“Live Cell Force Dynamics – Do Cell Membranes Support or Resist Tension Propagation?”

Shannon Yan

University of California, Berkeley, Department of Molecular and Cell Biology (MCB) & California Institute for Quantitative Biosciences (QB3)

Dr. Shannon Yan received her B.S. in Chemistry from National Taiwan University. She then pursued her Ph.D. in Chemistry at UC Berkeley with Prof. Ignacio Tinoco, Jr. and studied ribosome translation dynamics using mass spectrometry and force spectroscopy with optical tweezers. During postdoc with Prof. Carlos Bustamante, also at UC Berkeley, Dr. Yan expanded the scope of her research in single-molecule biophysics, from co-transcriptional RNA folding to membrane remodeling during vesicle budding. Through collaboration with the Weiner lab at UCSF, Dr. Yan advanced to investigate live cell force dynamics, where she adapted optical tweezers to monitor membrane tension during optogenetic-induced actin-driven cell protrusion/contraction in neutrophils. The outcome of this work settles a long-standing dispute in the field by revealing that membrane tension rapidly propagates across the cell and could act as an integrator of physiological signals, critical for regulating cell shape/movement. This work serves as the basis for Dr. Yan to further study membrane tension dynamics during cell division. In parallel, she is developing new molecular probes and instrumentations for the visualization of forces and tension within the cellular machinery, with the aim to apply these sensors to study spindle/microtubule dynamics during mitosis (CASI Award, BWF). Dr. Yan was also granted an NIH K99 award to study the mechanistic aspects of mitotic checkpoint proteins (MAD2), whose dynamic fold switching safeguards the mechanical progression of chromosome segregation, thus expanding our understanding on factors involved in cell division. Her overarching goal is to directly measure and broadly explore the mechanical aspects inside and around cells, thereby revealing force fields characteristic of living processes. Ultimately, Dr. Yan aims to unravel the long-missing narratives in the mechanical dimension and integrate them with the finely resolved 3D cell atlases, animating living cells at work—as well as in disease—as a 4D Physiological ‘movie.’

Host: Ron Kopito