THE DNA-BINDING AFFINITY OF RAT-LIVER NUCLEOPROTEINS TO THE REGULATORY ELEMENTS OF THE HAPTOGLOBIN AND ALPHA(2)-MACROGLOBULIN GENES

Transcriptional regulation and binding interactions between soluble nu cleoproteins and the hormone response elements (REs) of the rat haptog lobin (Hp) and alpha(2)-macroglobulin (alpha(2)MG) genes was examined in the livers of rats during the acute-phase reaction. Our results dem onstrate that the elevation of the Hp and alpha(2)MG genes' transcript ion rates in acute-phase liver relies essentially on an increase in th e binding-affinity of pre-xisting soluble nucleoproteins, enhancing th eir capability to bind the examined cis-regulatory elements. The 35kD nucleoprotein that displayed an acute-phase inducible affinity to bind hormone REs of rat Hp and (alpha(2)MG genes, was identified as a C/EB P beta isoform.