No stress – Hsp90 and signal transduction inLeishmania

Abstract

SUMMARYHsp90 (a.k.a. Hsp83) plays a significant role in the life cycle control of the protozoan parasiteLeishmania donovani. Rather than protectingLeishmaniaspp. against adverse and stressful environs, Hsp90 is required for the maintenance of the motile, highly proliferative insect stage, the promastigote. However, Hsp90 is also essential for survival and proliferation of the intracellular mammalian stage, the amastigote. Moreover, recent evidence shows Hsp90 and other components of large multi-chaperone complexes as substrates of stage-specific protein phosphorylation pathways, and thus as likely effectors of the signal transduction pathways inLeishmaniaspp. Future efforts should be directed towards the identification of the protein kinases and the critical phosphorylation sites as targets for novel therapeutic approaches.