Interferon regulatory factor-2 regulates cell growth through its acetylation.
We have previously shown that interferon regulatory factor-2 (IRF-2) is acetylated by p300 and PCAF in vivo and in vitro. In this study we identified, by mass spectrometry, two lysine residues in the DNA binding domain (DBD), Lys-75 and Lys-78, to be the major acetylation sites in IRF-2. Although acetylation of IRF-2 did not alter DNA binding activity in vitro, mutation of Lys-75 diminished the IRF-2-dependent activation of histone H4 promoter activity. Acetylation of IRF-2 and IRF-2-stimulated H4 promoter activity were inhibited by the adenovirus E1A, indicating the involvement of p300/CBP. Mutation of Lys-78, a residue conserved throughout the IRF family members, led to the abrogation of DNA binding activity independently of acetylation. H4 is transcribed only in rapidly growing cells and its promoter activity is dependent on cell growth. Consistent with a role for acetylated IRF-2 in cell growth control, IRF-2 was acetylated only in growing NIH 3T3 cells, but not in growth-arrested counterparts. Chromatin immunoprecipitation assays showed that IRF-2 interacted with p300 and bound to the endogenous H4 promoter only in growing cells, although the levels of total IRF-2 were comparable in both growing and growth-arrested cells. These results indicate that IRF-2 is acetylated in a cell growth-dependent manner, which enables it to contribute to transcription of cell growth-regulated promoters.
Masumi
Atsuko
A
Department of Safety Research on Biologics, National Institute of Infectious Diseases, Tokyo, Japan. amasumi@nih.go.jp
Yamakawa
Yoshio
Y
Fukazawa
Hidesuke
H
Ozato
Keiko
K
Komuro
Katsutoshi
K
D016475:3T3 Cells; D000107:Acetylation; D000595:Amino Acid Sequence; D000818:Animals; D015153:Blotting, Western; D002455:Cell Division; D002843:Chromatin / Q000378:metabolism; D004247:DNA / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000502:physiology*; D005982:Glutathione Transferase / Q000378:metabolism; D006657:Histones / Q000235:genetics; D050836:Interferon Regulatory Factor-2; D008239:Lysine / Q000737:chemistry; D013058:Mass Spectrometry; D051379:Mice; D008969:Molecular Sequence Data; D009154:Mutation; D010957:Plasmids / Q000378:metabolism; D011233:Precipitin Tests; D011401:Promoter Regions, Genetic; D017434:Protein Structure, Tertiary; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012097:Repressor Proteins; D014157:Transcription Factors; D014162:Transfection
D002843:Chromatin; D004268:DNA-Binding Proteins; D006657:Histones; D050836:Interferon Regulatory Factor-2; C494230:Irf2 protein, mouse; D011993:Recombinant Fusion Proteins; D012097:Repressor Proteins; D014157:Transcription Factors; D004247:DNA; D005982:Glutathione Transferase; D008239:Lysine