Structural basis of the 9-fold symmetry of centrioles.

Journal article

The centriole, and the related basal body, is an ancient organelle characterized by a universal 9-fold radial symmetry and is critical for generating cilia, flagella, and centrosomes. The mechanisms directing centriole formation are incompletely understood and represent a fundamental open question in biology. Here, we demonstrate that the centriolar protein SAS-6 forms rod-shaped homodimers that interact through their N-terminal domains to form oligomers. We establish that such oligomerization is essential for centriole formation in C. elegans and human cells. We further generate a structural model of the related protein Bld12p from C. reinhardtii, in which nine homodimers assemble into a ring from which nine coiled-coil rods radiate outward. Moreover, we demonstrate that recombinant Bld12p self-assembles into structures akin to the central hub of the cartwheel, which serves as a scaffold for centriole formation. Overall, our findings establish a structural basis for the universal 9-fold symmetry of centrioles.

Authors: Kitagawa, D; Vakonakis, I; Olieric, N; Hilbert, M; Keller, D

• Publication status: Published
• Journal: Cell
• Volume: 144
• Issue: 3
• Pages: 364-375
• Publication date: 2011-02-01
• DOI: 10.1016/j.cell.2011.01.008
• EISSN: 1097-4172
• ISSN: 0092-8674
• Language: English
• Keywords: Animals; Models, Molecular; Humans; Caenorhabditis; Sequence Alignment; Caenorhabditis elegans; Caenorhabditis elegans Proteins; Cell Line; Cell Cycle Proteins; Recombinant Proteins; Centrioles; Protein Multimerization; Molecular Sequence Data; Amino Acid Sequence