Small Interactor of PKD2 (SIP), a novel PKD2-related single-pass transmembrane protein, is required for proteolytic processing and ciliary import of Chlamydomonas PKD2.
Small Interactor of PKD2 (SIP), a novel PKD2-related single-pass transmembrane protein, is required for proteolytic processing and ciliary import of Chlamydomonas PKD2.
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PKD2 小相互作用子 (SIP) 是一种新型 PKD2 相关单次跨膜蛋白，是衣藻 PKD2 的蛋白水解加工和纤毛输入所必需的。
DOI：
10.1101/2023.06.13.544839
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发表时间：
2023
期刊：
影响因子：
--
通讯作者：
Lechtreck,KarlF
中科院分区：
文献类型：
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作者：
Das,Poulomi;Mekonnen,Betlehem;Alkhofash,Rama;Ingle,Abha;Workman,EBlair;Feather,Alec;Liu,Peiwei;Lechtreck,KarlF
在衣原体纤毛中，纤毛病相关的TRP通道PKD 2在空间上被划分为远端区域和较小的近端区域，在远端区域PKD 2结合轴丝和细胞外鞭毛体，在较小的近端区域PKD 2更移动的并且缺乏鞭毛体。在这里，我们表明，这两个PKD 2区域建立在纤毛再生的早期，并随着纤毛的伸长而增加长度。在异常长的纤毛，只有远端区域延长，而这两个地区的长度调整纤毛缩短。在双核救援实验中，标记PKD 2迅速进入PKD 2缺陷纤毛的近端区域，而远端区域的组装受到阻碍，这表明PKD 2的轴丝对接需要从头纤毛组装。我们确定了PKD 2的小相互作用物（SIP），一个小PKD 2相关蛋白，作为PKD 2-鞭毛体复合物的一个新的组成部分。在sip突变体中，PKD 2在细胞体中的稳定性和蛋白水解加工降低，突变体纤毛中不存在PKD 2-鞭毛体复合物。像pkd 2和mst 1突变体一样，sip的游泳速度也会降低。纤毛的PKD 2突变体节拍与正常的频率和弯曲模式，但在移动细胞支持PKD 2-SIP-鞭毛体复合物在增加衣原体纤毛的有效表面的被动作用的效率较低。
In Chlamydomonas cilia, the ciliopathy-relevant TRP channel PKD2 is spatially compartmentalized into a distal region, in which PKD2 binds the axoneme and extracellular mastigonemes, and a smaller proximal region, in which PKD2 is more mobile and lacks mastigonemes. Here, we show that the two PKD2 regions are established early during cilia regeneration and increase in length as cilia elongate. In abnormally long cilia, only the distal region elongated whereas both regions adjusted in length during cilia shortening. In dikaryon rescue experiments, tagged PKD2 rapidly entered the proximal region of PKD2-deficient cilia whereas assembly of the distal region was hindered, suggesting that axonemal docking of PKD2 requires de novo ciliary assembly. We identified Small Interactor of PKD2 (SIP), a small PKD2-related protein, as a novel component of the PKD2-mastigoneme complex. In sip mutants, stability and proteolytic processing of PKD2 in the cell body were reduced and PKD2-mastigoneme complexes were absent from mutant cilia. Like the pkd2 and mst1 mutants, sip swims with reduced velocity. Cilia of the pkd2 mutant beat with normal frequency and bending pattern but were less efficient in moving cells supporting a passive role of the PKD2-SIP-mastigoneme complexes in increasing the effective surface of Chlamydomonas cilia.