PLK4 trans-Autoactivation Controls Centriole Biogenesis in Space

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PLK4 trans-Autoactivation Controls Centriole Biogenesis in Space

DOI: 10.1016/j.devcel.2015.09.020

Centrioles are essential for cilia and centrosome assembly. In centriole-containing cells, centrioles always form juxtaposed to pre-existing ones, motivating a century-old debate on centriole biogenesis control.

trans-autoactivation of Polo-like kinase 4 (PLK4), the trigger of centriole biogenesis, is a critical event in the spatial control of that process.

centrioles promote PLK4 activation through its recruitment and local accumulation.

centrioles promote their assembly locally and disfavor de novo synthesis. Similar mechanisms enforcing the local concentration and/or activity of other centriole components are likely to contribute to the spatial control of centriole biogenesis under physiological conditions.

Why centrioles normally form close to existing centrioles is an intriguing question that has fueled debates about the origin of centrioles as self-replicating entities.

In the future, it will be critical to study the regulation of the “activating” and degron-phosphorylation events in PLK4 and how they generate a lag time during which PLK4 can be active to phosphorylate its substrates in the right place and at the right time. In addition, it will be important to understand when and how during the cell cycle PLK4 reaches its critical concentration threshold to trigger centriole assembly.