Summary: | <p>Centrosomes are important for many cellular processes. They comprise of a pair of
centrioles surrounded by an amorphous pericentriolar material (PCM). In Drosophila,
although more than hundreds of proteins localise to PCM, it is believed that the PCM
assembly is governed by a small subset of proteins—Polo, Spd-2 and Cnn forming a
network-like underlying scaffold. This scaffold appears to be plastic and adopts different
behaviours in many cell types. Therefore, Drosophila centrosomes allow us to understand
how a simple set of proteins are wired to satisfy biochemical and biophysical needs. In
this thesis, I describe my discovery that Cnn scaffold assembly is initiated and timed by
a Polo oscillation. Centriolar Ana1 helps recruit Polo, which inhibits Ana1 activity, resulting
in a time-delayed negative feedback oscillation. Polo then triggers a Spd-2 oscillation
which together build the Cnn scaffold. In the process, I created an automated analysis
pipeline to look into the scaffold assembly in different systems efficiently. Moreover, I
discovered that in addition to a Cnn solid scaffold centrosomes also possess a liquid
TACC scaffold that is organised by Spd-2 and Aurora A. The liquid TACC scaffold can
enrich many centrosomal proteins.</p>
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