Biophysical Journal 2015-07-21

Directional bleb formation in spherical cells under temperature gradient.

Kotaro Oyama, Tomomi Arai, Akira Isaka, Taku Sekiguchi, Hideki Itoh, Yusuke Seto, Makito Miyazaki, Takeshi Itabashi, Takashi Ohki, Madoka Suzuki, Shin'ichi Ishiwata

Index: Biophys. J. 109 , 355-64, (2015)

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Abstract

Living cells sense absolute temperature and temporal changes in temperature using biological thermosensors such as ion channels. Here, we reveal, to our knowledge, a novel mechanism of sensing spatial temperature gradients within single cells. Spherical mitotic cells form directional membrane extensions (polar blebs) under sharp temperature gradients (≥∼0.065°C μm(-1); 1.3°C temperature difference within a cell), which are created by local heating with a focused 1455-nm laser beam under an optical microscope. On the other hand, multiple nondirectional blebs are formed under gradual temperature gradients or uniform heating. During heating, the distribution of actomyosin complexes becomes inhomogeneous due to a break in the symmetry of its contractile force, highlighting the role of the actomyosin complex as a sensor of local temperature gradients. Copyright © 2015 Biophysical Society. Published by Elsevier Inc. All rights reserved.