Rogala, Kacper BDynes, Nicola JHatzopoulos, Georgios NYan, JunPong, Sheng KaiRobinson, Carol VDeane, Charlotte MGönczy, PierreVakonakis, Ioannis2015-12-092015-12-092015-12-09201510.7554/eLife.07410https://infoscience.epfl.ch/handle/20.500.14299/121565Centrioles are microtubule-based organelles crucial for cell division, sensing and motility. In Caenorhabditis elegans, the onset of centriole formation requires notably the proteins SAS-5 and SAS-6, which have functional equivalents across eukaryotic evolution. Whereas the molecular architecture of SAS-6 and its role in initiating centriole formation are well understood, the mechanisms by which SAS-5 and its relatives function is unclear. Here, we combine biophysical and structural analysis to uncover the architecture of SAS-5 and examine its functional implications in vivo. Our work reveals that two distinct self-associating domains are necessary to form higher-order oligomers of SAS-5: a trimeric coiled coil and a novel globular dimeric Implico domain. Disruption of either domain leads to centriole duplication failure in worm embryos, indicating that large SAS-5 assemblies are necessary for function in vivo.text::journal::journal article::research article