Abstract:

Biological flows, such as cytoplasmic flow and blood flow, influence important biological processes from cell function to tissue development. However, flow force transmission mechanisms between the inside and outside of cells are not fully understood. Single-Molecule Speckle (SiMS) microscopy is a powerful technique to elucidate force transmission mechanisms by directly monitoring the molecular motion associated with flow. In this talk, Dr. Yamashiro will introduce her study that reveals a critical role of dynamic Talin unfolding in force transmission between the flowing actin network and the substrate (Yamashiro et al., Nat Commun, 2023). The SiMS approach allowed Dr. Yamashiro and her colleagues to reveal all kinetic parameters of stochastic, transient Talin linkage in live cells. She will also introduce her recent study on the effects of shear stress on membrane proteins in live cells. Her findings provide new insights into force transmission mechanisms of biological flows.

References:

[1] Yamashiro S, Rutkowski DM, Lynch KA, Liu Y, Vavylonis D, Watanabe N. Force transmission by retrograde actin flow-induced dynamic molecular stretching of Talin. Nature Communications, 14:8468, 2023.

[2] Yamashiro S, Taniguchi D, Tanaka S, Kiuchi T, Vavylonis D, Watanabe N. Convection-induced biased distribution of actin probes in live cells. Biophys. J., 116: 142–150, 2019.

Biography:

Dr. Sawako Yamashiro was born in Ginowan City, Okinawa. She obtained her PhD in 2003 for her research on the characterization of two actin-binding IQGAPS in Xenopus cells and embryos, under the guidance of Prof. Issei Mabuchi at the University of Tokyo. Dr. Yamashiro went on to do her postdoctoral research on myofibril assembly in C. elegans in the laboratory of Prof. Shoichiro Ono at the Department of Pathology, Emory University (2004-2008) and then worked on the regulation of the F-actin minus-end capping proteins with Prof. Velia Fowler at the Scripps Research Institute (2008-2011). Dr. Yamashiro joined the laboratory of Prof. Naoki Watanabe in 2011, when Prof. Watanabe was affiliated with the Graduate School of Life Science, Tohoku University, as an Assistant Professor, and then they both moved to Kyoto University in 2014. Since 2011, Dr. Yamashiro has been engaged in the development and application of single-molecule imaging in live cells. Dr. Yamashiro has been on the faculty of Graduate School of Biostudies, Kyoto University since 2014 and has recently been promoted to Associate Professor (2024). Her present biological research is focused on unravelling mechanical interactions between the interior and exterior of the cells at the molecular level.