Back to article: Centriolar satellites prevent uncontrolled degradation of centrosome proteins: a speculative review
FIGURE 1: Two core components of centriolar satellites, PCM-1 and Azi1/Cep131, sequester E3 ligase MIB1, autophagy component GABARAP, and deacetylase HDAC6, to inhibit removal and degradation of centrosome proteins by proteasomes and aggresomes, and to enable controlled degradation by autophagy. Cargoes of the centriolar satellites are in a dynamic exchange with the pericentriolar material. If bound to the pericentriolar material, MIB1 mediates poly-ubiquitylation (red) of proteins that are destined to proteasomal degradation or to HDAC6-mediated accumulation in aggresomes. Among these MIB1-substrates may be proteins of the pericentriolar material (c, grey), or centrosome-bound regulators of the autophagy pathway, such as GABARAP (G, dark yellow). Degradation of specific centrosome proteins, such as Ofd1, may occur via the autosomal pathway, supported by satellite-mediated pickup of these proteins together with GABARAP, and delivery to early autophagosomes.