Gabryjonczyk, Anna-Maria. On the regulation of centriole duplication in human cells : exploring the interactions of polo-like kinase 4 with the centrosomal proteins Cep192 and STIL. 2015, PhD Thesis, University of Basel, Faculty of Science.
Official URL: http://edoc.unibas.ch/diss/DissB_11584
Here, we identify Cep192 and STIL as novel interaction partners of PLK4-PB1-PB2 and PLK4-PB3, respectively. In the first part of this study, we reveal that Cep192 directly binds PB1-PB2 via a short region within its N-terminus, which contains conserved patches of acidic residues. We show that also in the case of Cep152 a short N-terminal acidic region is critical for the binding to PB1-PB2. These acidic regions of Cep192 and Cep152 enable electrostatic interactions with positively charged residues of the PB1-PB2 domain in order to promote PLK4 centriolar recruitment (Sonnen et al., 2013). In the second part of this study, we identify STIL as the first known binding partner of PLK4-PB3. We show that the coiled-coil motif of STIL (STIL-CC) is necessary and sufficient for this interaction and thus important for centriole duplication. Based on a collaboration for crystallographic and NMR analyses, we furthermore demonstrate that PB3 adopts a canonical PB fold, and that the PLK4-PB3/STIL-CC binding mimics coiled-coil formation. Analysis of structure-guided STIL mutants suggests a dual binding mode of STIL-CC to PB3 and L1 of PLK4 (linker between the catalytic domain and the PB domains). Taken together, we propose a speculative model for the initial steps of procentriole assembly according to which PLK4 is recruited to centrioles by electrostatic interactions between PB1-PB2 and Cep192/Cep152, and thereafter is stabilized and activated via STIL-CC binding to PB3 and L1.
|Advisors:||Nigg, Erich A. and Scheiffele, Peter|
|Faculties and Departments:||05 Faculty of Science > Departement Biozentrum > Growth & Development > Cell Biology (Nigg)|
|Bibsysno:||Link to catalogue|
|Number of Pages:||1 Online-Ressource (113 Seiten)|
|Last Modified:||30 Jun 2016 10:59|
|Deposited On:||27 May 2016 12:25|
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