Centre for Discovery Brain Sciences, Edinburgh Medical School, University of Edinburgh, Edinburgh, EH8 9XD, UK.
Department of Neurobiology, Harvard Medical School, Boston, MA, 02215, USA.
Sci Rep. 2022 Aug 3;12(1):13338. doi: 10.1038/s41598-022-17189-w.
The Drosophila chordotonal neuron cilium is the site of mechanosensory transduction. The cilium has a 9 + 0 axoneme structure and is highly sub-compartmentalised, with proximal and distal zones harbouring different TRP channels and the proximal zone axoneme also being decorated with axonemal dynein motor complexes. The activity of the dynein complexes is essential for mechanotransduction. We investigate the localisation of TRP channels and dynein motor complexes during ciliogenesis. Differences in timing of TRP channel localisation correlate with order of construction of the two ciliary zones. Dynein motor complexes are initially not confined to their target proximal zone, but ectopic complexes beyond the proximal zone are later cleared, perhaps by retrograde transport. Differences in transient distal localisation of outer and inner dynein arm complexes (ODAs and IDAs) are consistent with previous suggestions from unicellular eukaryotes of differences in processivity during intraflagellar transport. Stable localisation depends on the targeting of their docking proteins in the proximal zone. For ODA, we characterise an ODA docking complex (ODA-DC) that is targeted directly to the proximal zone. Interestingly, the subunit composition of the ODA-DC in chordotonal neuron cilia appears to be different from the predicted ODA-DC in Drosophila sperm.
果蝇听毛神经元纤毛是机械感觉转导的部位。纤毛具有 9+0 轴丝结构，高度亚区室化，近端区和远端区含有不同的 TRP 通道，并且近端区轴丝还被轴丝动力蛋白复合物修饰。动力蛋白复合物的活性对于机械转导至关重要。我们研究了纤毛发生过程中 TRP 通道和动力蛋白复合物的定位。TRP 通道定位的时间差异与两个纤毛区的构建顺序相关。动力蛋白复合物最初不限于它们的目标近端区，但近端区以外的异位复合物随后被清除，可能是通过逆行运输。外动力蛋白臂复合物 (ODA) 和内动力蛋白臂复合物 (IDA) 在瞬时远端的定位差异与单细胞真核生物中在鞭毛内运输过程中的进程性差异的先前建议一致。稳定的定位取决于它们在近端区的对接蛋白的靶向。对于 ODA，我们描述了一个直接靶向近端区的 ODA docking 复合物 (ODA-DC)。有趣的是，在听毛神经元纤毛中 ODA-DC 的亚基组成似乎与预测的果蝇精子中的 ODA-DC 不同。
