Kendra K. Shrestha, Mahmoud Elhusseiny Mostafa, Michael C. Young, Ajith Karunarathne (2024). Optical control of cell-surface and endomembrane-exclusive β-adrenergic receptor signaling . Journal of Biological Chemistry.

A new light on PLCβ! @article{Ubeysinghe_2024, title={A new light on PLCβ!}, volume={31}, ISSN={2451-9456}, url={http://dx.doi.org/10.1016/j.chembiol.2024.06.007}, DOI={10.1016/j.chembiol.2024.06.007}, number={7}, journal={Cell Chemical Biology}, publisher={Elsevier BV}, author={Ubeysinghe, Sithurandi and Thotamune, Waruna and Karunarathne, Ajith}, year={2024}, month=jul, pages={1236–1238} } . Cell Chemical Biology.

Abstract 1248 A photosensitive Isoproterenol (OptoIso) delivers spatiotemporally precise cell surface and endomembrane-exclusive beta-adrenergic receptor signaling @article{Thotamune_2024, title={Abstract 1248 A photosensitive Isoproterenol (OptoIso) delivers spatiotemporally precise cell surface and endomembrane-exclusive beta-adrenergic receptor signaling}, volume={300}, ISSN={0021-9258}, url={http://dx.doi.org/10.1016/j.jbc.2024.106734}, DOI={10.1016/j.jbc.2024.106734}, number={3}, journal={Journal of Biological Chemistry}, publisher={Elsevier BV}, author={Thotamune, Waruna and Ubeysinghe, Sithurandi and Shrestha, Kendra and Mostafa, Mahmoud and Edwards, Jim and Young, Michael and Karunarathne, Ajith}, year={2024}, month=mar, pages={106734} } . Journal of Biological Chemistry.

Spatiotemporal Optical Control of Gαq-PLCβ Interactions @article{Ubeysinghe_2023, title={Spatiotemporal Optical Control of Gαq-PLCβ Interactions}, volume={13}, ISSN={2161-5063}, url={http://dx.doi.org/10.1021/acssynbio.3c00490}, DOI={10.1021/acssynbio.3c00490}, number={1}, journal={ACS Synthetic Biology}, publisher={American Chemical Society (ACS)}, author={Ubeysinghe, Sithurandi and Kankanamge, Dinesh and Thotamune, Waruna and Wijayaratna, Dhanushan and Mohan, Thomas M. and Karunarathne, Ajith}, year={2023}, month=dec, pages={242–258} } . ACS Synthetic Biology.

CaaX-motif-adjacent residues influence G protein gamma (Gγ) prenylation under suboptimal conditions @article{Tennakoon_2023, title={CaaX-motif-adjacent residues influence G protein gamma (Gγ) prenylation under suboptimal conditions}, volume={299}, ISSN={0021-9258}, url={http://dx.doi.org/10.1016/j.jbc.2023.105269}, DOI={10.1016/j.jbc.2023.105269}, number={11}, journal={Journal of Biological Chemistry}, publisher={Elsevier BV}, author={Tennakoon, Mithila and Thotamune, Waruna and Payton, John L. and Karunarathne, Ajith}, year={2023}, month=nov, pages={105269} } . Journal of Biological Chemistry.

Selective C–H activation of unprotected allylamines by control of catalyst speciation @article{Landge_2023, title={Selective C–H activation of unprotected allylamines by control of catalyst speciation}, volume={3}, ISSN={2667-1093}, url={http://dx.doi.org/10.1016/j.checat.2023.100809}, DOI={10.1016/j.checat.2023.100809}, number={11}, journal={Chem Catalysis}, publisher={Elsevier BV}, author={Landge, Vinod G. and Mishra, Ankita and Thotamune, Waruna and Bonds, Audrey L. and Alahakoon, Indunil and Karunarathne, Ajith and Young, Michael C.}, year={2023}, month=nov, pages={100809} } . Chem Catalysis.

A novel UVA-labile β-adrenergic agonist allows for optical control of subcellular signaling @article{Thotamune_2023, title={A novel UVA-labile β-adrenergic agonist allows for optical control of subcellular signaling}, volume={385}, ISSN={0022-3565}, url={http://dx.doi.org/10.1124/jpet.122.563170}, DOI={10.1124/jpet.122.563170}, journal={The Journal of Pharmacology and Experimental Therapeutics}, publisher={Elsevier BV}, author={Thotamune, Waruna and Ubeysinghe, Sithurand and Karunarathne, Ajith and Shrestha, Kendra K. and Young, Michael C. and Tennakoon, Mithila}, year={2023}, month=jun, pages={87} } . The Journal of Pharmacology and Experimental Therapeutics.

Molecular regulation of G protein prenylation under sub-optimal conditions @article{Karunarathne_2023, title={Molecular regulation of G protein prenylation under sub-optimal conditions}, volume={385}, ISSN={0022-3565}, url={http://dx.doi.org/10.1124/jpet.122.558790}, DOI={10.1124/jpet.122.558790}, journal={The Journal of Pharmacology and Experimental Therapeutics}, publisher={Elsevier BV}, author={Karunarathne, Ajith and Tennakoon, Mithila and Thotamune, Waruna and Payton, John L.}, year={2023}, month=jun, pages={324} } . The Journal of Pharmacology and Experimental Therapeutics.

Toxic photochemistry and signaling repercussions of blue light in cells exposed to retinal @article{Karunarathne_2022, title={Toxic photochemistry and signaling repercussions of blue light in cells exposed to retinal}, volume={36}, ISSN={1530-6860}, url={http://dx.doi.org/10.1096/fasebj.2022.36.s1.0r485}, DOI={10.1096/fasebj.2022.36.s1.0r485}, number={S1}, journal={The FASEB Journal}, publisher={Wiley}, author={Karunarathne, Ajith and Thotamune, Waruna and Ratnayake, Kasun and Wong, Kwoon}, year={2022}, month=may } . The FASEB Journal.