Speaker: Junghyun Kim, postdoctoral research associate in the Department of Molecular Biosciences, College of Natural Sciences, Institute for Cellular and Molecular Biology, at The University of Texas at Austin

Title: "Molecular communication between environment and chromatin remodeling in the 3D landscape of gene regulation"

Abstract: Living organisms respond to their everchanging surroundings by orchestrating cellular processes through precise spatiotemporal regulation of gene expression, ensuring proper biological function. Given that changes in gene expression driven by environmental factors precede the morphological alterations, I am particularly interested in understanding how transcriptional regulators influence gene expression in response to environmental cues. In eukaryotic cells, the tightly packaged genetic material, chromatin, serves as a physical unit for gene regulation. Therefore, understanding dynamic chromatin behaviors accessible or inaccessible for transcriptional machinery upon various environmental signals is critical for gene regulation. 

In this presentation, I will outline my recent research on multiple gene regulatory mechanisms. These mechanisms illustrate how chromatin modifications, and three-dimensional (3D) chromatin structural changes are influenced by evolutionarily conserved chromatin remodeling proteins in response to diverse environmental conditions, including light and temperature. Specifically, my focus has been on elucidating the roles of VIL1, and GH1-HMGAs, in environmentally driven gene regulatory networks. One significant finding is that the environmental sensor, phytochrome B, collaborates with VIL1 to directly trigger chromatin loop in a light-dependent manner. My work suggests that the direct elicitation of chromatin remodeling by environmental sensors may empower plants to rapidly respond to dynamically changing environments. In the era of climate change, it is crucial to understand how plants achieve developmental plasticity to cope with environmental fluctuations. Therefore, I aim to enhance our understanding of how the environment influences chromatin organization through diverse routes in my future research. This will involve employing complementary approaches to elucidate the mechanistic details governing gene regulation through dynamic changes in the 3D chromatin landscape in response to environmental shifts.

Host: Michelle Guo, GDCB assistant professor

Biography: Dr. Junghyun Kim earned her Ph.D. from the Korea Advanced Institute of Science and Technology (KAIST) in South Korea, with a focus on the mechanisms underlying signaling processes of environmental sensors, particularly phytochromes, in Arabidopsis. Her thesis work includes in-depth analysis of genome-wide binding sites of PIF transcription factors, which are key negative regulators in the phytochrome signaling pathways. Kim is currently a postdoctoral fellow at Dr. Sibum Sung’s lab in the Department of Molecular Biosciences at the University of Texas at Austin. In her postdoctoral research, she expanded her focus to chromatin biology, investigating the epigenetic regulation of plant development in response to environmental stimuli, such as light and temperature. Her significant contributions include characterizing novel gene regulatory modules through the discovery of dynamic changes in histone modification and the formation of chromatin loops. These processes are regulated by environmental sensors and a variety of chromatin remodeling proteins under diverse environmental conditions.