Heat-Shock Triggers Inverted Induction of Hypo-S-Nitrosylation and Hyper-O-GlcNAcylation

Abstract

Introduction: Protein S-nitrosylation (SNO) and O-GlcNAcylation are important posttranslational modifications. The biological connection between SNO and O-GlcNAcylation is not clear.

Objective: We aim to identify the crosstalk between SNO and O-GlcNAcylation during heat-shock.

Methods: Ex vivo heat-shock on mouse tissues together with in vitro heat-shock on culture cells was performed and global levels of SNO and O-GlcNAcylation were analyzed with Biotin-switch assay (BSA) and RL2 immunoblots.

Results: Heat-shock induces hypo-SNO in parallel with hyper-O-GlcNAcylation. Inverted induction of hypo-SNO and hyper-O-GlcNAcylation is globally progressed in a time-dependent manner.

Discussion: Moreover, heat-shock ubiquitously facilitates S-denitrosylation (SdeNO) of endogenous SNO-proteins including SNO-OGT, SNO-Hsp70, SNO-Hsp90, SNO-Akt, and SNOactin. Particularly, SdeNO of SNO-OGT leads to enhanced OGT activity.

Conclusion: These findings provide mechanistic evidence that heat-shock triggers SdeNO of SNOOGT by which OGT activity is up-regulated, resulting in hyper-O-GlcNAcylation.

Keywords: N-acetylglucosaminyltransferase; O-GlcNAcylation; S-denitrosylation; S-nitrosylation; ex vivo heat-shock; in vitro heat-shock.