Related Experiment Video
Updated: Jul 27, 2026

Focus Formation: A Cell-based Assay to Determine the Oncogenic Potential of a Gene
Published on: December 31, 2014
Smad3 is acetylated by p300/CBP to regulate its transactivation activity
1Department of Molecular Health Sciences, Graduate School of Pharmaceutical Sciences, Nagoya City University, Mizuho, Nagoya, Japan.
Abstract:
Smad proteins are crucial for the intracellular signaling of transforming growth factor-beta (TGF-beta). Upon their receptor-induced activation, Smad proteins are phosphorylated and translocated to the nucleus to activate the transcription of a select set of target genes. Here, we show that the co-activator p300/CBP bound and acetylated Smad3 as well as Smad2 in vivo, and that the acetylation was stimulated by TGF-beta. A major acetylation site of Smad3 by p300/CBP is Lys-378 in the MH2 domain (Smad3C) known to be critical for the regulation of transcriptional activity. Replacement of Lys-378 with Arg decreased the transcriptional activity of GAL4-Smad3C in a luciferase assay. Moreover, p300/CBP potentiated the transcriptional activity of GAL4-Smad3C, but not the acetylation-resistant GAL4-Smad3C(K378R) mutant. These results suggest that acetylation of Smad3 by p300/CBP regulates positively its transcriptional activity.
Related Concept Videos
Covalently Linked Protein Regulators
These groups modify specific amino acids in a protein.
Spreading of Chromatin Modifications
Writers
The writer is an enzyme that can...
Co-activators and Co-repressors
Master Transcription Regulators
Abnormal Proliferation
TGF - β Signaling Pathway

