When:
Monday, November 11, 2019
10:00 AM - 11:00 AM CT
Where: Robert H Lurie Medical Research Center, Baldwin Auditorium, 303 E. Superior, Chicago, IL 60611 map it
Audience: Faculty/Staff - Student - Post Docs/Docs - Graduate Students
Contact:
Beverly A Kirk
(312) 503-5217
Group: Biochemistry and Molecular Genetics Distinguished Lectureship
Category: Lectures & Meetings
The Department of Biochemistry and Molecular Genetics presents:
Geeta Narlikar, PhD
Professor of Biochemistry and Biophysics
Lewis and Ruth Cozen Chair
University of California, San Francisco
Lecture Title: The Role of Phase-Separation in Genome Regulation
Different cell types in a given animal, such as heart cells and brain cells display different behaviors because they express different sets of genes. Yet, 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? Which genes are on and which genes are turned off is controlled in part by how their underlying DNA sequences are packaged. DNA is packaged by wrapping it around specific proteins called histones to generate bead-like structures called nucleosomes. Strings of nucleosomes are then further folded to condense the underlying DNA and make it less accessible. Structures called heterochromatin are thought to be particularly effective at compacting strings of nucleosomes and turning off the underlying genes. We’ve discovered that nucleosomes, rather than acting as rigid packaging units act as shape-shifters to regulate access to the wrapped DNA. We’ve further found that proteins named HP1 proteins, which are core components of heterochromatin, can sequester and compact packaged DNA into phase-separated droplets. Interestingly, within these droplets HP1 molecules are dynamic and display liquid-like properties, but yet are able to keep different genomic regions sequestered from one another. I will discuss the underlying experiments and the new regulatory implications arising from these biophysical properties of the packaged genome.