Centrioles form the core of the centrosome or microtubule-organizing center (MTOC), and serve as the basal body for ciliogenesis. To faithfully execute these functions in cycling cells, both the architecture and copy number of the centriole need to be correctly specified. The structural integrity of the centriole is established through stepwise assemblies of a series of structural components, many of which serve as the building block, scaffold, or stabilizing factor. While self-assembly is a feature of centriole formation, one or more steps of the assembly pathway are guarded by enzymatic regulators to allow quality and quantity controls. Plk4 kinase and PP2A phosphatase are two such enzymes known to closely involve in centriole assembly. However, the specific assembly step(s) controlled by Plk4 or PP2A, the relevant substrates, how the two (biochemically) opposing enzymes coordinate, and whether/how their enzymatic activities are regulated during centriole assembly remain outstanding questions. Equally unclear is the regulatory module we have recently shown to promote centriole to centrosome conversion at the late mitosis, a key process through which centriole homeostasis is maintained in proliferating cells. Despite its importance, the centriolar factors involved in centriole-to- centrosome conversion, and how these factors or activities interact with mitotic kinases are completely unknown.
The aims of this proposal are to characterize (i) the regulation and action of Plk4 & PP2A in centriole assembly, and (ii) the molecular basis and functional implications of centriole-to-centrosome conversion.

Public Health Relevance

s Abnormal number of centrioles/centrosomes is commonly seen in most cancer cells, and has been directly linked to genomic instability due to their profound effect on spindle organization. Dysfunction in the centriole or its associated structure, the cilium, is also prevalent in a large heterogeneous group of disorders collectively called ciliopathy, including e.g. Bardet-Biedl syndrome, Joubert syndrome, Meckel-Gruber syndrome, obesity, polycystic kidney disease, and primary ciliary dyskinesia. A thorough understanding of the molecular pathways vertebrate cells employ to maintain the number and structural integrity of these organelles will allow for the development of therapeutic manipulations for some of these diseases.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM088253-07
Application #
8991067
Study Section
Nuclear and Cytoplasmic Structure/Function and Dynamics Study Section (NCSD)
Program Officer
Hamlet, Michelle R
Project Start
2009-08-01
Project End
2018-12-31
Budget Start
2016-01-01
Budget End
2016-12-31
Support Year
7
Fiscal Year
2016
Total Cost
$331,012
Indirect Cost
$142,830
Name
Sloan-Kettering Institute for Cancer Research
Department
Type
DUNS #
064931884
City
New York
State
NY
Country
United States
Zip Code
10065
Fong, Chii Shyang; Ozaki, Kanako; Tsou, Meng-Fu Bryan (2018) PPP1R35 ensures centriole homeostasis by promoting centriole-to-centrosome conversion. Mol Biol Cell 29:2801-2808
Yang, T Tony; Chong, Weng Man; Wang, Won-Jing et al. (2018) Super-resolution architecture of mammalian centriole distal appendages reveals distinct blade and matrix functional components. Nat Commun 9:2023
Shulman, Avital S; Tsou, Meng-Fu Bryan (2017) Probing Cilia-Associated Signaling Proteomes in Animal Evolution. Dev Cell 43:653-655
Soni, Rajesh Kumar; Tsou, Meng-Fu Bryan (2016) A Cell-Free System for Real-Time Analyses of Centriole Disengagement and Centriole-to-Centrosome Conversion. Methods Mol Biol 1413:197-206
Fong, Chii Shyang; Mazo, Gregory; Das, Tuhin et al. (2016) 53BP1 and USP28 mediate p53-dependent cell cycle arrest in response to centrosome loss and prolonged mitosis. Elife 5:
Mazo, Gregory; Soplop, Nadine; Wang, Won-Jing et al. (2016) Spatial Control of Primary Ciliogenesis by Subdistal Appendages Alters Sensation-Associated Properties of Cilia. Dev Cell 39:424-437
Kim, Minhee; O'Rourke, Brian P; Soni, Rajesh Kumar et al. (2016) Promotion and Suppression of Centriole Duplication Are Catalytically Coupled through PLK4 to Ensure Centriole Homeostasis. Cell Rep 16:1195-1203
Wang, Won-Jing; Acehan, Devrim; Kao, Chien-Han et al. (2015) De novo centriole formation in human cells is error-prone and does not require SAS-6 self-assembly. Elife 4:
Yang, T Tony; Su, Jimmy; Wang, Won-Jing et al. (2015) Superresolution Pattern Recognition Reveals the Architectural Map of the Ciliary Transition Zone. Sci Rep 5:14096
Kim, Minhee; Fong, Chii Shyang; Tsou, Meng-Fu Bryan (2014) Centriole duplication: when PLK4 meets Ana2/STIL. Curr Biol 24:R1046-8

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