Light-responsive regulation of ciliary motility is known to be conducted through modulation of dyneins, but the mechanism is not fully understood. Here, we report a novel subunit of the two-headed f/I1 inner arm dynein, named DYBLUP, in animal spermatozoa and a unicellular green alga. This subunit contains a BLUF (sensors of blue light using FAD) domain that appears to directly modulate dynein activity in response to light. DYBLUP (dynein-associated BLUF protein) mediates the connection between the f/I1 motor domain and the tether complex that links the motor to the doublet microtubule. Chlamydomonas lacking the DYBLUP ortholog shows both positive and negative phototaxis but becomes acclimated and attracted to high-intensity blue light. These results suggest a mechanism to avoid toxic strong light via direct photoregulation of dyneins.

已知纤毛运动的光响应调节是通过调节动力蛋白进行的，但其机制尚不完全清楚。在这里，我们报告了一种新的双头 f/I1 内臂动力蛋白亚基，名为 DYBLUP，在动物精子和单细胞绿藻中。该亚基包含一个 BLUF（使用 FAD 的蓝光传感器）结构域，该结构域似乎可以直接调节动力蛋白活性以响应光。DYBLUP（动力蛋白相关的 BLUF 蛋白）介导 f/I1 运动结构域和将运动连接到双峰微管的系链复合体之间的连接。衣藻缺乏 DYBLUP 直系同源物显示出正向和负向趋光性，但会适应并被高强度蓝光吸引。这些结果表明了一种通过动力蛋白的直接光调节来避免有毒强光的机制。