The cell’s ability to generate, sense, and respond to mechanical force is crucial to many biological processes, including cell division and differentiation. Our laboratory takes a multi-disciplinary approach, integrating quantitative micromanipulation (e.g., optical tweezers, glass microfibers), biochemical perturbation, and high-resolution fluorescence microscopy (e.g., confocal and TIRF imaging) to characterize physicochemical nature of the mitotic spindle and the cell nucleus. Through quantitative analyses of their micromechanics and molecular biochemistry, we aim to understand the principles of how cells are structured to respond to defined mechanical cues and aim ultimately to use the knowledge to control complex cellular behavior.
Images show micromanipulation experiments performed in our laboratory for examining the mechanical properties of the (A) and the cell nucleus (B). Using a pair of force-calibrated microneedles (white arrowheads), we study how these structures respond to force while maintaining their structural and functional in order to ensure the stable transmission and regulation of the genome in a cell.
Takagi J, Shimamoto Y. High-quality frozen extracts of Xenopus laevis eggs reveal size-dependent control of metaphase spindle micromechanics. Mol Biol Cell. 2017 Aug 1;28(16):2170-2177.
Shimamoto Y, Tamura S, Masumoto H, Maeshima K. Nucleosome-nucleosome interactions via histone tails and linker DNA regulate nuclear rigidity. Mol Biol Cell. 2017 Jun 1;28(11):1580-1589.
Shimamoto Y, Maeda YT, Ishiwata S, Libchaber AJ, Kapoor TM. Insights into the micromechanical properties of the metaphase spindle. Cell. 2011 Jun 24;145(7):1062-74.
Shimamoto Y, Forth S, Kapoor TM. Measuring Pushing and Braking Forces Generated by Ensembles of Kinesin-5 Crosslinking Two Microtubules. Dev Cell. 2015 Sep 28;34(6):669-81.