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Parasites - Molecular Parasitology - Nucleoside Transport - Purine and Pyrimidine Metabolism - Polyamine Biosynthesis 

Amalgamating tools from the diverse scientific disciplines of molecular biology, biochemistry, genetics, cell biology, immunocytochemistry, structural biology, and computational chemistry, the Ullman laboratory focuses on unique pathways in protozoan parasites that might be amenable to therapeutic manipulation. We have four areas of interest: (1) the purine salvage pathway; (2) the polyamine biosynthetic pathway; (3) nucleoside transporters; and (4) organellar biogenesis and protein import.

The parasite genera on which our laboratory focuses include Leishmania, Trypanosoma, Toxoplasma, and Plasmodium, the causative agents of leishmaniasis, African sleeping sickness, toxoplasmosis, and malaria, respectively. We have cloned, sequenced, and characterized the genes encoding the key proteins in all of these pathways. The genes serve as the molecular cornerstone for genetic and biochemical experiments to: (1) evaluate gene function in intact parasites using targeted gene replacmement strategies; and (2) to determine biochemical characteristics and 3-dimensional structure after gene overexpression in a variety of heterologous expression systems.

Recent Publications:

1. Liu W, Arendt CS, Gessford SK, Ntaba D, Carter NS, Ullman B. Identification and characterization of purine nucleoside transporters from Crithidia fasciculata. Mol Biochem Parasitol. 2005 Mar;140(1):1-12.

2. Hasne MP, Ullman B. Identification and characterization of a polyamine permease from the protozoan parasite Leishmania major. J Biol Chem. 2005 Apr 15;280(15):15188-94. Epub 2005 Jan 4.

3. Arastu-Kapur S, Arendt CS, Purnat T, Carter NS, Ullman B. Second-site suppression of a nonfunctional mutation within the Leishmania donovani inosine-guanosine transporter. J Biol Chem. 2005 Jan 21;280(3):2213-9. Epub 2004 Oct 22.

4. Roberts SC, Tancer MJ, Polinsky MR, Gibson KM, Heby O, Ullman B. Arginase plays a pivotal role in polyamine precursor metabolism in Leishmania. Characterization of gene deletion mutants. J Biol Chem. 2004 May 28;279(22):23668-78. Epub 2004 Mar 15.

5. Zarella-Boitz JM, Rager N, Jardim A, Ullman B. Subcellular localization of adenine and xanthine phosphoribosyltransferases in Leishmania donovani. Mol Biochem Parasitol. 2004 Mar;134(1):43-51.