Professional Education

  • Bachelor of Science, Michigan State University (2011)
  • Doctor of Philosophy, University of Michigan Ann Arbor (2017)

Stanford Advisors


All Publications

  • Selective Proteolysis to Study the Global Conformation and Regulatory Mechanisms of c-Src Kinase. ACS chemical biology Agius, M. P., Ko, K. S., Johnson, T. K., Kwarcinski, F. E., Phadke, S., Lachacz, E. J., Soellner, M. B. 2019


    Protein kinase pathways are traditionally mapped by monitoring downstream phosphorylation. Meanwhile, the noncatalytic functions of protein kinases remain under-appreciated as critical components of kinase signaling. c-Src is a protein kinase known to have noncatalytic signaling function important in healthy and disease cell signaling. Large conformational changes in the regulatory domains regulate c-Src's noncatalytic functions. Herein, we demonstrate that changes in the global conformation of c-Src can be monitored using a selective proteolysis methodology. Further, we use this methodology to investigate changes in the global conformation of several clinical and nonclinical mutations of c-Src. Significantly, we identify a novel activating mutation observed clinically, W121R, that can escape down-regulation mechanisms. Our methodology can be expanded to monitor the global conformation of other tyrosine kinases, including c-Abl, and represents an important tool toward the elucidation of the noncatalytic functions of protein kinases.

    View details for DOI 10.1021/acschembio.9b00306

    View details for PubMedID 31287657

  • UM-9107: A selective wild-type and T315I Bcr-Abl inhibitor with in vivo activity against chronic myelogenous leukemia Phadke, S., Lopez-Barcons, L., Johnson, T. K., Lachacz, E. J., Merajver, S. D., Soellner, M. B. AMER ASSOC CANCER RESEARCH. 2019
  • Bivalent Inhibitors of c-Src Tyrosine Kinase That Bind a Regulatory Domain BIOCONJUGATE CHEMISTRY Johnson, T. K., Soellner, M. B. 2016; 27 (7): 1745-1749


    We have developed a general methodology to produce bivalent kinase inhibitors for c-Src that interact with the SH2 and ATP binding pockets. Our approach led to a highly selective bivalent inhibitor of c-Src. We demonstrate impressive selectivity for c-Src over homologous kinases. Exploration of the unexpected high level of selectivity yielded insight into the inherent flexibility of homologous kinases. Finally, we demonstrate that our methodology is modular and both the ATP-competitive fragment and conjugation chemistry can be swapped.

    View details for DOI 10.1021/acs.bioconjchem.6b00243

    View details for Web of Science ID 000380298900024

    View details for PubMedID 27266260

  • Conformation-Selective Analogues of Dasatinib Reveal Insight into Kinase Inhibitor Binding and Selectivity ACS CHEMICAL BIOLOGY Kwarcinski, F. E., Brandvold, K. R., Phadke, S., Beleh, O. M., Johnson, T. K., Meagher, J. L., Seeliger, M. A., Stuckey, J. A., Soellner, M. B. 2016; 11 (5): 1296-1304


    In the kinase field, there are many widely held tenets about conformation-selective inhibitors that have yet to be validated using controlled experiments. We have designed, synthesized, and characterized a series of kinase inhibitor analogues of dasatinib, an FDA-approved kinase inhibitor that binds the active conformation. This inhibitor series includes two Type II inhibitors that bind the DFG-out inactive conformation and two inhibitors that bind the αC-helix-out inactive conformation. Using this series of compounds, we analyze the impact that conformation-selective inhibitors have on target binding and kinome-wide selectivity.

    View details for DOI 10.1021/acschembio.5b01018

    View details for Web of Science ID 000376473600017

    View details for PubMedID 26895387

  • Ordering a Dynamic Protein Via a Small-Molecule Stabilizer JOURNAL OF THE AMERICAN CHEMICAL SOCIETY Wang, N., Majmudar, C. Y., Pomerantz, W. C., Gagnon, J. K., Sadowsky, J. D., Meagher, J. L., Johnson, T. K., Stuckey, J. A., Brooks, C. L., Wells, J. A., Mapp, A. K. 2013; 135 (9): 3363-3366


    Like many coactivators, the GACKIX domain of the master coactivator CBP/p300 recognizes transcriptional activators of diverse sequence composition via dynamic binding surfaces. The conformational dynamics of GACKIX that underlie its function also render it especially challenging for structural characterization. We have found that the ligand discovery strategy of Tethering is an effective method for identifying small-molecule fragments that stabilize the GACKIX domain, enabling for the first time the crystallographic characterization of this important motif. The 2.0 Å resolution structure of GACKIX complexed to a small molecule was further analyzed by molecular dynamics simulations, which revealed the importance of specific side-chain motions that remodel the activator binding site in order to accommodate binding partners of distinct sequence and size. More broadly, these results suggest that Tethering can be a powerful strategy for identifying small-molecule stabilizers of conformationally malleable proteins, thus facilitating their structural characterization and accelerating the discovery of small-molecule modulators.

    View details for DOI 10.1021/ja3122334

    View details for Web of Science ID 000315936700016

    View details for PubMedID 23384013

    View details for PubMedCentralID PMC3607081

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