TY - JOUR
T1 - O-linked N-acetylglucosamine modification on CCAAT enhancer-binding protein β. Role during adipocyte differentiation
AU - Li, Xi
AU - Molina, Henrik
AU - Huang, Haiyan
AU - Zhang, You You
AU - Liu, Mei
AU - Qian, Shu Wen
AU - Slawson, Chad
AU - Dias, Wagner B.
AU - Pandey, Akhilesh
AU - Hart, Gerald W.
AU - Lane, M. Daniel
AU - Tang, Qi Qun
PY - 2009/7/17
Y1 - 2009/7/17
N2 - CCAAT enhancer-binding protein (C/EBP)β is a basic leucine zipper transcription factor family member, and can be phosphorylated, acetylated, and sumoylated. C/EBPβ undergoes sequential phosphorylation during 3T3-L1 adipocyte differentiation. Phosphorylation on Thr188 by MAPK or cyclin A/cdk2 primes the phosphorylations on Ser184/Thr179 by GSK3β, and these phosphorylations are required for the acquisition of DNA binding activity of C/EBPβ. Here we show that C/EBPβ is modified by O-GlcNAc, a dynamic single sugar modification found on nucleocytoplasmic proteins. The GlcNAcylation sites are Ser180 and Ser181, which are in the regulation domain and are very close to the phosphorylation sites (Thr188, Ser184, and Thr179) required for the gain of DNA binding activity. Both in vitro and ex vivo experiments demonstrate that GlcNAcylation on Ser180 and Ser181 prevents phosphorylation on Thr188, Ser184, and Thr179, as indicated by the decreased relative phosphorylation and DNA binding activity of C/EBPβ delayed the adipocyte differentiation program. Mutation of both Ser180 and Ser181 to Ala significantly increase the transcriptional activity of C/EBPβ. These data suggest that GlcNAcylation regulates both the phosphorylation and DNA binding activity of C/EBPβ.
AB - CCAAT enhancer-binding protein (C/EBP)β is a basic leucine zipper transcription factor family member, and can be phosphorylated, acetylated, and sumoylated. C/EBPβ undergoes sequential phosphorylation during 3T3-L1 adipocyte differentiation. Phosphorylation on Thr188 by MAPK or cyclin A/cdk2 primes the phosphorylations on Ser184/Thr179 by GSK3β, and these phosphorylations are required for the acquisition of DNA binding activity of C/EBPβ. Here we show that C/EBPβ is modified by O-GlcNAc, a dynamic single sugar modification found on nucleocytoplasmic proteins. The GlcNAcylation sites are Ser180 and Ser181, which are in the regulation domain and are very close to the phosphorylation sites (Thr188, Ser184, and Thr179) required for the gain of DNA binding activity. Both in vitro and ex vivo experiments demonstrate that GlcNAcylation on Ser180 and Ser181 prevents phosphorylation on Thr188, Ser184, and Thr179, as indicated by the decreased relative phosphorylation and DNA binding activity of C/EBPβ delayed the adipocyte differentiation program. Mutation of both Ser180 and Ser181 to Ala significantly increase the transcriptional activity of C/EBPβ. These data suggest that GlcNAcylation regulates both the phosphorylation and DNA binding activity of C/EBPβ.
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U2 - 10.1074/jbc.M109.005678
DO - 10.1074/jbc.M109.005678
M3 - Article
C2 - 19478079
AN - SCOPUS:67749099837
SN - 0021-9258
VL - 284
SP - 19248
EP - 19254
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 29
ER -