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Structural Parasitology

Group Site: 
toronto
Group Leader: 

Raymond Hui

Group Info

Research Areas

The Structural Parasitology group works on structural biology of proteins from malaria pathogens as well as other protozoan parasites. Specifically, we have expressed proteins and obtained structures from 5 Plasmodium species, Cryptosporidium parvum and Toxoplasma gondii, as well as Trypanosoma and Leishmania.  In total, our group has deposited ~40% of all apicomplexan and kinetoplastid structures in the Protein Data Bank (PDB).

So far, our structures span protein families such as cyclophilins, kinases and proteases as well as pathways for biosynthesis, salvage and metabolism of isoprenoids, fatty acids, phospholipids, pyrimidines, purines and polyamines. In each instance, we collaborate with other labs and attempt to use structures to understand the molecular mechanism of enzymatic action and the interaction between a protein and its inhibitors.  We also aim to identify chemical probes which may be used to characterize potential anti-parasitic drug targets.

Protein kinases

There are three unique sub-families of protein kinases amongst apicomplexan parasites: rhoptry kinases which are found only in Toxoplasma, FIKK kinases an calcium-dependent protein kinases (CDPK) which are also found in a small number of plant species.  In collaboration with L. David Sibley at the University of Washington in St. Louis, our group solved the first rhoptry kinase structures (ROP2A and ROP8), enabling us to propose a hypothesis for their mechanism of activation [Qiu et al, EMBO, 2008].  We also solved the first ever structures of CDPKs (from plants or parasites) with both the kinase domain and the calcium-binding domain intact.  Working with Sebastian Lourido and David Sibley, we used these structures to discover that the activation mechanism of CDPKs involved a dramatic refolding and movement of the calcium domain [Wernimont et al, Nature Struct. & Mol. Biology, 2010; Wernimont et al, Proteins, 2011], and also to identify specific chemical probes used to support genetic findings about function of TgCDPK1 [Lourido et al, Nature, 2010].

Heat shock proteins

Hsp90 is an important drug target for cancer and other diseases.  It is also an important chaperone in protozoan parasites.  We have solved the structures of of a number of Hsp90 and Hsp90-like proteins from Plasmodium, Trypanosoma and Leishmania, including the N-terminal ATPase domain, the middle domain and the C-terminal domain.  We have also screened these chaperones against a focused panel of known inhibitors human Hsp90.  Combined with our structures, the screening data is enabling us to identify potential chemical selectivity cues that can be used for structure-guided design of selective anti-parasitic drug candidates.

Isoprenoid biosynthesis, nucleotide metabolism and other pathways

In addition to protein families such as protein kinases and Hsp's, we also study various enzymatic pathways.  For example, in collaboration with James Dunford and Udo Oppermann at the University of Oxford, as well as Michael Arrowood at CDC and Eric Oldfield at U. of Illinois at Urbana Champain, we investigated the functions and structures of the C. parvum and P. vivax homologues of farnesyl pyrophosphate synthase, and found both parasite enzymes to produce different products from the human enzyme.  The structures aided us in formulating an explanation for this mechanistic disparity, and also revealed how each enzyme interacted differently with bisphosphonates [Artz et al, Chem. Biol., 2008; Artz et al, JBC, 2011]. 

Our work on pyrmidine de novo synthesis and other pathways is also leading not only to structures, but also functional implications and characterization of interaction between the enzymes and their inhibitors.

Group Members
Raymond Hui Ph.D.

Ray is a proud father and photographer, and holds a black belt in karate.   Structural biology serves to channel his fascination with geometry and imaging.  He aims to contribute to parasitology by conducting research at the intersection of science and engineering. 

Exemplifying his embrace of challenges, Ray remains a diehard fan of the Toronto Maple Leafs. 

Tariq Massad Ph.D.

Tariq has a background in NMR spectroscopy and crystallography.  He completed his doctoral research at the Stockholm University and joined the Structural Parasitology group at SGC in 2010.  When not purifying and crystallizing parasite proteins, Tariq finds happiness with his wife and children.

don't worry - not truly a lazy eye
Amy Wernimont Ph.D.

Amy obtained her PhD in biochemistry from Northwestern University in 2003.  From there, she pursued post-doctoral research at the EMBL in Grenoble France, studying HIV-associated proteins and solved the structure of the rabies virus nuclear protein N.  Amy then joined SGC as one of the crystallographers responsible for solving many different protein structures under a strict timeline, all immediately freely available to the public.  As the crystallagrapher for the Structural Parasitology group, Amy has deposited more than 100 parasite protein structures into the pdb, and has been team lead for the group's research in protein kinases.

She has taken on increased responsibilies within the SGC network and these include project management, manuscript and grant writing, networking and partnerships.  Her interests include global health research and development, and all things outdoors.

Linda Lin
Linda received her M.Sc. degree in Life Science from National Central University, Taiwan. Then she worked for Chang Gung Medical Foundation as a research associate, focusing on improving diagnostic accuracy and efficiency for hepatitis B virus. Later on, she worked as a medical writer until she joined SGC in 2006.
 
Linda is highly experienced in expression, purification and crystallization of parasite proteins.  In particular, she has crystallized a number of protein kinases, the structures of which led to the elucidation of their mechanism of action. When not wearing a labcoat, she loves to work in the kitchen with her apron on.
Khan Osman

Khan is a doctoral student who is interested in FIKK kinases.  He completed his M.Sc. in biochemistry at the University of Saskatchewan.  In his spare time, Khan enjoys playing field hockey and photography.

Structures

Protein kinase structures solved by the Structural Parasitology group at SGC:

Heat shock protein structures solved by the Structural Parasitology group at SGC:


Publications

Sample publications:

Brokx SJ, Wernimont AK, Dong A, Wasney GA, Lin YH, Lew J, VedadiM, Lee WH and Hui R. Characterization of 14-3-3 proteins from Cryptosporidium parvum. PLoS One. 2011; 6(8). PMID: 21853016

Hills T, Srivastava A, Ayi K, Wernimont AK, Kain K, Waters AP, Hui R and Pizarro JC. Characterization of a new phosphatase from Plasmodium. PLoS One. 2011 Oct; 179(2):69-79. PMID: 21689687

Mariño K, Güther ML, Wernimont AK, Qiu W, Hui R, Ferguson MA. Characterization, localization, essentiality, and high-resolution crystal structure of glucosamine 6-phosphate N-acetyltransferase from Trypanosoma brucei. Eukaryot Cell. 2011 Jul;10(7):985-97. PMID: 21531872

Wernimont AK, Amani M, Qiu W, Pizarro JC, Artz JD, Lin YH, Lew J, Hutchinson A, Hui R. Structures of parasitic CDPK domains point to a common mechanism of activation. Proteins. 2011 Mar;79(3):803-20. PMID: 21287613

Artz JD, Wernimont AK, Dunford JE, Schapira M, Dong A, Zhao Y, Lew J, Russell RG, Ebetino FH, Oppermann U, Hui R. “Molecular characterization of a novel geranylgeranyl pyrophosphate synthase from Plasmodium parasites.” J Biol Chem. 2011 Feb 4;286(5):3315-22. PMID: 21084289

Fentress SJ, Behnke MS, Dunay IR, Mashayekhi M, Rommereim LM, Fox BA, Bzik DJ, Taylor GA, Turk BE, Lichti CF, Townsend RR, Qiu W, Hui R, Beatty WL, Sibley LD. Phosphorylation of immunity-related GTPases by a Toxoplasma gondii-secreted kinase promotes macrophage survival and virulence. Cell Host Microbe. 2010 Dec 16;8(6):484-95.

El Bakkouri M, Pow A, Mulichak A, Cheung KL, Artz JD, Amani M, Fell S, de Koning-Ward TF, Goodman CD, McFadden GI, Ortega J, Hui R, Houry WA. The Clp chaperones and proteases of the human malaria parasite Plasmodium falciparum. J Mol Biol. 2010 Dec 3;404(3):456-77. PMID: 20887733

Hliscs M, Sattler J, Tempel W, Artz JD, Dong A, Hui R, Matuschewski K, Schuler H. Structure and function of a G-actin sequestering protein with a vital role in malaria oocyst development inside the mosquito vector. J Biol Chem. 2010 Apr 9; 285(15):11572-83. PMID: 20083609

Frearson JA, Brand S, McElroy SP, Cleghorn LAT, Smid O, Stoganovski L, Price HP, Guther ML, Torrie LS, Robinson DA, Hallyburton I, Mpamhanga CP, Brannigan JA, Wilkinson AJ, Hodgkinson M, Hui R, Qiu W, Raimi OG, van Aalten DMF, Brenk R, Gilbert IH, Read KD, Fairlamb AH, Ferguson MAJ, Smith FD, Wyatt PG. N-Myristoyltransferase inhibitors: new leads for the treatment of human African trypanosomiasis. Nature. 2010 Apr 1;464(7289):728-32.

Wernimont A, Artz JD, Finerty P, Lin Y, Amani M, Allali-Hassani A, Senisterra G, Vedadi M, Tempel W, Mackenzie F, Chau I, Lourido S, Sibley LD, Hui R. Structures of apicomplexan calcium-dependent protein kinases reveal mechanism of activation by calcium. Nature Structural and Molecular Biology. 2010 May;17(5):596-601

Lourido S, Shuman J, Zhang C, Shokat KM, Hui R, Sibley LD. Calcium-dependent protein kinase 1 is an essential regulator of exocytosis in Toxoplasma. Nature. 2010 May 20 65(7296):359-62. PMID: 20485436

BaksztR, WernimontAK, Allali-HassaniA, HillsT, HuiR and Pizarro JC. The crystal structure of Toxoplasma pyruvate kinase. PLoS One. Sep 2010. PMID: 20856875

Mariño K, Sampaio-Güther ML, Wernimont AK, Amani M, Hui R, Ferguson MA. Identification, subcellular localization, biochemical properties and high-resolution crystal structure of Trypanosoma brucei UDP-glucose pyrophosphorylase. Glycobiology. Aug 2010. PMID: 20724435

Qiu W, Wernimont A, Tang K, Taylor S, Lunin V, Schapira M, Fentress S, Hui R, Sibley L. Novel structural and regulatory features of rhoptry secretory kinases in Toxoplasma gondii. EMBO J. 2009 Apr 8;28(7):969-79.

Sibley LD, Qiu W, Fentress S, Taylor SJ, Khan A, Hui R. Forward genetics in Toxoplasma gondii reveals a family of rhoptry kinases that mediates pathogenesis. Eukaryot Cell. 2009, August; 8(8):1085-93.

Crowther GJ, Napuli AJ, Thomas AP, Chung DJ, Kovzun KV, Leibly DJ, Castaneda LJ, Bhandari J, Damman CJ, Hui R, Hol WG, Buckner FS, Verlinde CL, Zhang Z, Fan E, van Voorhis WC. Buffer optimization of thermal melt assays of Plasmodium proteins for detection of small-molecule ligands. J Biomol Screen. 2009, July; 14(6):700-7.

Alag R, Bharatham N, Dong A, Hills T, Harikishore A, Widjaja AA, Shochat SG, Hui R, Yoon HS. Crystallographic structure of the tetratricopeptide repeat domain of Plasmodium falciparum FKBP35 and its molecular interaction with Hsp90 C-terminal pentapeptide. Protein Sci. 2009, Oct; 18(10):2115-24.

Artz J, Dunford J, Arrowood M, Dong A, Chruszcz M, Kavanagh K, Minor W, Russell R, Ebetino F, Oppermann O and Hui R. Targeting a uniquely nonspecific prenyl synthase with bisphosphonates to combat cryptosporidiosis. Chem Biol. 2008 Dec 22; 15(12): 1296-306.

Vedadi M, Lew J, Artz J, Amani M, Zhao Y, Dong A, Wasney GA, Gao M, Hills T, Brokx S, Qiu W, Sharma S, Diassiti A, Alam Z, Melone M, Mulichak A, Wernimont A, Bray J, Loppnau P, Plotnikova O, Newberry K, Sundararajan E, Houston S, Walker J, Tempel W, Bochkarev A, Kozieradski I, Edwards A, Arrowsmith C, Roos D, Kain K, Hui R. “Genome-scale protein expression and structural biology of Plasmodium falciparum and related Apicomplexan organisms”, Mol Biochem Parasitology 2007, Jan, 151(1):100-10.

Bello AM, Poduch E, Fujihashi M, Amani M, Li Y, Crandall I, Hui R, Lee PI, Kain KC, Pai EF, Kotra LP. A potent, covalent inhibitor of orotidine 5'-monophosphate decarboxylase with antimalarial activity. J Med Chem. 2007 Mar 8;50(5):915-21.

Dufe VT, Qiu W, Müller IB, Hui R, Walter RD, Al-Karadaghi S. Crystal structure of Plasmodium falciparum spermidine synthase in complex with the substrate decarboxylated S-adenosylmethionine and the potent inhibitors 4MCHA and AdoDATO. J Mol Biol. 2007 Oct 12;373(1):167-77


Contact

Email: structuralparasitology[at]gmail [dot] com

Mailing address:

Raymond Hui
Structural Genomics Consortium
MaRS South Tower, 7th floor
101 College St.
Toronto, Ontario
Canada M5G 1L7

Social media links:

 

Alumni

Tanya Hills (2005 – 2011)

Mirela Neculai (2010 - 2011)

Jody Weadge (2010 – 2011)

Verena Brand (2008 - 2010)

Alex Periteanu (2010 – 2011)

Ashley Hutchinson (2008 – 2010)

Wei Qiu (2005 – 2010)

Kate Newberry (2006 – 2007)

Stephen Brokx (2005 – 2007)

Fabien Marino (2004 – 2006)

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