Formaldehyde regulates <i>S</i>-adenosylmethionine biosynthesis and one-carbon metabolism.

Pham, Vanha N; Bruemmer, Kevin J; Toh, Joel D W; Ge, Eva J; Tenney, Logan; Ward, Carl C; Dingler, Felix A; Millington, Christopher L et al. · Science · 2023

basic_science · Level V

Where this comes from

Abstract

One-carbon metabolism is an essential branch of cellular metabolism that intersects with epigenetic regulation. In this work, we show how formaldehyde (FA), a one-carbon unit derived from both endogenous sources and environmental exposure, regulates one-carbon metabolism by inhibiting the biosynthesis of <i>S</i>-adenosylmethionine (SAM), the major methyl donor in cells. FA reacts with privileged, hyperreactive cysteine sites in the proteome, including Cys120 in S-adenosylmethionine synthase isoform type-1 (MAT1A). FA exposure inhibited MAT1A activity and decreased SAM production with MAT-isoform specificity. A genetic mouse model of chronic FA overload showed a decrease n SAM and in methylation on selected histones and genes. Epigenetic and transcriptional regulation of <i>Mat1a</i> and related genes function as compensatory mechanisms for FA-dependent SAM depletion, revealing a biochemical feedback cycle between FA and SAM one-carbon units.

Medical subject headings