Interaction between the Caenorhabditis elegans centriolar protein SAS-5 and microtubules facilitates organelle assembly.
Interaction between the Caenorhabditis elegans centriolar protein SAS-5 and microtubules facilitates organelle assembly.
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DOI：
10.1091/mbc.e17-06-0412
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发表时间：
2018-03-15
影响因子：
3.3
通讯作者：
Vakonakis I
中科院分区：
文献类型：
--
作者：
Bianchi S;Rogala KB;Dynes NJ;Hilbert M;Leidel SA;Steinmetz MO;Gönczy P;Vakonakis I
中心粒是以微管为基础的细胞器，它组织微管网络，并为纤毛和鞭毛的形成提供种子。在秀丽线虫中，新的中心粒通过一个明显依赖于中心粒蛋白SAS-5的循序渐进的过程组装。SAS-5及其在其他物种中的功能同系物形成低聚体，与中心粒蛋白SAS-6和SAS-4结合，从而在细胞器组装开始时形成一个进化上保守的结构核心。在这里，我们报道了SAS-5与微管的一种新的相互作用。微管结合需要SAS-5寡聚和与SAS-4结合位点重叠的无序蛋白质片段。结合体外和体内对选定突变体的分析表明，SAS-5-微管相互作用促进了线虫胚胎中中心粒的组装。我们的发现导致我们提出，SAS-5寡聚和微管结合的相互依赖反映了亲和力机制，这也加强了SAS-5与其他中心粒成分的联系，从而促进了细胞器的组装。
Centrioles are microtubule-based organelles that organize the microtubule network and seed the formation of cilia and flagella. New centrioles assemble through a stepwise process dependent notably on the centriolar protein SAS-5 in Caenorhabditis elegans. SAS-5 and its functional homologues in other species form oligomers that bind the centriolar proteins SAS-6 and SAS-4, thereby forming an evolutionarily conserved structural core at the onset of organelle assembly. Here, we report a novel interaction of SAS-5 with microtubules. Microtubule binding requires SAS-5 oligomerization and a disordered protein segment that overlaps with the SAS-4 binding site. Combined in vitro and in vivo analysis of select mutants reveals that the SAS-5–microtubule interaction facilitates centriole assembly in C. elegans embryos. Our findings lead us to propose that the interdependence of SAS-5 oligomerization and microtubule binding reflects an avidity mechanism, which also strengthens SAS-5 associations with other centriole components and, thus, promotes organelle assembly.