Open AccessThe Protein Quality Control Machinery Regulates Its Misassembled Proteasome Subunits
Author(s) -
Lee Zeev Peters,
Ofri Karmon,
Galit David-Kadoch,
Rotem Hazan,
Zanlin Yu,
Michael S. Glickman,
Shay Ben-Aroya
Publication year - 2015
Publication title -
plos genetics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.587
H-Index - 233
eISSN - 1553-7404
pISSN - 1553-7390
DOI - 10.1371/journal.pgen.1005178
Subject(s) - proteasome , microbiology and biotechnology , biology , ubiquitin , proteostasis , chaperone (clinical) , protein degradation , biochemistry , gene , medicine , pathology
Cellular toxicity introduced by protein misfolding threatens cell fitness and viability. Failure to eliminate these polypeptides is associated with various aggregation diseases. In eukaryotes, the ubiquitin proteasome system (UPS) plays a vital role in protein quality control (PQC), by selectively targeting misfolded proteins for degradation. While the assembly of the proteasome can be naturally impaired by many factors, the regulatory pathways that mediate the sorting and elimination of misassembled proteasomal subunits are poorly understood. Here, we reveal how the dysfunctional proteasome is controlled by the PQC machinery. We found that among the multilayered quality control mechanisms, UPS mediated degradation of its own misassembled subunits is the favored pathway. We also demonstrated that the Hsp42 chaperone mediates an alternative pathway, the accumulation of these subunits in cytoprotective compartments. Thus, we show that proteasome homeostasis is controlled through probing the level of proteasome assembly, and the interplay between UPS mediated degradation or their sorting into distinct cellular compartments.