The Two Unknowns of Nucleosomes: How They Are Formed and How They Are Removed

Kim, Harold D.

Title:

The Two Unknowns of Nucleosomes: How They Are Formed and How They Are Removed

dc.contributor.author	Kim, Harold D.
dc.contributor.corporatename	Georgia Institute of Technology. Institute for Bioengineering and Bioscience
dc.contributor.corporatename	Georgia Institute of Technology. School of Physics
dc.date.accessioned	2012-04-03T20:54:04Z
dc.date.available	2012-04-03T20:54:04Z
dc.date.issued	2012-03-13
dc.description	Presented on March 13, 2012 from 8:30 a.m.-9:30 a.m. at the Parker H. Petit Institute for Bioengineering & Bioscience (IBB), room 1128, Georgia Tech.	en_US
dc.description	Runtime: 60:19 minutes
dc.description.abstract	In eukaryotes, the genomic DNA is highly packaged inside the nucleus of a cell by forming beads-on-a string-like structure called nucleosomes. The propensity of a ~150-bp duplex DNA to form a nucleosome, termed the "nucleosome affinity", varies over a few orders of magnitude depending on the DNA sequence. Although nucleosome affinity is thought to be determined by DNA bending stiffness, the exact relationship between the two is not clear. Besides their role in DNA packaging, nucleosomes can repress gene expression by preventing transcription factors from accessing their DNA binding sites. Some nucleosomes, however, do not directly occlude transcription factor binding sites, and therefore their role in gene expression remains unknown. In the first part of this talk, I will explain how we measure looping kinetics and permanent curvature of various sequences of DNA using single-molecule FRET (fluorescence resonance energy transfer) and gel electrophoresis. I will then estimate nucleosome affinity of different sequences based on these measurements. In the second part, I will explain how we quantify gene expression pattern using fluorescence microscopy of yeast cells and demonstrate two examples where a nucleosome exhibits opposite effects on gene expression. Based on these results, I will present a model for nucleosome removal prior to transcription initiation.	en_US
dc.format.extent	60:19 minutes
dc.identifier.uri	http://hdl.handle.net/1853/43182
dc.language.iso	en_US	en_US
dc.publisher	Georgia Institute of Technology	en_US
dc.relation.ispartofseries	Petit Institute Breakfast Club Seminar Series
dc.subject	Biophysics	en_US
dc.subject	Genomics	en_US
dc.title	The Two Unknowns of Nucleosomes: How They Are Formed and How They Are Removed	en_US
dc.type	Moving Image
dc.type.genre	Lecture
dspace.entity.type	Publication
local.contributor.author	Kim, Harold D.
local.contributor.corporatename	Parker H. Petit Institute for Bioengineering and Bioscience
local.relation.ispartofseries	Petit Institute Breakfast Club Seminar Series
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relation.isOrgUnitOfPublication	d978f252-ad5a-4fe6-a735-21050b2d760e
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