PSMD5 Inactivation Promotes 26S Proteasome Assembly during Colorectal Tumor Progression.

ABSTRACT: Protein degradation by the ubiquitin-proteasome system (UPS) is central to protein homeostasis and cell survival. The active 26S proteasome is a large protease complex consisting of a catalytic 20S subunit and 19S regulatory particles. Cancer cells are exposed to considerable protein overload due to high metabolic rates, reprogrammed energy metabolism, and aneuploidy. Here we report a mechanism that facilitates the assembly of active 26S proteasomes in malignant cells. Upon tumorigenic transformation of the gut epithelium, 26S proteasome assembly was significantly enhanced, but levels of individual subunits were not changed. This enhanced assembly of 26S proteasomes increased further with tumor progression and was observed specifically in transformed cells, but not in other rapidly dividin

SUBMITTER: Levin A 

PROVIDER: S-EPMC6030489 | biostudies-literature | 2018 Jul

REPOSITORIES: biostudies-literature