Asterless is a scaffold for the onset of centriole assembly

Cancer Research UK Cell Cycle Genetics Group, University of Cambridge, Department of Genetics, Downing Street, Cambridge CB2 3EH, UK.
Nature (Impact Factor: 41.46). 10/2010; 467(7316):714-8. DOI: 10.1038/nature09445
Source: PubMed


Centrioles are found in the centrosome core and, as basal bodies, at the base of cilia and flagella. Centriole assembly and duplication is controlled by Polo-like-kinase 4 (Plk4): these processes fail if Plk4 is downregulated and are promoted by Plk4 overexpression. Here we show that the centriolar protein Asterless (Asl; human orthologue CEP152) provides a conserved molecular platform, the amino terminus of which interacts with the cryptic Polo box of Plk4 whereas the carboxy terminus interacts with the centriolar protein Sas-4 (CPAP in humans). Drosophila Asl and human CEP152 are required for the centrosomal loading of Plk4 in Drosophila and CPAP in human cells, respectively. Depletion of Asl or CEP152 caused failure of centrosome duplication; their overexpression led to de novo centriole formation in Drosophila eggs, duplication of free centrosomes in Drosophila embryos, and centrosome amplification in cultured Drosophila and human cells. Overexpression of a Plk4-binding-deficient mutant of Asl prevented centriole duplication in cultured cells and embryos. However, this mutant protein was able to promote microtubule organizing centre (MTOC) formation in both embryos and oocytes. Such MTOCs had pericentriolar material and the centriolar protein Sas-4, but no centrioles at their core. Formation of such acentriolar MTOCs could be phenocopied by overexpression of Sas-4 in oocytes or embryos. Our findings identify independent functions for Asl as a scaffold for Plk4 and Sas-4 that facilitates self-assembly and duplication of the centriole and organization of pericentriolar material.

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Available from: David M Glover, Mar 12, 2014
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    • "ification of asymmetry . Here , the centriole is the entity that biases the site of amplification . Similar local positive feedback circuits may operate in the spatial inheritance of other cellular structures . Our and others work suggest that PLK4 is translated and re - cruited to the centrosome where it accumulates ( Cizmecioglu et al . , 2010 ; Dzhindzhev et al . , 2010 ; Fode et al . , 1996 ; Hatch et al . , 2010 ; Sillibourne et al . , 2010 ; Sonnen et al . , 2012 ) until it reaches a threshold that quickly leads to full activation of the ki - nase , which is essential to trigger centriole biogenesis . Active PLK4 will then target itself for degradation ( Cunha - Ferreira et al . , 2013 ; Holland et "
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    ABSTRACT: Centrioles are essential for cilia and centrosome assembly. In centriole-containing cells, centrioles always form juxtaposed to pre-existing ones, motivating a century-old debate on centriole biogenesis control. Here, we show that trans-autoactivation of Polo-like kinase 4 (PLK4), the trigger of centriole biogenesis, is a critical event in the spatial control of that process. We demonstrate that centrioles promote PLK4 activation through its recruitment and local accumulation. Though centriole removal reduces the proportion of active PLK4, this is rescued by concentrating PLK4 to the peroxisome lumen. Moreover, while mild overexpression of PLK4 only triggers centriole amplification at the existing centriole, higher PLK4 levels trigger both centriolar and cytoplasmatic (de novo) biogenesis. Hence, centrioles promote their assembly locally and disfavor de novo synthesis. Similar mechanisms enforcing the local concentration and/or activity of other centriole components are likely to contribute to the spatial control of centriole biogenesis under physiological conditions.
    Developmental Cell 10/2015; 35(2). DOI:10.1016/j.devcel.2015.09.020 · 9.71 Impact Factor
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    • "The association of MCPH proteins with the centrosome is evolutionarily conserved with Caenorhabditis elegans (Delattre et al., 2006; Strnad and Gonczy, 2008). Three MCPH proteins, CEP152, CEP135 and STIL, interact with and promote the centrosomal localization of SAS4 (also known as CPAP or CENPJ) (Strnad and Gonczy, 2008; Cizmecioglu et al., 2010; Dzhindzhev et al., 2010; Sir et al., 2011; Brown et al., 2013; Lin et al., 2013). Failure to recruit SAS4 can attenuate centriole elongation and duplication (Schmidt et al., 2009; Comartin et al., 2013; Lin et al., 2013). "
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    ABSTRACT: eLife digest When a cell divides, the chromosomes that contain the genetic blueprint for the cell must be replicated and shared between the two new cells. A structure called the centrosome organizes the cellular machinery that separates the chromosome copies during cell division. At the center of each centrosome are two cylindrical microtubule-based structures called centrioles. Mutations in certain proteins that interact with the centrosome cause a neurodevelopmental disorder called primary microcephaly. People born with microcephaly have unusually small heads and brains. As a result, they may have difficulties with mental tasks. Scientists do not know exactly how these ‘microcephaly-associated’ proteins normally interact with the centrosomes or what they do at the centrosomes, so it is difficult to work out what goes wrong in people with microcephaly. One idea is that the proteins help to duplicate the centrioles before a cell divides. If this duplication does not occur, a cell cannot divide properly; so, people with mutations that interfere with centriole duplication cannot grow enough brain cells. Now, Kodani et al. have examined how these microcephaly-associated proteins work with ‘satellite’ proteins that congregate near the centrosome to duplicate centrioles. The satellite proteins help to recruit four microcephaly-associated proteins to the centrosome, where they are built into a ring. The microcephaly-associated proteins congregate at the centrosome in a particular order, with each protein recruiting the next one in the sequence. Once all four are in place near the centrosome, an enzyme that helps to duplicate the centrioles joins them. Further experiments suggest that mutations that affect one of the satellite proteins—known as CEP90—may cause microcephaly. Future analysis of how microcephaly-associated genes work may reveal the cell biological mechanisms by which centrioles participate in brain development. DOI:
    eLife Sciences 08/2015; 4. DOI:10.7554/eLife.07519 · 9.32 Impact Factor
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    • "The accumulation of the PCM typically initiates at the proximal end of the mother centriole and increases in size as cells transverse from interphase to mitosis (Palazzo et al., 2000). While a growing list of proteins, including Aurora-A (Hannak et al., 2001), PLK1 (Blagden and Glover, 2003), CDK5RAP2 (Lizarraga et al., 2010; Megraw et al., 1999), PCNT (Lee and Rhee, 2011; Zimmerman et al., 2004), SAS-4 (Kirkham et al., 2003; Kohlmaier et al., 2009), CEP152 (Dzhindzhev et al., 2010; Firat-Karalar et al., 2014), and SPD2 (Gomez-Ferreria et al., 2007), are found to participate in the PCM assembly and in centrosome biogenesis, the molecular architecture of the PCM and the mechanisms governing PCM assembly and centriole biogenesis are not clear. "
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    ABSTRACT: Although it is known that the centrioles play instructive roles in pericentriolar material (PCM) assembly and that the PCM is essential for proper centriole formation, the mechanism that governs centriole-PCM interaction is poorly understood. Here, we show that ATF5 forms a characteristic 9-fold symmetrical ring structure in the inner layer of the PCM outfitting the proximal end of the mother centriole. ATF5 controls the centriole-PCM interaction in a cell-cycle- and centriole-age-dependent manner. Interaction of ATF5 with polyglutamylated tubulin (PGT) on the mother centriole and with PCNT in the PCM renders ATF5 as a required molecule in mother centriole-directed PCM accumulation and in PCM-dependent centriole formation. ATF5 depletion blocks PCM accumulation at the centrosome and causes fragmentation of centrioles, leading to the formation of multi-polar mitotic spindles and genomic instability. These data show that ATF5 is an essential structural protein that is required for the interaction between the mother centriole and the PCM. Copyright © 2015 Elsevier Inc. All rights reserved.
    Cell 07/2015; 162(3). DOI:10.1016/j.cell.2015.06.055 · 32.24 Impact Factor
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