Glycogen synthase kinase 3 is a potential drug target for African trypanosomiasis therapy.

Abstract

Development of a safe, effective, and inexpensive therapy for African trypanosomiasis is an urgent priority. In this study, we evaluated the validity of Trypanosoma brucei glycogen synthase kinase 3 (GSK-3) as a potential drug target. Interference with the RNA of either of two GSK-3 homologues in bloodstream-form T. brucei parasites led to growth arrest and altered parasite morphology, demonstrating their requirement for cell survival. Since the growth arrest after RNA interference appeared to be more profound for T. brucei GSK-3 "short" (Tb10.161.3140) than for T. brucei GSK-3 "long" (Tb927.7.2420), we focused on T. brucei GSK-3 short for further studies. T. brucei GSK-3 short with an N-terminal maltose-binding protein fusion was cloned, expressed, and purified in a functional form. The potency of a GSK-3-focused inhibitor library against the recombinant enzyme of T. brucei GSK-3 short, as well as bloodstream-form parasites, was evaluated with the aim of determining if compounds that inhibit enzyme activity could also block the parasites' growth and proliferation. Among the compounds active against the cell, there was an excellent correlation between activity inhibiting the T. brucei GSK-3 short enzyme and the inhibition of T. brucei growth. Thus, there is reasonable genetic and chemical validation of GSK-3 short as a drug target for T. brucei. Finally, selective inhibition may be required for therapy targeting the GSK-3 enzyme, and a molecular model of the T. brucei GSK-3 short enzyme suggests that compounds that selectively inhibit T. brucei GSK-3 short over the human GSK-3 enzymes can be found.

• Authors: Kayode K Ojo, J Robert Gillespie, Aaron J Riechers, Alberto J Napuli, Christophe L M J Verlinde, Frederick S Buckner, Michael H Gelb, Mathias M Domostoj, Susan J Wells, Alexander Scheer, Timothy N C Wells, Wesley C Van Voorhis
• Journal: Antimicrobial agents and chemotherapy (Antimicrob Agents Chemother) Vol. 52 Issue 10 Pg. 3710-7 (Oct 2008) ISSN: 1098-6596 [Electronic] United States
• PMID: 18644955 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• DNA Primers
• DNA, Protozoan
• Protein Kinase Inhibitors
• Recombinant Proteins
• Glycogen Synthase Kinase 3

Topics

• Animals
• Base Sequence
• DNA Primers (genetics)
• DNA, Protozoan (genetics)
• Genes, Protozoan
• Glycogen Synthase Kinase 3 (antagonists & inhibitors, chemistry, genetics, metabolism)
• Humans
• Models, Molecular
• Protein Kinase Inhibitors (pharmacology)
• RNA Interference
• Recombinant Proteins (antagonists & inhibitors, chemistry, genetics, metabolism)
• Species Specificity
• Trypanosoma brucei brucei (drug effects, enzymology, genetics)
• Trypanosomiasis, African (drug therapy, parasitology)