학술논문

The conversion of formate into purines stimulates mTORC1 leading to CAD-dependent activation of pyrimidine synthesis
Document Type
Academic Journal
Source
Cancer & Metabolism. September 21, 2020, Vol. 8 Issue 1
Subject
United States
Language
English
ISSN
2049-3002
Abstract
Background Mitochondrial serine catabolism to formate induces a metabolic switch to a hypermetabolic state with high rates of glycolysis, purine synthesis and pyrimidine synthesis. While formate is a purine precursor, it is not clear how formate induces pyrimidine synthesis. Methods Here we combine phospho-proteome and metabolic profiling to determine how formate induces pyrimidine synthesis. Results We discover that formate induces phosphorylation of carbamoyl phosphate synthetase (CAD), which is known to increase CAD enzymatic activity. Mechanistically, formate induces mechanistic target of rapamycin complex 1 (mTORC1) activity as quantified by phosphorylation of its targets S6, 4E-BP1, S6K1 and CAD. Treatment with the allosteric mTORC1 inhibitor rapamycin abrogates CAD phosphorylation and pyrimidine synthesis induced by formate. Furthermore, we show that the formate-dependent induction of mTOR signalling and CAD phosphorylation is dependent on an increase in purine synthesis. Conclusions We conclude that formate activates mTORC1 and induces pyrimidine synthesis via the mTORC1-dependent phosphorylation of CAD.
Author(s): Jacqueline Tait-Mulder[sup.1], Kelly Hodge[sup.1], David Sumpton[sup.1], Sara Zanivan[sup.1,2] and Alexei Vazquez[sup.1,2] Background Cells activate metabolic pathways during differentiation and de-differentiation. The activation of one or more biochemical reactions can, [...]