Self-assembly of pericentriolar material in interphase cells lacking centrioles

Abstract

The major microtubule-organizing center (MTOC) in animal cells, the centrosome, comprises a pair of centrioles surrounded by pericentriolar material (PCM), which nucleates and anchors microtubules. Centrosome assembly depends on PCM binding to centrioles, PCM self-association and dynein-mediated PCM transport, but the self-assembly properties of PCM components in interphase cells are poorly understood. Here, we used experiments and modeling to study centriole-independent features of interphase PCM assembly. We showed that when centrioles are lost due to PLK4 depletion or inhibition, dynein-based transport and self-clustering of PCM proteins are sufficient to form a single compact MTOC, which generates a dense radial microtubule array. Interphase self-assembly of PCM components depends on γ-tubulin, pericentrin, CDK5RAP2 and ninein, but not NEDD1, CEP152 or CEP192. Formation of a compact acentriolar MTOC is inhibited by AKAP450-dependent PCM recruitment to the Golgi or by randomly organized CAMSAP2-stabilized microtubules, which keep PCM mobile and prevent its coalescence. Linking of CAMSAP2 to a minus-end-directed motor leads to the formation of an MTOC, but MTOC compaction requires cooperation with pericentrin-containing self-clustering PCM. Our data reveal that interphase PCM contains a set of components that can self-assemble into a compact structure and organize microtubules, but PCM self-organization is sensitive to motor- and microtubule-based rearrangement.

Centriolar satellites are sites of translation of centrosomal and ciliary proteins

“…After 2 further washes with PBS (5min each) and once with PBS-Tween-20, coverslips were mounted on slides with Vectashield. For immunofluorescence experiments including the mouse anti-hsPCM1 (G-6, Santa Cruz) antibody, we followed the protocol described in ( 78 ).…”

Conservation of oocyte development in germline cysts from Drosophila to mouse

“…Additionally, CAMSAP proteins bind and stabilize Golgi-nucleated MT minus ends, including the mouse oocyte-expressed CAMSAP1, a Patronin ortholog. In cultured cells, loss of the centriolar MTOC can cause Golgi-dependent MT nucleation to become predominant ( Gavilan et al, 2018 ; Martin and Akhmanova, 2018 ; Chen et al, 2022 ).…”

Microtubules in Motion: dynamics and diversity of the microtubule cytoskeleton

“…This could indicate that the balance between MT motility into opposite directionalities is slightly changed and gradually alters 3 overall MT organization. Alternatively, this could indirectly result from a mispositioning of MT nucleating organelles due to motor inactivity, such as Golgi dispersal upon Dynein inhibition (Chen et al 2022;Harada et al 1998;Corthésy-Theulaz et al 1992;Lam et al 2010;Burkhardt et al 1997;Hoogenraad et al 2001;Matanis et al 2002).…”

“…In breast cancer cells, the mechanical counterbalance between these motors tunes cell 3 shape and cell adhesion properties (Zhovmer et al 2021). Furthermore, Dynein-driven MT transport plays a role in the formation of MT asters in interphase cells (Chen et al 2022;Harada et al 1998;Corthésy-Theulaz et al 1992;Lam et al 2010;Burkhardt et al 1997;Hoogenraad et al 2001;Matanis et al 2002). Nonetheless, the extent to which motor protein-induced MT motility plays a role in the organization of a steady-state, interphase MT network has remained unclear.…”