Research Groups
Mammalian Biology: Malaria
Research Interests and Description
Staff Research Scientist: Pawan Malhotra, PhD
Group Leader: Virander Chauhan
Research Interests
Plasmodium secretory proteins, Merozoite Surface Protein-1, food vacuole, Hemozoin, small RNAs.
Description of Research
Identification of protein (ligand) complexes on the surface of merozoites, the invasive form of P.falciparum
Using complementary approaches, such as bacterial two hybrid analysis, in vitro interaction study and immunoprecipitation analysis, we have recently identified a large Merozoite surface protein-1 associated complex on the Plasmodium falciparum merozoite surface. The complex is specifically formed at the merozoite stage and is later shed. We are presently working on the identification and characterization of other such complexes that are specifically formed at merozoite stage and are involved in erythrocyte invasion. In addition, we have identified a hemozoin formation complex and work is underway to understand the mode of action of chloroquine and artimisnin that probably act during the hemozoin formation. Many critical molecular interactions occur between the parasite proteins and host receptors. To learn about these, we have carried out screening of a phage-library presenting random peptides with the free merozoites, this screening revealed a number of novel host receptor proteins involved in merozoite invasion. Work is being undertaken to characterize the role of these receptors in merozoite invasion of RBCs.
Analysis of food vacuole proteome and characterization of extracellular secretory antigens at asexual blood stages of P. falciparum
Plasmodium food vacuole is a lysosome like organelle where erythrocyte hemoglobin digestion occurs. Using proteome approaches, we have carried-out proteome analysis for food vacuole proteins and identified ~200 proteins associated with this organelle. Presently, work is underway to confirm the localization of these proteins within the food vacuole and to characterize their role(s). Work is also in progress to characterize the parasite secretory proteins for their role(s) in immune-modulation.
Identification of regulatory small RNA species in P. falciparum
We have generated small RNA libraries from three asexual blood stages of P. falciparum; ring, trophozoite and schizont, and identified a large number of anti-sense RNA. Work is underway to characterize the role of small RNAs in parasite development. We have also initiated studies to characterize small RNAs at 8h interval during the 48h asexual blood stage cycle.
Recent Publications
Patakottu, B.R., Singh, P.K., Malhotra, P., Chauhan, V.S., Patankar, S. 2011. In vivo analysis of translation initiation sites in Plasmodium falciparum. Mol Biol Rep In press PubMed link
Ranjan, R., Chug, M., Kumar, S., Singh, S., Kanodia, S., Hossain, M.J., Korde, R., Grover, A., Dhawan, S., Chauhan, V.S., Reddy, V.S., Mohmmed, A., Malhotra, P. 2011. Proteome analysis reveals a large Merozoite Surface Protein-1 Associated Complex on the Plasmodium falciparum merozoite surface. J Proteome Res 10, 680-691 PubMed link
Rizzi, L., Sundararaman, S., Cendic, K., Vaiana, N., Korde, R., Sinha, D., Mohmmed, A., Malhotra, P., Romeo, S. 2011. Design and synthesis of protein-protein interaction motics as Plasmodium falciparum cysteine protease, falcipain-2 inhibitors. Eu J Med Chem 46, 2083‑2090 PubMed link
Dixit, A., Singh, P.K., Sharma, G.P., Malhotra, P., Sharma, P. 2010. PfSRPK1, a novel splicing related kinase from Plasmodium falciparum. J Biol Chem 285, 38315-38323 PubMed link
Hossain, M.J., Korde, R., Singh, P.K., Kanodia, S., Ranjan, R., Ram, G., Kalsay, G.S.,Singh, R., Malhotra, P. 2010. Plasmodium falciparum Tudor staphylococcal Nuclease interacting proteins suggest its role in nuclear as well as splicing processes. Gene 468, 48-57 PubMed link
Singh, M., Mukherjee, P., Narayanasamy K., Arora, K., Somdutta, Gupta, S.,Natarajan, K., Malhotra, P. 2009. Proteome analysis of Plasmodium falciparum extracellular secretory antigens at asexual blood stages reveals a cohort of proteins with possible roles in immune modulation and signaling. Mol Cell Proteomics 8, 2102-2118 PubMed link
