Regulation of OGT by URI in Response to Glucose Confers c-MYC-Dependent Survival Mechanisms.
Cancer cells can adapt and survive under low nutrient conditions, but underlying mechanisms remain poorly explored. We demonstrate here that glucose maintains a functional complex between the co-chaperone URI, PP1γ, and OGT, the enzyme catalyzing O-GlcNAcylation. Glucose deprivation induces the acti...
| Authors: | , , , , , , , , , , |
|---|---|
| Format: | article |
| Publication Date: | 2016 |
| Country: | España |
| Institution: | Instituto de Salud Carlos III (ISCIII) |
| Repository: | Repisalud |
| Language: | English |
| OAI Identifier: | oai:repisalud.isciii.es:20.500.12105/17401 |
| Online Access: | http://hdl.handle.net/20.500.12105/17401 |
| Access Level: | Open access |
| Keyword: | Animals Glucose Glucose Tolerance Test HEK293 Cells HeLa Cells Humans |
| Summary: | Cancer cells can adapt and survive under low nutrient conditions, but underlying mechanisms remain poorly explored. We demonstrate here that glucose maintains a functional complex between the co-chaperone URI, PP1γ, and OGT, the enzyme catalyzing O-GlcNAcylation. Glucose deprivation induces the activation of PKA, which phosphorylates URI at Ser-371, resulting in PP1γ release and URI-mediated OGT inhibition. Low OGT activity reduces O-GlcNAcylation and promotes c-MYC degradation to maintain cell survival. In the presence of glucose, PP1γ-bound URI increases OGT and c-MYC levels. Accordingly, mice expressing non-phosphorylatable URI (S371A) in hepatocytes exhibit high OGT activity and c-MYC stabilization, accelerating liver tumorigenesis in agreement with c-MYC oncogenic functions. Our work uncovers that URI-regulated OGT confers c-MYC-dependent survival functions in response to glucose fluctuations. |
|---|