The Indian Institute of Technology organised a talk on August 19, 2019. The details of the same are as follows:
Title: ‘Beyond the genetic code: how a shape-shifting genome controls cell fate'
Speaker: Prof. Geeta Narlikar, Professor of Biochemistry and Biophysics, University of California, San Francisco
Day & Date: Monday, August 19, 2019
Venue: Hall No.21, 2nd floor, Victor Menezes Convention Centre (VMCC), IIT Bombay
Different cell types in a given animal, such as heart cells and brain cells, display different behaviours because they express different sets of genes. They all have DNA with essentially the same sequence and thus the same set of genes. How is it that the same DNA is used to generate different cell types? Gene functionality is determined by the way their DNA is packaged, wrapped around specific proteins called histones, which create bead-like structures called nucleosomes. Strings of nucleosomes are further folded to condense the underlying DNA and make it less accessible. Structures called heterochromatin are particularly effective at compacting strings of nucleosomes and turning off the underlying genes. A few years ago, we discovered that nucleosomes, rather than acting as rigid packaging units, act as shape-shifters to regulate access to the wrapped DNA. We also found that proteins named HP1 proteins can sequester packaged DNA into phase-separated droplets. HP1 molecules are dynamic and display liquid-like properties. In the talk, the experiments that led to these findings were discussed along with a discussion on how unexpected biophysical properties of the packaged genome are leading to new ways of conceptualizing genome regulation.
About the speaker:
Prof. Geeta Narlikar is the Professor of Biochemistry and Biophysics at the University of California, San Francisco. She is a pioneer in the field of chromatin biology, where she discovered how molecular machines reorganize our genome. She studies the regulation of folding and compartmentalization of the genome that generates the many cell types that make up our body. She obtained her MSc in Chemistry from IIT Bombay in 1992 and Ph.D. from Stanford University in 1998. She carried out postdoctoral research at the Harvard Medical School. She received a distinguished alumnus award in 2018 from IIT Bombay. Besides, she was also awarded Beckman Young Investigator Award (2006), the Leukemia and Lymphoma Society Scholar Award (2008), the Outstanding Faculty Mentorship Award by the UCSF Graduate Students Association (2011) and the Deleage Prize awarded by the Deleage foundation (2017). Since 2017, Prof. Narlikar was appointed to the Lewis and Ruth Cozen Chair.