RT Journal Article
SR Electronic
T1 Short OGA is targeted to the mitochondria and regulates mitochondrial reactive oxygen species level
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 2021.12.25.474160
DO 10.1101/2021.12.25.474160
A1 Pagesy, Patrick
A1 Bouaboud, Abdelouhab
A1 Feng, Zhihao
A1 Hulin, Philippe
A1 Issad, Tarik
YR 2021
UL http://biorxiv.org/content/early/2021/12/25/2021.12.25.474160.abstract
AB O-GlcNAcylation is a reversible post-translational modification involved the regulation of cytosolic, nuclear and mitochondrial proteins. Only two enzymes, OGT and OGA, control attachment and removal of O-GlcNAc on proteins, respectively. Whereas a variant OGT (mOGT) has been proposed as the main isoform that O-GlcNAcylates proteins in mitochondria, identification of a mitochondrial OGA has not been performed yet. Two splice variants of OGA (short and long isoforms) have been described previously. In this work, using cell fractionation experiments, we show that short-OGA is preferentially recovered in mitochondria-enriched fractions from HEK-293T cells as well as mouse embryonic fibroblasts. Moreover, fluorescent microscopy imaging confirmed that GFP-tagged short-OGA is addressed to mitochondria. In addition, using a BRET-based mitochondrial O-GlcNAcylation biosensor, we show that co-transfection of short-OGA markedly reduced O-GlcNAcylation of the biosensor, whereas long-OGA had no significant effect. Finally, using genetically encoded or chemical fluorescent mitochondrial probes, we showed that short-OGA overexpression increases mitochondrial ROS levels, whereas long-OGA had no significant effect. Together, our work reveals that the short-OGA isoform is targeted to the mitochondria where it regulates ROS homoeostasis.Competing Interest StatementThe authors have declared no competing interest.