Dr. Kenneth Zaret
Joseph Leidy Professor, Perelman School of Medicine, University of Pennsylvania
PI: Prof. Mark Currie
12 to 1 PM
IB 140 & Zoom
Title
Overcoming Chromatin Barriers to Change Cell Fate.
Abstract
Despite highly dynamic interactions between molecules in cells, most cell types maintain their distinctive gene expression state and do not spontaneously convert to markedly different states. Liver cells stay as liver cells and brain cells stay as brain cells. The primary barrier to changes in gene expression is the wrapping of nuclear DNA into arrays of nucleosomes in chromatin, which intrinsically silences gene activity. To understand how cells maintain their fate and to ultimately control cell fate at will, we need to understand how the chromatin barrier, which exists in diverse forms, impedes the access of regulatory proteins that activate new cell-specific gene networks. Our lab has identified pioneer transcription factors as developmental regulators that can target DNA sites in nucleosomes and initiate local chromatin opening that ultimately contributes to cell fate control. I will discuss how different pioneer factors can target different forms of silent chromatin and the mechanisms by which they overcome chromatin barriers.