The BioGRID | PUBLICATION VIEW

	J. Biol. Chem. Apr (1998); 273(17):10784-91
Identification of heterogeneous nuclear ribonucleoprotein K (hnRNP K) as a repressor of C/EBPbeta-mediated gene activation.
Miau LH, Chang CJ, Shen BJ, Tsai WH, Lee SC
Institute of Molecular Medicine, Dr. H.-L. Tsai Memorial Laboratory, College of Medicine, National Taiwan University, Taipei, Taiwan.
Abstract: Transcription factor C/EBPbeta has been known to regulate a wide array of genes including those involved in the acute-phase response. One of the molecular mechanisms underlying transcription activation by C/EBPbeta is through protein-protein interaction with other transcription factors. Here we report the identification and characterization of physical and functional interactions between C/EBPbeta and heterogeneous nuclear ribonucleoprotein (hnRNP) K. This interaction results in the repression of C/EBPbeta-dependent trans-activation of the agp gene. Footprinting assays indicate that hnRNP K cannot bind to the promoter region of agp gene or interfere with the binding of C/EBPbeta to its cognate DNA site. Furthermore, agp gene activation by the synergistic interaction of Nopp140 and C/EBPbeta is abolished by hnRNP K. The kinetics of appearance of C/EBPbeta-hnRNP K complex in the nuclear extract after initiation of acute-phase reaction indicates that hnRNP K functions as a negative regulator of C/EBPbeta-mediated activation of agp gene.
[PUBMED: 9553145]