Histone deacetylase-1 represses transcription by interacting with zinc-fingers and interfering with the DNA binding activity of Sp1.
Sp1 activates the transcription of many cellular and viral genes, and histone deacetylase 1 (HDAC1) removes the acetyl group of nucleosomal core histones. Treatment of cells with the histone deacetylase 1 inhibitor, TSA, robustly activates the transcription of the Sp1-dependent promoters, suggesting the inhibition of Sp1 activity which is critical in the activation of transcription, by HDAC1. We assessed the protein-protein interactions occurring between Sp1 and HDAC1, and the transcriptional regulatory mechanism controlled by this interaction. In vitro GST fusion pull down assays, co-immunoprecipitation, and mammalian two-hybrid assays revealed that the HDAC1 noncatalytic domain (a.a. 237-482) interacts directly with the zinc-finger DNA binding domain of Sp1. DNase I footprinting revealed that this interaction prevents the binding of Sp1 zinc-fingers to the target GC-box. Gal4-HDAC1 fusion, targeted proximally to the GC-boxes, potently repressed the transcription of pG5-5x(GC)-Luc, in which Sp1 potently activates transcription. This repression of transcription does not involve the deacetylase activity of HDAC1, and is accomplished by the direct protein-protein interactions which occur between the Sp1 zinc-finger DNA binding domain and HDAC1, which interferes with the promoter GC-box binding of Sp1.
Kang
Jae-Eun
JE
Department of Biochemistry and Molecular Biology, BK21 Projects for Medical Sciences, Institute of Genetic Sciences, Yonsei University School of Medicine, Seoul, Korea.
Kim
Myung-Hwa
MH
Lee
Jeong-Ahn
JA
Park
Hyejin
H
Min-Nyung
Lee
L
Auh
Chung-Koon
CK
Hur
Man-Wook
MW
D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D002460:Cell Line; D002522:Chlorocebus aethiops; D004247:DNA / Q000235:genetics / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D056572:Histone Deacetylase Inhibitors; D006655:Histone Deacetylases / Q000235:genetics / Q000378:metabolism*; D006877:Hydroxamic Acids / Q000494:pharmacology; D066298:In Vitro Techniques; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D016329:Sp1 Transcription Factor / Q000378:metabolism*; D014158:Transcription, Genetic; D020798:Two-Hybrid System Techniques; D016335:Zinc Fingers
D004791:Enzyme Inhibitors; D056572:Histone Deacetylase Inhibitors; D006877:Hydroxamic Acids; D011994:Recombinant Proteins; D016329:Sp1 Transcription Factor; C012589:trichostatin A; D004247:DNA; D006655:Histone Deacetylases