A molecular mechanism for the procentriole recruitment of Ana2

McLamarrah, T. A.; Speed, S. K.; Buster, D. W.; Fagerstrom, C. J.; Galletta, B. J.; Rusan, N. M.; Rogers, G.

doi:10.1101/647149

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bioRxiv · 10.1101/647149

A molecular mechanism for the procentriole recruitment of Ana2

McLamarrah, T. A.·Speed, S. K.·Buster, D. W.·Fagerstrom, C. J.·Galletta, B. J.·Rusan, N. M.·Rogers, G.

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Abstract

Centriole duplication begins with the assembly of a pre-procentriole at a single site on a mother centriole and proceeds with the hierarchical recruitment of a conserved set of proteins, including Polo-like kinase 4 (Plk4)/ZYG-1, Ana2/SAS-5/STIL, and the cartwheel protein Sas6. During assembly, Ana2/STIL stimulates Plk4 kinase activity, and in turn, Ana2/STILs C-terminus is phosphorylated, allowing it to bind and recruit Sas6. The assembly steps immediately preceding Sas6-loading appear clear, but the mechanism underlying the upstream pre-procentriole recruitment of Ana2/STIL is not. In contrast to proposed models of Ana2/STIL recruitment, we recently showed that Drosophila Ana2 targets procentrioles independent of Plk4-binding. Instead, Ana2 recruitment requires Plk4 phosphorylation of Ana2s N-terminus, but the mechanism explaining this process is unknown. Here, we show that the amyloid-like domain of Sas4, a centriole surface protein, binds Plk4 and Ana2, and facilitates phosphorylation of Ana2s N-terminus which increases Ana2s affinity for Sas4. Consequently, Ana2 accumulates at the procentriole to induce daughter centriole assembly.

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McLamarrah, T. A., Speed, S. K., Buster, D. W., Fagerstrom, C. J., Galletta, B. J., Rusan, N. M., Rogers, G.. 2019-05-23. A molecular mechanism for the procentriole recruitment of Ana2. https://doi.org/10.1101/647149

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