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Spatial and proteomic profiling reveals centrosome‐independent features of centriolar satellites
Author(s) -
Gheiratmand Ladan,
Coyaud Etienne,
Gupta Gagan D,
Laurent Estelle MN,
Hasegan Monica,
Prosser Suzanna L,
Gonçalves João,
Raught Brian,
Pelletier Laurence
Publication year - 2019
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.15252/embj.2018101109
Subject(s) - centrosome , centriole , satellite , biology , ciliogenesis , ciliopathies , microbiology and biotechnology , microtubule , computational biology , cilium , genetics , cell , phenotype , physics , cell cycle , gene , astronomy
Centriolar satellites are small electron‐dense granules that cluster in the vicinity of centrosomes. Satellites have been implicated in multiple critical cellular functions including centriole duplication, centrosome maturation, and ciliogenesis, but their precise composition and assembly properties have remained poorly explored. Here, we perform in vivo proximity‐dependent biotin identification (Bio ID ) on 22 human satellite proteins, to identify 2,113 high‐confidence interactions among 660 unique polypeptides. Mining this network, we validate six additional satellite components. Analysis of the satellite interactome, combined with subdiffraction imaging, reveals the existence of multiple unique microscopically resolvable satellite populations that display distinct protein interaction profiles. We further show that loss of satellites in PCM 1‐depleted cells results in a dramatic change in the satellite interaction landscape. Finally, we demonstrate that satellite composition is largely unaffected by centriole depletion or disruption of microtubules, indicating that satellite assembly is centrosome‐independent. Together, our work offers the first systematic spatial and proteomic profiling of human centriolar satellites and paves the way for future studies aimed at better understanding the biogenesis and function(s) of these enigmatic structures.