» Articles » PMID: 38788716

MTORC1-CTLH E3 Ligase Regulates the Degradation of HMG-CoA Synthase 1 Through the Pro/N-degron Pathway

Overview
Journal Mol Cell
Publisher Cell Press
Specialty Cell Biology
Date 2024 May 24
PMID 38788716
Authors
Affiliations
Soon will be listed here.
Abstract

Mammalian target of rapamycin (mTOR) senses changes in nutrient status and stimulates the autophagic process to recycle amino acids. However, the impact of nutrient stress on protein degradation beyond autophagic turnover is incompletely understood. We report that several metabolic enzymes are proteasomal targets regulated by mTOR activity based on comparative proteome degradation analysis. In particular, 3-hydroxy-3-methylglutaryl (HMG)-coenzyme A (CoA) synthase 1 (HMGCS1), the initial enzyme in the mevalonate pathway, exhibits the most significant half-life adaptation. Degradation of HMGCS1 is regulated by the C-terminal to LisH (CTLH) E3 ligase through the Pro/N-degron motif. HMGCS1 is ubiquitylated on two C-terminal lysines during mTORC1 inhibition, and efficient degradation of HMGCS1 in cells requires a muskelin adaptor. Importantly, modulating HMGCS1 abundance has a dose-dependent impact on cell proliferation, which is restored by adding a mevalonate intermediate. Overall, our unbiased degradomics study provides new insights into mTORC1 function in cellular metabolism: mTORC1 regulates the stability of limiting metabolic enzymes through the ubiquitin system.

Citing Articles

Solute carriers: The gatekeepers of metabolism.

Khan A, Liu Y, Gad M, Kenny T, Birsoy K Cell. 2025; 188(4):869-884.

PMID: 39983672 PMC: 11875512. DOI: 10.1016/j.cell.2025.01.015.


Muskelin is a substrate adaptor of the highly regulated Drosophila embryonic CTLH E3 ligase.

Briney C, Henriksen J, Lin C, Jones L, Benner L, Rains A EMBO Rep. 2025; .

PMID: 39979464 DOI: 10.1038/s44319-025-00397-6.


mTORC1 regulates the pyrimidine salvage pathway by controlling UCK2 turnover via the CTLH-WDR26 E3 ligase.

Pham B, Yi S, Ordureau A, An H Cell Rep. 2025; 44(1):115179.

PMID: 39808525 PMC: 11840829. DOI: 10.1016/j.celrep.2024.115179.


Interplay between β-propeller subunits WDR26 and muskelin regulates the CTLH E3 ligase supramolecular complex.

Maitland M, Onea G, Owens D, Gonga-Cave B, Wang X, Arrowsmith C Commun Biol. 2024; 7(1):1668.

PMID: 39702571 PMC: 11659599. DOI: 10.1038/s42003-024-07371-3.


The hGID E3 ubiquitin ligase complex targets ARHGAP11A to regulate cell migration.

Bagci H, Winkler M, Gradel B, Uliana F, Boulais J, Mohamed W Life Sci Alliance. 2024; 7(12).

PMID: 39389782 PMC: 11467045. DOI: 10.26508/lsa.202403046.


References
1.
Thoreen C, Chantranupong L, Keys H, Wang T, Gray N, Sabatini D . A unifying model for mTORC1-mediated regulation of mRNA translation. Nature. 2012; 485(7396):109-13. PMC: 3347774. DOI: 10.1038/nature11083. View

2.
Dong C, Zhang H, Li L, Tempel W, Loppnau P, Min J . Molecular basis of GID4-mediated recognition of degrons for the Pro/N-end rule pathway. Nat Chem Biol. 2018; 14(5):466-473. DOI: 10.1038/s41589-018-0036-1. View

3.
Chen S, Wu X, Wadas B, Oh J, Varshavsky A . An N-end rule pathway that recognizes proline and destroys gluconeogenic enzymes. Science. 2017; 355(6323). PMC: 5457285. DOI: 10.1126/science.aal3655. View

4.
Heisler F, Loebrich S, Pechmann Y, Maier N, Zivkovic A, Tokito M . Muskelin regulates actin filament- and microtubule-based GABA(A) receptor transport in neurons. Neuron. 2011; 70(1):66-81. PMC: 3101366. DOI: 10.1016/j.neuron.2011.03.008. View

5.
Zhao J, Zhai B, Gygi S, Goldberg A . mTOR inhibition activates overall protein degradation by the ubiquitin proteasome system as well as by autophagy. Proc Natl Acad Sci U S A. 2015; 112(52):15790-7. PMC: 4703015. DOI: 10.1073/pnas.1521919112. View