Department of Biotechnology
inStem (Institute for Stem Cell Science and Regenerative Medicine)

Methionine coordinates a hierarchically organized anabolic program enabling proliferation.

Publication Type

Journal Article

Date of Publication

December 15, 2018

Journal

Molecular biology of the cell

Volume/Issue

29/26

ISSN

1939-4586

Methionine availability during overall amino acid limitation metabolically reprograms cells to support proliferation, the underlying basis for which remains unclear. Here we construct the organization of this methionine-mediated anabolic program using yeast. Combining comparative transcriptome analysis and biochemical and metabolic flux-based approaches, we discover that methionine rewires overall metabolic outputs by increasing the activity of a key regulatory node. This comprises the pentose phosphate pathway (PPP) coupled with reductive biosynthesis, the glutamate dehydrogenase (GDH)-dependent synthesis of glutamate/glutamine, and pyridoxal-5-phosphate (PLP)-dependent transamination capacity. This PPP-GDH-PLP node provides the required cofactors and/or substrates for subsequent rate-limiting reactions in the synthesis of amino acids and therefore nucleotides. These rate-limiting steps in amino acid biosynthesis are also induced in a methionine-dependent manner. This thereby results in a biochemical cascade establishing a hierarchically organized anabolic program. For this methionine-mediated anabolic program to be sustained, cells co-opt a “starvation stress response” regulator, Gcn4p. Collectively, our data suggest a hierarchical metabolic framework explaining how methionine mediates an anabolic switch.

Alternate Journal

Mol Biol Cell

PubMed ID

30354837

PubMed Central ID

PMC6340205

Authors

Adhish S Walvekar
Rajalakshmi Srinivasan
Ritu Gupta
Sunil Laxman

Keywords

Pyridoxal Phosphate
Gene Expression Regulation, Fungal
Basic-Leucine Zipper Transcription Factors
Glutamate Dehydrogenase
Glutamic Acid
Cell Proliferation
Glutamine
Saccharomyces cerevisiae
Metabolism
Saccharomyces cerevisiae Proteins
Pentose Phosphate Pathway
Nucleotides
Methionine