1. Academic Validation
  2. Plasmodium PK9 Inhibitors Promote Growth of Liver-Stage Parasites

Plasmodium PK9 Inhibitors Promote Growth of Liver-Stage Parasites

  • Cell Chem Biol. 2019 Mar 21;26(3):411-419.e7. doi: 10.1016/j.chembiol.2018.11.003.
Rene Raphemot 1 Amber Leigh Eubanks 1 Maria Toro-Moreno 1 Rechel Anne Geiger 1 Philip Floyd Hughes 2 Kuan-Yi Lu 3 Timothy Arthur James Haystead 2 Emily Rose Derbyshire 4
Affiliations

Affiliations

  • 1 Department of Chemistry, Duke University, 124 Science Drive, Durham, NC 27708, USA.
  • 2 Department of Pharmacology and Cancer Biology, Duke University Medical Center, 308 Research Drive, Durham, NC 27710, USA.
  • 3 Department of Molecular Genetics and Microbiology, Duke University Medical Center, 213 Research Drive, Durham, NC 27710, USA.
  • 4 Department of Chemistry, Duke University, 124 Science Drive, Durham, NC 27708, USA; Department of Molecular Genetics and Microbiology, Duke University Medical Center, 213 Research Drive, Durham, NC 27710, USA. Electronic address: emily.derbyshire@duke.edu.
Abstract

There is a scarcity of pharmacological tools to interrogate protein kinase function in Plasmodium parasites, the causative agent of malaria. Among Plasmodium's protein kinases, those characterized as atypical represent attractive drug targets as they lack sequence similarity to human proteins. Here, we describe takinib as a small molecule to bind the atypical P. falciparum protein kinase 9 (PfPK9). PfPK9 phosphorylates the Plasmodium E2 ubiquitin-conjugating Enzyme PfUBC13, which mediates K63-linkage-specific polyubiquitination. Takinib is a potent human TAK1 inhibitor, thus we developed the Plasmodium-selective takinib analog HS220. We demonstrate that takinib and HS220 decrease K63-linked ubiquitination in P. falciparum, suggesting PfPK9 inhibition in cells. Takinib and HS220 induce a unique phenotype where Parasite size in hepatocytes increases, yet high compound concentrations decrease the number of parasites. Our studies highlight the role of PK9 in regulating Parasite development and the potential of targeting Plasmodium kinases for malaria control.

Keywords

PK9; Plasmodium; atypical kinase; high-throughput screen; kinase; malaria.

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