Unknown

Dataset Information

0

GRP75 modulates oncogenic Dbl-driven endocytosis derailed via the CHIP-mediated ubiquitin degradation pathway.


ABSTRACT: Chaperone-assisted proteasome degradation of oncogenic protein acts as an upstream signal controlling tumorigenesis and progression. The understanding of the co-regulation of chaperone and oncoprotein of endocytosis pathways is extremely limited. In this study, we showed for the first time that proto-Dbl (dbl proto-oncogene product) is co-enriched with mitochondrial chaperone GRP75 in endocytosis vesicles from ovarian cancer cells. onco-Dbl, produced by oncogenic mutation/degradation of proto-Dbl, markedly enhanced cellular macropinocytosis but suppressed clathrin-mediated endocytosis and clathrin-independent endocytosis pathways, presenting a derailed endocytosis phenotype. GRP75 was associated with proto-Dbl inside cells and modulated Dbl-driven endocytosis derailed by a co-regulatory mode. In spite of not being a component of the Hsc70/Hsp90/proto-Dbl complex, the degradation of proto-Dbl was promoted by GRP75 through the CHIP-mediated ubiquitin-proteasome pathway, of which GRP75 acts as a cooperator with CHIP but also acts as a competitor to Hsc70 and Hsp90 in the multiple chaperones-assisted pro-folding/pro-degradation machinery. Knockdown or inhibition of GRP75 attenuated proto-Dbl degradation and reduced the onco-Dbl level, which differentially impaired Rho GTPases activation and therefore shifted the endocytosis-derailed phenotype. Our data uncovered a novel GRP75-Dbl endocytosis regulatory axis and provided an alternative using chaperone inhibitor to shut down the oncoprotein-driven endocytosis derailment mechanism.

SUBMITTER: Niu X 

PROVIDER: S-EPMC6155137 | biostudies-literature |

REPOSITORIES: biostudies-literature

Similar Datasets

| S-EPMC3866888 | biostudies-literature
| S-EPMC3838192 | biostudies-literature
| S-EPMC10237035 | biostudies-literature
| S-EPMC5397900 | biostudies-literature
| S-EPMC4462021 | biostudies-literature
| S-EPMC6524225 | biostudies-literature
| S-EPMC3941215 | biostudies-literature
| S-EPMC4670746 | biostudies-literature
| S-EPMC9788759 | biostudies-literature
| S-EPMC5221628 | biostudies-literature