Hyper-O-GlcNAcylation inhibits the induction of heat shock protein 70 (Hsp 70) by sodium arsenite in HeLa cells

Biol Pharm Bull. 2014;37(8):1308-14. doi: 10.1248/bpb.b14-00170.

Abstract

O-Linked β-N-acetylglucosamine-modification (O-GlcNAcylation) is a reversible, post-translational, and regulatory modification of nuclear, mitochondrial, and cytoplasmic proteins that is responsive to cellular stress. However, the role of O-GlcNAcylation in the induction of heat shock proteins (Hsps) by arsenite remains unclear. We used O-(2-acetamido-2-deoxy-D-glucopyranosylidene) amino N-phenyl carbamate (PUGNAc), an inhibitor of O-GlcNAcase, and glucosamine (GlcN), an enhancer of the hexosamine biosynthesis pathway, or O-GlcNAc transferase (OGT) short interfering RNA (siRNA) to enhance or suppress cellular O-GlcNAcylation levels, respectively, in HeLa cells. The exposure to arsenite increased O-GlcNAcylation and Hsp 70 levels in HeLa cells. However, the pre-treatment with PUGNAc or GlcN, which enhanced O-GlcNAcylation levels, decreased the arsenite-induced expression of Hsp 70. The pre-treatment with OGT siRNA, which suppressed O-GlcNAcylation levels, did not affect the induction of Hsp 70. We then examined the effects of O-GlcNAcylation on the nuclear translocation and phosphorylation of heat shock factor 1 (HSF1), and found that neither the nuclear translocation nor phosphorylation of HSF1 was regulated by O-GlcNAcylation. Finally, Hsp 70 mRNA expression was induced by arsenite, whereas the addition of PUGNAc slightly suppressed its induction. These results indicate that O-GlcNAcylation is related to arsenite-induced Hsp 70 expression, and demonstrated that hyper-O-GlcNAcylation inhibited the induction of Hsp 70 via transcriptional factors instead of HSF1.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetylglucosamine / analogs & derivatives
  • Acetylglucosamine / pharmacology
  • Acylation
  • Arsenites / toxicity*
  • DNA-Binding Proteins / metabolism
  • Glucosamine / pharmacology
  • HSP70 Heat-Shock Proteins / genetics
  • HSP70 Heat-Shock Proteins / metabolism*
  • HeLa Cells
  • Heat Shock Transcription Factors
  • Humans
  • N-Acetylglucosaminyltransferases / antagonists & inhibitors
  • N-Acetylglucosaminyltransferases / genetics
  • N-Acetylglucosaminyltransferases / metabolism*
  • Oxidative Stress / drug effects
  • Oximes / pharmacology
  • Phenylcarbamates / pharmacology
  • Protein Processing, Post-Translational
  • RNA, Messenger / metabolism
  • RNA, Small Interfering / genetics
  • Sodium Compounds / toxicity*
  • Transcription Factors / metabolism

Substances

  • Arsenites
  • DNA-Binding Proteins
  • HSF1 protein, human
  • HSP70 Heat-Shock Proteins
  • Heat Shock Transcription Factors
  • Oximes
  • Phenylcarbamates
  • RNA, Messenger
  • RNA, Small Interfering
  • Sodium Compounds
  • Transcription Factors
  • N-acetylglucosaminono-1,5-lactone O-(phenylcarbamoyl)oxime
  • sodium arsenite
  • N-Acetylglucosaminyltransferases
  • O-GlcNAc transferase
  • Glucosamine
  • Acetylglucosamine