Oyama Kotaro, Arai Tomomi, Isaka Akira, Sekiguchi Taku, Itoh Hideki, Seto Yusuke, Miyazaki Makito, Itabashi Takeshi, Ohki Takashi, Suzuki Madoka, Ishiwata Shin'ichi
Department of Physics, School of Advanced Science and Engineering, Waseda University, Tokyo, Japan.
Department of Physics, School of Advanced Science and Engineering, Waseda University, Tokyo, Japan.
Biophys J. 2015 Jul 21;109(2):355-64. doi: 10.1016/j.bpj.2015.06.016.
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.
活细胞利用离子通道等生物热传感器感知绝对温度和温度的时间变化。在此，据我们所知，我们揭示了一种在单细胞内感知空间温度梯度的新机制。球形有丝分裂细胞在急剧的温度梯度（≥约0.065°C/μm；细胞内温差1.3°C）下形成定向膜延伸（极性小泡），这种温度梯度是在光学显微镜下用聚焦的1455纳米激光束局部加热产生的。另一方面，在逐渐的温度梯度或均匀加热下会形成多个非定向小泡。在加热过程中，由于肌动球蛋白复合物收缩力对称性的破坏，其分布变得不均匀，突出了肌动球蛋白复合物作为局部温度梯度传感器的作用。
