Transient downregulation of protein O-N-acetylglucosaminylation by treatment of high-dose nicotinamide in human cells.
Nicotinamide at millimolar concentrations affects cell survival in various conditions, and is being utilized therapeutically in many human diseases. However, the effect of an acute treatment of nicotinamide at such high dose on gene expression and cellular metabolism has rarely been determined previously. In this study, we found that levels of O-N-acetylglucosamin(O-GlcNAc)ylated proteins including Sp1 acutely decreased upon treatment of 10 mM nicotinamide. Concomitantly, Sp1 protein level decreased rapidly through accelerated proteasome-mediated proteolysis. Cotreatment of glucosamine or 2-deoxyglucose, which inhibits protein deGlcNAcylation, effectively blocked the decrease induced by nicotinamide. Interestingly, the decline in the levels of Sp1 and protein O- GlcNAcylation was only transient lasting for two days post treatment, and this pattern matched closely the rapid fluctuation of the cellular [NAD+]. Our results suggest a possible link between cellular nicotinamide metabolism and protein O-GlcNAcylation, and an existence of cellular [NAD+] homeostasis.
Lee
Hyung Il
HI
Department of Life Science, University of Seoul, Seoul 130-743, Korea.
Cho
Hwa Jeong
HJ
Han
Jung A
JA
Jang
So Young
SY
Wang
Kyoung Min
KM
Kang
Hyun Tae
HT
Hwan
Eun Seong
ES
D000117:Acetylglucosamine / Q000378:metabolism*; D015153:Blotting, Western; D004305:Dose-Response Relationship, Drug; D015536:Down-Regulation / Q000187:drug effects*; D006801:Humans; D006868:Hydrolysis; D009536:Niacinamide / Q000494:pharmacology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016329:Sp1 Transcription Factor / Q000378:metabolism
D016329:Sp1 Transcription Factor; D009536:Niacinamide; D000117:Acetylglucosamine