OGT functions as a catalytic chaperone under heat stress response: a unique defense role of OGT in hyperthermia.
Protein O-GlcNAcylation is proceeded by O-linked GlcNAc transferase (OGT) in nucleocytoplasm and is involved in many biological processes although its physiological role is not clearly defined. To identify the functional significance of O-GlcNAcylation, we investigated heat stress effects on protein O-GlcNAcylation. Here, we found that protein O-GlcNAcylation was significantly increased in vivo during acute heat stress in mammalian cells and simultaneously, the enhanced protein O-GlcNAcylation was closely associated with cell survival in hyperthermia. Our results demonstrate that hyperthermal cytotoxicity may considerably be facilitated under the condition of insufficient level of protein O-GlcNAcylation inside cells. Furthermore, OGT reaction might be crucial for triggering thermotolerance to recover hyperthermal sensitivity without particular induction of heat shock proteins (hsps). Thus, we propose that OGT can respond rapidly to heat stress through the enhancement of nucleocytoplasmic protein O-GlcNAcylation for a rescue from the early phase of hyperthermal cytotoxicity.
Sohn
Kyung-Cheol
KC
Chungnam National University, School of Bioscience and Biotechnology, Taejon 305-764, Republic of Korea.
Lee
Ki-Young
KY
Park
Jae Eun
JE
Do
Su-Il
SI
D000215:Acylation; D000818:Animals; D016466:CHO Cells; D006528:Carcinoma, Hepatocellular; D045744:Cell Line, Tumor; D002467:Cell Nucleus / Q000201:enzymology; D006224:Cricetinae; D003593:Cytoplasm / Q000201:enzymology; D006358:Hot Temperature; D006801:Humans; D007700:Kinetics; D008113:Liver Neoplasms; D017351:N-Acetylglucosaminyltransferases / Q000235:genetics* / Q000378:metabolism*; D011994:Recombinant Proteins / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013816:Thermodynamics
D011994:Recombinant Proteins; D017351:N-Acetylglucosaminyltransferases; C063057:UDP-N-acetylglucosamine-peptide beta-N-acetylglucosaminyltransferase