9-fold ring of centrioles
For 50 years researchers have puzzled over how the animal cell manages to organize a critical component of cell division into a microtubule-rimmed cylinder with a distinctive nine-spoked cross-section. Now, Pierre Gönczy, at the Swiss Federal Institute of Technology, and colleagues have discovered that the three-dimensional structure of a key protein component directly specifies this unusual pattern.
Barrel-shaped organelles, the centrioles organize the spindle fibers that pull paired chromosomes apart during cell division. They also form the basal bodies of cilia and flagella in all eukaryotes possessing these appendages. Centriolar structure has long been a curiosity among researchers because nobody could figure out how the ninefold structure formed. It’s a “big question that has always perplexed people,” says Andrew Fry at the University of Leicester.
The Scientist editorial – link to original.
The paper: D. Kitagawa et al., “Structural basis of the 9-fold symmetry of centrioles,” Cell, 144:364-75, 2011. Free F1000 evaluation