Agneyo Ganguly

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Leishmania, a unicellular trypanosomatid protozoan parasite, causes a wide range of human diseases ranging from the localized self-healing cutaneous lesions to fatal visceral leishmaniasis. However, it undergoes a process of programmed cell death during treatment with the topoisomerase I poison camptothecin (CPT). The present study shows that CPT-induced(More)
Mitochondria are the principal site for the generation of cellular ATP by oxidative phosphorylation. F0F1-ATP synthase, a complex V of the electron transport chain, is an important constituent of mitochondria-dependent signaling pathways involved in apoptosis. In the present study, we have shown for the first time that 3,3'-diindolylmethane (DIM), a DNA(More)
Emergence of the bi-subunit topoisomerase I in the kinetoplastid family (Trypanosoma and Leishmania) has brought a new twist in topoisomerase research related to evolution, functional conservation and preferential sensitivities to the specific inhibitors of type IB topoisomerase family. In the present study, we describe that naturally occurring flavones(More)
ATP-binding cassette (ABC) transporters constitute the biggest family of membrane proteins involved in drug resistance and other biological activities. Resistance of leishmanial parasites to therapeutic drugs continues to escalate in developing countries and in many instances it is due to overexpressed ABC efflux pumps. Progressively adapted camptothecin(More)
The ubiquitious enzyme topoisomerase I can be targeted by drugs which turn these enzymes into cellular poisons and subsequently induce cell death. Drugs like staurosporine, which do not target topoisomerase I directly, can also lead to stabilization of topoisomerase I-DNA cleavable complexes by an indirect process of reactive oxygen species (ROS) generation(More)
Reverse gyrase is the only topoisomerase that can introduce positive supercoils into DNA in an ATP-dependent process. It has a modular structure and harnesses a helicase-like domain to support a topoisomerase activity, thereby creating the unique function of positive DNA supercoiling. The isolated topoisomerase domain can relax negatively supercoiled DNA,(More)
Kinetoplastid topoisomerase IB is an unusual bisubunit enzyme where reconstitution of the large (LdTOPIL or L) and small (LdTOPIS or S) subunits shows functional activity. It is yet to be deciphered whether one subunit or both navigate the heterodimer to its cellular DNA targets. Tethering a specific DNA-binding protein to topoisomerase I alters its site(More)
The active site tyrosine residue of all monomeric type IB topoisomerases resides in the C-terminal domain of the enzyme. Leishmania donovani, possesses unusual heterodimeric type IB topoisomerase. The small subunit harbors the catalytic tyrosine within the SKXXY motif. To explore the functional relationship between the two subunits, we have replaced the(More)
Reverse gyrase is a unique DNA topoisomerase that catalyzes the introduction of positive supercoils into DNA in an ATP-dependent reaction. It consists of a helicase domain that functionally cooperates with a topoisomerase domain. Different models for the catalytic mechanism of reverse gyrase that predict a central role of the helicase domain have been put(More)