Use of split-dihydrofolate reductase for the detection of protein-protein interactions and simultaneous selection of multiple plasmids in Plasmodium falciparum

ABSTRACT First Person is a series of interviews with the first authors of a selection of papers published in Journal of Cell Science, helping early-career researchers promote themselves alongside their papers. Jia Yu and Pei-Ju Liao are co-first authors on ‘ Structural model of human PORCN illuminates disease-associated variants and drug-binding sites’, published in JCS. Jia is a senior postdoc in the lab of David Virshup at Duke-NUS Medical School, Singapore, investigating Wnt secretion and signalling; in particular, how Wnt trafficking and secretion is regulated by two integral membrane proteins, porcupine and WLS. Pei-Ju is a research assistant in the same lab, investigating protein–protein interactions in the systems biology of signalling pathways using protein structure modelling and protein complex simulation.

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In vitro activities of novel antifolate drug combinations against Plasmodium falciparum and human granulocyte CFUs.

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.39.4.948 ◽

1995 ◽

Vol 39 (4) ◽

pp. 948-952 ◽

Cited By ~ 34

Author(s):

P A Winstanley ◽

E K Mberu ◽

I S Szwandt ◽

A M Breckenridge ◽

W M Watkins

Keyword(s):

Plasmodium Falciparum ◽

Dihydrofolate Reductase ◽

Bone Marrow Cells ◽

Rank Order ◽

Drug Combinations ◽

Reductase Inhibitors ◽

Potent Drug ◽

Dihydrofolate Reductase Inhibitors ◽

Selection Of

The potency of antimalarial dihydrofolate reductase inhibitors, alone and in synergistic combination with dihydropteroate synthetase inhibitors, against the Kenyan K39 strain of Plasmodium falciparum (pyrimethamine resistant) and against normal replicating human bone marrow cells in in vitro culture has been studied. Therapeutic indices and rank order of synergistic potency were derived. Trimethoprim, pyrimethamine, and the quinazolines WR159412 and WR158122 had the smallest therapeutic indices (1.39, 4.38, 2.56, and 90.0, respectively), while the three triazines clociguanil, WR99210, and chlorcycloguanil had the largest (3,562, 3,000, and 2,000, respectively). In rank order of decreasing activity against P. falciparum, the six most potent drug combinations were WR99210-dapsone, chlorcycloguanil-dapsone, WR158122-dapsone, WR159412-dapsone, WR159412-sulfamethoxazole, and chlorcycloguanil-sulfamethoxazole; pyrimethamine-sulfadoxine was the least potent combination. These experiments form a basis for the selection of rapidly eliminated antifolate combinations for further clinical testing.

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Pseudokinase drug intervention: a potentially poisoned chalice

Biochemical Society Transactions ◽

10.1042/bst20130078 ◽

2013 ◽

Vol 41 (4) ◽

pp. 1083-1088 ◽

Cited By ~ 10

Author(s):

Jeroen Claus ◽

Angus J.M. Cameron ◽

Peter J. Parker

Keyword(s):

Protein Interactions ◽

Drug Targets ◽

Binding Pocket ◽

Atp Binding ◽

Potential Drug ◽

Protein Protein Interactions ◽

Drug Intervention ◽

Potential Impact ◽

Potential Drug Targets ◽

Selection Of

Pseudokinases, the catalytically impaired component of the kinome, have recently been found to share more properties with active kinases than previously thought. In many pseudokinases, ATP binding and even some activity is preserved, highlighting these proteins as potential drug targets. In both active kinases and pseudokinases, binding of ATP or drugs in the nucleotide-binding pocket can stabilize specific conformations required for activity and protein–protein interactions. We discuss the implications of locking particular conformations in a selection of (pseudo)kinases and the dual potential impact on the druggability of these proteins.

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The cytoplasmic domain of the Plasmodium falciparum ligand EBA-175 is essential for invasion but not protein trafficking

The Journal of Cell Biology ◽

10.1083/jcb.200301046 ◽

2003 ◽

Vol 162 (2) ◽

pp. 317-327 ◽

Cited By ~ 64

Author(s):

Tim-Wolf Gilberger ◽

Jennifer K. Thompson ◽

Michael B. Reed ◽

Robert T. Good ◽

Alan F. Cowman

Keyword(s):

Plasmodium Falciparum ◽

Host Cell ◽

Protein Interactions ◽

Protein Trafficking ◽

Cytoplasmic Domain ◽

Specific Protein ◽

Host Cells ◽

Protein Protein Interactions ◽

Parasite Plasmodium Falciparum ◽

Erythrocyte Binding

The invasion of host cells by the malaria parasite Plasmodium falciparum requires specific protein–protein interactions between parasite and host receptors and an intracellular translocation machinery to power the process. The transmembrane erythrocyte binding protein-175 (EBA-175) and thrombospondin-related anonymous protein (TRAP) play central roles in this process. EBA-175 binds to glycophorin A on human erythrocytes during the invasion process, linking the parasite to the surface of the host cell. In this report, we show that the cytoplasmic domain of EBA-175 encodes crucial information for its role in merozoite invasion, and that trafficking of this protein is independent of this domain. Further, we show that the cytoplasmic domain of TRAP, a protein that is not expressed in merozoites but is essential for invasion of liver cells by the sporozoite stage, can substitute for the cytoplasmic domain of EBA-175. These results show that the parasite uses the same components of its cellular machinery for invasion regardless of the host cell type and invasive form.

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