O-linked N-acetylglucosamine suppresses thermal aggregation of Sp1.
We demonstrate that O-linked N-acetylglucosamine (O-GlcNAc), a ubiquitous protein modification in eukaryotes, suppresses thermal inactivation of Sp1 transcription factor. 6-Diazo-5-oxonorleucine treatment or O-GlcNAcase overexpression, which reduced O-GlcNAc levels on Sp1, deteriorated thermal stability of Sp1 and O-GlcNAc modified molecules of Sp1 resist thermal aggregation in vitro. We also showed that heat-induced elevation of heat shock protein 70 was facilitated by Sp1 but blunted under low O-GlcNAc levels, suggesting that O-GlcNAc might upregulate the expression of heat shock protein 70 through thermoprotection of Sp1, which eventually enhanced cellular thermotolerance.
Lim
Ki-Hong
KH
School of Life Sciences and Biotechnology, Korea University, 5-1 Anam-dong, Seongbuk-gu, Seoul 136-701, Republic of Korea.
Chang
Hyo-Ihl
HI
D000117:Acetylglucosamine / Q000737:chemistry / Q000378:metabolism*; D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D017931:DNA Primers; D006801:Humans; D016329:Sp1 Transcription Factor / Q000378:metabolism*; D013696:Temperature
D017931:DNA Primers; D016329:Sp1 Transcription Factor; D000117:Acetylglucosamine