Showing papers by "Alok Bhattacharya published in 2015"

Heat Shock Protein 90 regulates encystation in Entamoeba.

Abstract: Enteric protozoan Entamoeba histolytica is a major cause of debilitating diarrheal infection worldwide with high morbidity and mortality. Even though the clinical burden of this parasite is very high, this infection is categorized as a neglected disease. Parasite is transmitted through feco-oral route and exhibit two distinct stages namely - trophozoites and cysts. Mechanism and regulation of encystation is not clearly understood. Previous studies have established the role of Heat shock protein 90 (Hsp90) in regulating stage transition in various protozoan parasites like Giardia, Plasmodium, Leishmania, and Toxoplasma. Our study for the first time reports that Hsp90 plays a crucial role in life cycle of Entamoeba as well. We identify Hsp90 to be a negative regulator of encystation in Entamoeba. We also show that Hsp90 inhibition interferes with the process of phagocytosis in Entamoeba. Overall, we show that Hsp90 plays an important role in virulence and transmission of Entamoeba.

Signaling Pathways in Entamoeba histolytica

Abstract: A variety of functions in eukaryotes, such as cell migration, contraction, secretion, proliferation, differentiation, and exocytosis, are initiated and sustained by signaling processes. Most of the signalling pathways have been described in detail for many eukaryotic systems, particularly for mammalian systems. Signaling pathways quite often consist of cell-surface receptors, intracellular components that function as adaptors and transducers including those that generate second messengers leading to either alteration in gene expression or cytoskeleton dynamics. We have rudimentary knowledge about the organization of signaling systems in Entamoeba histolytica and the mechanisms by which initiation is coupled with functional readout, in spite of identification of a number of molecules known to participate in these pathways in other organisms. In this chapter we provide a summary of our current understanding on calcium and G-protein signaling pathways of E. histolytica and their role in different biological processes.