Biophysical Society Thematic Meeting| Aussois 2019

Biology and Physics Confront Cell-Cell Adhesion

Monday Speaker Abstracts

TENSION-DEPENDENT STABILIZATION OF E-CADHERIN LIMITS CELL-CELL CONTACT EXPANSION Carl-Philipp Heisenberg 1 ; 1 IST Austria, Heisenberg lab, Klosterneuburg, Austria Tension of the actomyosin cell cortex plays a key role in determining cell-cell contact growth and size. The level of cortical tension outside of the cell-cell contact, pulling at the contact edge, is generally thought to scale with the total size to which a cell-cell contact can grow 1,2 . Here we have used primary germ layer progenitor cells from zebrafish to show that this relationship only applies to a narrow range of cortical tensions, and that above a critical threshold level of cortical tension, tension inversely scales with contact size. This switch from cortical tension increasing to decreasing progenitor cell-cell contact size is caused by cortical tension promoting E-cadherin anchoring to the actomyosin cytoskeleton, thereby increasing clustering and stability of E-cadherin at the contact. Once tension-mediated E-cadherin stabilization at the contact exceeds a critical threshold level, the rate by which the contact expands in response to pulling forces from the cortex sharply drops, leading to smaller contacts at physiologically relevant timescales of contact formation. Thus, the activity of cortical tension in expanding cell-cell contact size is limited by tension stabilizing E-cadherin-actomyosin complexes at the contact.

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