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Published online before print May 13, 2005
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Article |
-activated STAT-1
suppresses MMP-9 gene transcription by sequestration of the coactivators CBP/p300
Department of Cell Biology, University of Alabama at Birmingham
@ To whom correspondence should be addressed. E-mail: tika{at}uab.edu.
| Abstract |
|---|
Interferon-
(IFN-
) is a pleiotropic cytokine involved in aspects of immune regulation, cell proliferation, and host defense mechanisms directed toward various cancers. Some of the biological functions of IFN-
are achieved through inhibition of gene expression, although the mechanisms by which IFN-
suppresses gene transcription are poorly understood. Herein, we demonstrate the molecular basis by which IFN-
mediates suppression of the matrix metalloproteinase-9 (MMP-9) gene. IFN-
-activated signal transducer and activator of transcription 1
(STAT-1
) suppresses MMP-9 gene transcription, which is dependent on phosphorylation of tyrosine 701 but not phosphorylation of serine 727. The coactivator cyclic AMP response element-binding protein-binding protein (CBP) is an important component of induction of MMP-9 gene transcription. IFN-
induces the in vivo association of STAT-1
and CBP and decreases the association of CBP to the MMP-9 promoter. IFN-
does not influence the stability of CBP nor does IFN-
affect chromatin-remodeling events on the MMP-9 promoter. IFN-
inhibits the assembly of the MMP-9 transcription complex by suppressing H3/H4 acetylation and inhibiting recruitment of Pol II to the MMP-9 promoter. These findings indicate that IFN-
/STAT-1
exert their inhibitory effects by affecting multiple aspects of MMP-9 gene transcription.
Key Words: cytokines transcription factors gene regulation signal transduction
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