The Caenorhabditis elegans protein SAS-5 forms large oligomeric assemblies critical for centriole formation.

Kacper B Rogala, Nicola J Dynes, Georgios N Hatzopoulos, Jun Yan, Sheng Kai Pong, Carol V Robinson, Charlotte M Deane, Pierre Gönczy, Ioannis Vakonakis.

eLife. 4:e07410. 2015 May 29.

blue & bold — Rogala Lab member
Ψ — equal contribution
@ — corresponding author

Centrioles 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.

 

PubMed: 26023830 // Journal website [open access]

Deposited structures: 4YNH, 4YV4

 

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