Present address: EUROIMMUN AG, Seekamp 31, D-23560 Lübeck, Germany.
The Hsp90–Sti1 interaction is critical for Leishmania donovani proliferation in both life cycle stages
Version of Record online: 20 NOV 2012
© 2012 Blackwell Publishing Ltd
Volume 15, Issue 4, pages 585–600, April 2013
How to Cite
Hombach, A., Ommen, G., Chrobak, M. and Clos, J. (2013), The Hsp90–Sti1 interaction is critical for Leishmania donovani proliferation in both life cycle stages. Cellular Microbiology, 15: 585–600. doi: 10.1111/cmi.12057
- Issue online: 14 MAR 2013
- Version of Record online: 20 NOV 2012
- Accepted manuscript online: 29 OCT 2012 01:40AM EST
- Manuscript Accepted: 20 OCT 2012
- Manuscript Revised: 19 SEP 2012
- Manuscript Received: 18 MAY 2012
The heat shock protein 90 plays a pivotal role in the life cycle control of Leishmania donovani promoting the fast-growing insect stage of this parasite. Equally important for insect stage growth is the co-chaperone Sti1. We show that replacement of Sti1 is only feasible in the presence of additional Sti1 transgenes indicating an essential role. To better understand the impact of Sti1 and its interaction with Hsp90, we performed a mutational analysis of Hsp90. We established that a single amino acid exchange in the Leishmania Hsp90 renders that protein resistant to the inhibitor radicicol (RAD), yet does not interfere with its functionality. Based on this RAD-resistant Hsp90, we established a combined chemical knockout/gene complementation (CKC) approach. We can show that Hsp90 function is required in both insect and mammalian life stages and that the Sti1-binding motif of Hsp90 is crucial for proliferation of insect and mammalian stages of the parasite. The Sti1-binding motif in Leishmania Hsp90 is suboptimal – optimizing the motif increased initial intracellular proliferation underscoring the importance of the Hsp90–Sti1 interaction for this important parasitic protozoan. The CKC strategy we developed will allow the future analysis of more Hsp90 domains and motifs in parasite viability and infectivity.