Nuclear GTPSCS functions as a lactyl-CoA synthetase to promote histone lactylation and glioma progression [RNA-Seq]
Histone lysine lactylation is a physiologically relevant epigenetic pathway that can be stimulated by the Warburg effect and L-lactate. Nevertheless, the mechanism by which cells use L-lactate to generate lactyl-CoA, the cofactor for the modification, and how this process is regulated remain unknown. Here we report identification of GTPSCS as a robust lactyl-CoA synthetase using biochemistry and cell biology approaches. The mechanism of this catalytic activity was elucidated using the crystallographic structure of GTPSCS in complex with L-lactate, followed by mutagenesis experiments. GTPSCS translocates into the nucleus and interacts with p300 to form a functional lactyltransferase to elevate histone lactylation, but not histone succinylation. This process is dependent on not only a nuclear localization signal in the GTPSCS G1 subunit, but also acetylation at G2 subunit residue K73 which mediates the interaction with p300. GTPSCS-p300 collaboration synergistically regulates histone H3K18la, subsequently enhancing the expression of GDF15. This process promotes the proliferation of glioma cells and facilitates tumor formation in mice. In addition, GTPSCS is upregulated in glioma and correlates with glioma malignancy, while histone H3K18la, and GDF15 levels are positively associated with glioma malignancy and poor prognosis in GBM patients. The GTPSCS-lactyltransferase-histone Kla axis thus represents an epigenetic pathway linking lactate metabolism with an oncogenic gene expression pattern in glioma. Overall design: We carried out RNA-Seq analyses in either patient-derived SUCLG1-depleted rSUCLG1 WT UTSW63 cells or its rSUCLG1 K192R mutant counterpart.