Acute-phase induced phosphorylation of rat liver nucleoprotein p70 modulates its binding affinity for the haptoglobin gene.
An increase in the binding affinity of rat liver trans-acting nucleoprotein p70 for the hormone responsive element of the rat haptoglobin gene in acute-phase reactions has implicated a posttranslational modification. This investigation examines the proposed acute-phase related structural alterations of p70 using an in vitro phosphorylation/dephosphorylation assay and selective digestion of p70 with Staphylococcal aureus V8 protease. The results show that p70 requires phosphorylation to express its DNA-binding ability. Selective proteolysis of p70 provided evidence that acute-phase induced phosphorylation of this protein alters its conformation in such a way that its DNA-binding ability is increased.
Grigorov
I
I
Molecular Biology Laboratory, Institute for Biological Research, Belgrade, Yugoslav Federal Republic.
Milosavljević
T
T
Petrović
M
M
D000210:Acute-Phase Reaction; D000818:Animals; D004247:DNA / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000378:metabolism*; D006242:Haptoglobins / Q000235:genetics*; D008297:Male; D009687:Nuclear Proteins / Q000378:metabolism*; D010766:Phosphorylation; D051381:Rats; D017208:Rats, Wistar; D020218:Response Elements
D004268:DNA-Binding Proteins; D006242:Haptoglobins; D009687:Nuclear Proteins; D004247:DNA