I. Grigorov et al., ACUTE-PHASE INDUCED PHOSPHORYLATION OF RAT-LIVER NUCLEOPROTEIN P70 MODULATES ITS BINDING-AFFINITY FOR THE HAPTOGLOBIN GENE, Biochemistry and molecular biology international, 45(5), 1998, pp. 1067-1072
An increase in the binding affinity of rat liver trans-acting nucleopr
otein p70 for the hormone responsive element of the rat haptoglobin ge
ne in acute-phase reactions has implicated a posttranslational modific
ation. This investigation examines the proposed acute-phase related st
ructural alterations of p70 using an in vitro phosphorylation/dephosph
orylation assay and selective digestion of p70 with Staphylococcal aur
eus V8 protease. The results show that p70 requires phosphorylation to
express its DNA-binding ability. Selective proteolysis of p70 provide
d evidence that acute-phase induced phosphorylation of this protein al
ters its conformation in such a way that its DNA-binding ability is in
creased.