Possible Rotation Projects:
In vitro assay development for drug discovery
Developing new cell-based imaging methods for protein:protein interactions
Evolutionary biology of cancer and antiviral drug resistance
Training Technologies Used:
- Recombinant protein expression and purification
- Surface plasmon resonance
- Biophysics and structural biology
- Cell-based imaging assays
- HIV assays
- High-throughput screening
- Kinase assays
- Chemical biology
- Animal models of cancer and HIV
- Ph.D. in Pharmacology from University of Pennsylvania
- B.A. in Biochemistry from University of Pennsylvania
Gonzalez-Areizaga G, Shu ST, Alvarado JJ, Shi H, Chen L, Smithgall TE. Constraining regulatory domain dynamics of the Src kinase Fgr increases ATP-site inhibitor sensitivity and impairs bone marrow engraftment. Cell Reports 45: 117551, 2026.
Selzer AM, Gerlach G, Gonzalez-Areizaga G, Wales TE, Cui SY, Iyer P, Engen JR, Camacho C, Ishima R, Smithgall TE. An SH3-binding allosteric modulator stabilizes the global conformation of the AML-associated Src-family kinase, Hck. J. Biol. Chem. 301:108088, 2025.
Shu ST, Chen L, Gonzalez-Areizaga G, Smithgall TE. Constitutive activation of the Src-family kinases Fgr and Hck enhances the tumor burden of acute myeloid leukemia cells in immunocompromised mice. Sci. Rep. 15: 174, 2025.
Emert-Sedlak LA, Tice CM, Shi H, Alvarado JJ, Shu ST, Reitz AB, Smithgall TE. PROTAC-mediated degradation of HIV-1 Nef efficiently restores cell-surface CD4 and MHC-I expression and blocks HIV-1 replication. Cell Chem. Biol. 31: 658-668, 2024.
Aryal M, Lin D, Regan K, Du S, Shi H, Alvarado JJ, Ilina TV, Andreotti AH, Smithgall TE. HIV-1 Nef Activates the Tec-Family Kinase Btk by Stabilizing Intermolecular SH3-SH2 Domain Interaction. Science Signaling, 15(752): eabn8359, 2022.
Du S, Alvarado, JJ, Wales TE, Moroco JA, Engen JR, Smithgall TE. ATP-site Inhibitors Induce Unique Conformations of the Acute Myeloid Leukemia-Associated Src-family Kinase, Fgr. Structure (Cell Press) 30: 1508-1517, 2022.
Li WF, Aryal M, Shu ST, Smithgall TE HIV-1 Nef dimers short-circuit immune receptor signaling by activating Tec-family kinases at the host cell membrane. J. Biol. Chem. 295: 5163–5174, 2020
Patel RK, Patel YK, Smithgall TE In Vitro Evolution Reveals a Single Mutation as Sole Source of Src-Family Kinase C-Helix-out Inhibitor Resistance. ACS Chem. Biol. 15: 2175–2184, 2020.
Staudt RP, Smithgall TE Nef homodimers down-regulate SERINC5 by AP-2-mediated endocytosis to promote HIV-1 infectivity. J. Biol. Chem. 295: 15540-15552, 2020.
Shen, K, Moroco JA, Patel RK, Shi H, Engen JR, Dorman HR, Smithgall, T.E. The Src-family kinase Fgr is a transforming oncoprotein independent of SH3-SH2 domain regulation. Science Signaling 11: eaat5916, 2018.
HIV-1 accessory proteins as new drug targets for AIDS. Treatment for HIV disease was revolutionized in the mid-1990’s with the advent of antiretroviral drugs, which inhibit viral enzymes as well as fusion of the virus to the host cell. Unfortunately, existing antiretroviral therapy does not clear the virus from the body, requiring life-long drug administration to prevent relapse. The cumulative toxic effects of antiretroviral drug exposure over decades may cause clinical metabolic disturbances and organ damage. Chronic therapy also promotes drug resistance, ultimately limiting drug utility. To address these issues, we are developing several classes of compounds that interfere with the functions of HIV-1 Nef, one of four viral accessory factors essential for HIV pathogenesis. Nef, a small membrane-associated protein unique to primate lentiviruses, is critical for HIV-1 replication in vivo, immune escape of HIV-infected cells, and AIDS progression. Using our patented screening assays, we have identified HIV Nef inhibitors with potent antiretroviral activity against Nef-dependent HIV replication. Nef antagonists have the potential to synergize with current antiretroviral drugs, thereby lowering current doses and their associated toxicities and reducing the risk of drug resistance. Therapeutic inhibition of Nef may also restore recognition of HIV-infected cells by the patient’s own immune system, potentially eradicating the virus.
Discovery of small molecule allosteric inhibitors of non-receptor tyrosine kinases. In theory, inhibition of undesirable enzymatic activity responsible for disease can be accomplished either directly at the active site or indirectly at a distance (allostery). Important examples of selective enzyme inhibition come from the field of protein-tyrosine kinases, an emerging therapeutic target class for cancer and infectious diseases. Virtually all clinically useful kinase inhibitors to date compete for ATP binding at the kinase domain active site. However, the high degree of protein kinase sequence and structural homology limits the development of highly selective ATP-competitive kinase inhibitors. Alternative drug discovery avenues include allosteric inhibitors that target structural features outside of the kinase domain active site that are unique to individual kinase subfamilies. Allosteric inhibitor mechanisms are likely to exhibit greater specificity for their intended kinase targets, and may also stabilize kinase domain conformations that promote the action of existing inhibitors targeting the active site. Based on these principles, we are actively engaged in a drug discovery campaign to find small molecules that enhance the natural allosteric mechanisms associated with kinase domain regulation. We have developed chemical library screening approaches based on this concept for the identification of selective inhibitors for protein-tyrosine kinases of the non-receptor class, including members of the Src, Fes/Fps and Abl kinase families. Allosteric inhibitors of these kinases are anticipate to have utility in the treatment of cancer and infectious diseases.
