Indian Institute of Chemical Biology, Kolkata
Suvendra Nath Bhattacharyya, currently the Principal Scientist and Head of Molecular Genetics Division of CSIR-IICB, Kolkata, is an RNA biologist. He received his PhD from CSIR-IICB Kolkata and is known for his exceptional achievements in understanding the mechanism of activity modulation of miRNAs in mammalian cancer and immune cells. He has been recognised with the Shanti Swarup Bhatnagar Prize and the National Bioscience Award in Biological Sciences in 2016. His other recognitions include the NASI-Scopus Young Scientist Award and Swarnajayanti Fellowship (2015), the AAAS/Science Young Scientist Award, the INSA Young Scientist Award, and HFSPO and EMBO long-term Fellowship. He has also received the CDA Award of HFSPO and the prestigious International Senior Research Fellowship of the Wellcome Trust, London. He was selected as an Associate of the Indian Academy of Sciences in 2010 and as a Fellow in 2017.
SESSION 3A: Inaugural lectures by Fellows/Associates
S Ananthakrishnan, Savitribai Phule Pune University, Pune
Importance of cellular organelles in controlling the miRNA-mediated gene expression in mammalian cells
miRNA-mediated repression controls the expression of more than half of the protein coding genes in metazoan animals. Translation repression is associated with target mRNA degradation initiated by decapping and deadenylation of the repressed mRNAs. Earlier evidence suggests Endoplasmic Reticulum (ER) as the site where miRNPs interact with their targets before the translation repression sets in, but the subcellular location of subsequent degradation of miRNA repressed messages was unidentified. The speaker and his group has explored the subcellular distribution of essential components of degradation machineries of miRNA-target mRNAs. They have noted that interaction of target mRNAs with AGO2 protein on ER precedes the relocalization of repressed messages to Multivesicular Bodies (MVBs). The repressed messages subsequently get deadenylated, lose their interaction with AGO2 and also become decapped. Blocking maturation of endosomes to late endosome and MVBs by targeting the endosomal protein HRS, uncouples miRNA-mediated translation repression from target RNA degradation. HRS is also targeted by the intracellular parasite Leishmania donovani that curtails HRS level in infected cells to prevent uncoupling of mRNA–AGO2 interaction, prevent degradation of translationally repressed messages and thus stop recycling of miRNPs pre-engaged in repression. Importance of other players in this process will be discussed.