Open AccessDeubiquitinase USP9X Maintains Centriolar Satellite Integrity by Stabilizing Pericentriolar Material 1 Protein
Author(s) -
Ke-Jun Han,
Zhiping Wu,
Chad G. Pearson,
Junmin Peng,
Kunhua Song,
Changwei Liu
Publication year - 2018
Publication title -
journal of cell science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.384
H-Index - 278
eISSN - 1477-9137
pISSN - 0021-9533
DOI - 10.1242/jcs.221663
Subject(s) - biology , microbiology and biotechnology , deubiquitinating enzyme , satellite , computational biology , genetics , ubiquitin , gene , engineering , aerospace engineering
Centriolar satellites are small cytoplasmic granules that play important roles in regulating formation of centrosomes and primary cilia. Ubiquitination of satellite proteins, including the core satellite scaffold protein pericentriolar material 1 (PCM1), regulates centriolar satellite integrity. Currently, deubiquitinating enzymes that control centriolar satellite integrity have not been identified. In this study, we find that the deubiquitinase USP9X binds PCM1, and antagonizes PCM1 ubiquitination to protect it from proteasomal degradation. Knockdown of USP9X in human cell lines reduces PCM1 protein levels, disrupts centriolar satellite particles, and causes localization of satellite proteins, such as CEP290, to centrosomes. Interestingly, knockdown of mindbomb 1 (MIB1), a ubiquitin ligase that promotes PCM1 ubiquitination and degradation, in USP9X-depleted cells largely restores PCM1 protein levels, and corrects defects caused by the loss of USP9X. Taken together, our study reveals that USP9X is a constituent of centriolar satellites, and functions to maintain centriolar satellite integrity by stabilizing PCM1.