Centriolar satellites are acentriolar assemblies of centrosomal proteins
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Valentina Quarantotti [2] ; Jia‐Xuan Chen [2] ; Julia Tischer [2] ; Carmen Gonzalez Tejedo [2] ; Evaggelia K Papachristou [2] ; Clive S D'Santos [2] ; John V Kilmartin [1] ; Martin L Miller [2] ; Fanni Gergely [2]
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[1] MRC Laboratory of Molecular Biology
MRC Laboratory of Molecular Biology
Cambridge District, Reino Unido
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[2] 1 Cancer Research UK Cambridge Institute Li Ka Shing Centre University of Cambridge Cambridge UK
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- Localización: EMBO journal: European Molecular Biology Organization, ISSN 0261-4189, Vol. 38, Nº. 14, 2019
- Idioma: inglés
- Enlaces
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Resumen
Centrioles are core structural elements of both centrosomes and cilia. Although cytoplasmic granules called centriolar satellites have been observed around these structures, lack of a comprehensive inventory of satellite proteins impedes our understanding of their ancestry. To address this, we performed mass spectrometry (MS)‐based proteome profiling of centriolar satellites obtained by affinity purification of their key constituent, PCM1, from sucrose gradient fractions. We defined an interactome consisting of 223 proteins, which showed striking enrichment in centrosome components. The proteome also contained new structural and regulatory factors with roles in ciliogenesis. Quantitative MS on whole‐cell and centriolar satellite proteomes of acentriolar cells was performed to reveal dependencies of satellite composition on intact centrosomes. Although most components remained associated with PCM1 in acentriolar cells, reduced cytoplasmic and satellite levels were observed for a subset of centrosomal proteins. These results demonstrate that centriolar satellites and centrosomes form independently but share a substantial fraction of their proteomes. Dynamic exchange of proteins between these organelles could facilitate their adaptation to changing cellular environments during development, stress response and tissue homeostasis.
