Parasitology & Microbes

Biography

Biography: Purna Sudha Bindu Ambaru

Abstract

Leishmania species are flagellated unicellular eukaryotes that are known to cause a fatal vector-borne parasitic disease called Leishmaniasis. Visceral leishmaniasis is a chronic and potentially fatal parasitic disease of the viscera (the internal organs, particularly the liver, spleen, bone marrow and lymph nodes) due to infection by the parasite called Leishmania donovani. There are around 8000 protein coding genes in L.donovani and unfortunately, even until now, 42% of these genes are still hypothetical genes with unknown function. Here, we have systematically characterized an actin binding protein, profilin. Leishmania parasites express only one homolog of profilin (LdPfn), which catalyzes nucleotide exchange on G-actin and promotes actin polymerization at its low concentrations. However, at high concentrations, it strongly inhibits the polymerization process by sequestering actin monomers. Further, this protein is also found to be binding to poly-L-proline motifs and polyphosphoinositides. Monospecific anti-rLdPfn antibodies specifically recognized profilin protein in whole cell lysates of L. donovani promastigotes but failed to recognize profilin in human cell lysate indicating that Leishmania cells express a novel homologue of profilin. Profilin protein is found to be localized throughout the cell body, flagellum as well as in the nucleus and is found to be undergoing post-translational modification, phosphorylation. 50-60% depletion of the intracellular pool of this protein selectively affected the parasite growth and intracellular vesicle trafficking activity. Currently, we are analysing the transcriptome of the parasite and investigating the  pathways that were significantly affected in profilin deficient Leishmania cells.