Plk4 triggers autonomous de novo centriole biogenesis and maturation

Abstract

23Centrioles form centrosomes and cilia. In most proliferating cells, centrioles assemble 24 through canonical duplication, which is spatially, temporally and numerically regulated 25 by the cell cycle and the presence of mature centrioles. However, in certain cell-types, 26 centrioles assemble de novo, yet by poorly understood mechanisms. Here, we 27 established a controlled system to investigate de novo centriole biogenesis, using 28Drosophila melanogaster egg explants overexpressing Polo-like kinase 4 (Plk4), a 29 trigger for centriole biogenesis. At high Plk4 concentration, centrioles form de novo, 30 mature and duplicate, independently of cell cycle progression and of the presence of 31 other centrioles. We show that Plk4 concentration determines the kinetics of centriole 32 assembly. Moreover, our results suggest Plk4 operates in a switch-like manner to control 33

Biophysical and Quantitative Principles of Centrosome Biogenesis and Structure

“…observed before de novo centriole biogenesis in the mouse early embryo (Courtois et al 2012) and in human cells after centriole removal (Khodjakov et al 2002) (Figure 2a). Furthermore, MTOCs and PCM proteins were also suggested to play a role in promoting de novo centriole assembly in Physcomitrium patens (Gomes Pereira et al 2020) and in D. melanogaster (Nabais et al 2021), respectively. Conceivably, microtubules could drive or facilitate the concentration of PCM and/or centriolar components above a critical threshold required to trigger de novo centriole biogenesis (Figure 2a).…”