Hierarchical recruitment of Plk4 and regulation of centriole biogenesis by two centrosomal scaffolds, Cep192 and Cep152

Abstract

Significance Found in most eukaryotic cells, a centriole is a cylindrically shaped subcellular structure that plays an important role in various cellular processes, including mitotic spindle formation and chromosome segregation. Centriole duplication occurs only once per cell cycle, thus ensuring accurate control of centriole numbers to maintain genomic integrity. Although a growing body of evidence suggests that a Ser/Thr protein kinase, polo-like kinase 4 (Plk4), is a key regulator of centriole duplication, how Plk4 is recruited to centrosomes remains largely unknown. Here we showed that Plk4 dynamically localizes to distinct subcentrosomal regions by interacting with two hierarchically regulated scaffolds, Cep192 and Cep152. Highlighting the importance of these interactions, mutational disruption of either one of these interactions was sufficient to cripple Plk4-dependent centriole biogenesis.

Bimodal Interaction of Mammalian Polo-Like Kinase 1 and a Centrosomal Scaffold, Cep192, in the Regulation of Bipolar Spindle Formation

“…For the production of lentiviruses, transfection was performed by using a calcium phosphate coprecipitation method (13). To effectively deplete Cep192 proteins, U2OS cells were transfected twice with an siRNA against Cep192 (siCep192) (nucleotide positions 2407 to 2427) (14) and cultured for a total period of 96 h. To trap the majority of cells in either the S or M phase, cells were treated with 2.5 mM thymidine (Sigma-Aldrich) or 666 nM nocodazole (Sigma-Aldrich) for 20 h, respectively.…”

The role of mitotic kinases in coupling the centrosome cycle with the assembly of the mitotic spindle

“…Basis of the ninefold symmetry of the cartwheel structure Gudi et al, 2011;Kitagawa et al, 2011b;van Breugel et al, 2011 Cep152 Recruits Plk4 and SAS6 for the initiation of centriole duplication Cizmecioglu et al, 2010;Hatch et al, 2010;Kim et al, 2013 Cep192 Cooperates with Cep152 to recruit Plk4 to the centrosome Kim et al, 2013;Sonnen et al, 2013 Plk4 Multiple roles; see the main text Bettencourt-Dias et al, 2005;Habedanck et al, 2005;Kleylein-Sohn et al, 2007;Puklowski et al, 2011;Rogers et al, 2009;Swallow et al, 2005 Cep135 Stabilizes the cartwheel structure by interacting with SAS6 and CPAP Cottee et al, 2013;Hatzopoulos et al, 2013;Lin et al, 2013a;Roque et al, 2012 STIL Establishes the linkage between centriolar scaffold and microtubules Arquint and Nigg, 2014;Kitagawa et al, 2011a;Lin et al, 2013b Promoting procentriole elongation and determining ...…”

“…1). After centriole disengagement, the centrosomal protein Cep152 collaborates with Cep192 to recruit Plk4 to the centrosome (Cizmecioglu et al, 2010;Dzhindzhev et al, 2010;Kim et al, 2013;Sonnen et al, 2013); here, Plk4 phosphorylates Cep152, GCP6 (also known as TUBGCP6; c-tubulin complex protein 6, a component of c-TuRC), and possibly other currently unidentified factors, in order to initiate the centriole biogenesis machinery (Bahtz et al, 2012;Hatch et al, 2010). Then, SAS6, which constitutes the structural basis of the cartwheel, is loaded onto the sides of pre-existing centrioles towards the proximal ends and, together with Cep135, CPAP (also known as CENPJ) and STIL, forms the new cartwheel required for procentriole formation.…”

Choosing sides – asymmetric centriole and basal body assembly

“…Perhaps gate formation is initiated coincident with the docking of early centriole assembly factors, such as CEP152, CEP192 and PLK4 (Box 1). For example, PLK4 initially organizes as a toroid at the mother centriole during G1 but then forms a focus at the site of new centriole biogenesis prior to the loading of the cartwheel proteins Sas-6 (also known as SASS6) and STIL (Kim et al, 2013;Sonnen et al, 2012). PLK4 and its loading factors, CEP152 and CEP192, could trigger the reorganization of the PCM to accommodate the centriole.…”