[Interaction of subunits of cAMP-dependent protein kinase with structural elements of the cell nucleus]

Using the method of protein transfer from polyacrylamide gel to nitrocellulose filters with subsequent incubation of filter-adsorbed protein with [32P]DNA, it was found that the catalytic subunit of cAMP-dependent protein kinase from porcine brain is capable of interacting with DNA to form a stable complex. This complex is resistant even to 2 M NaCl. The ability of the catalytic subunit to interact with DNA depends on the degree of enzyme nativity. The regulatory subunit of cAMP-dependent protein kinase does not bind to DNA both in the presence and absence of cAMP. The 125I-labeled regulatory subunit can interact with some chromatin proteins, in particular, with histone H1 and core histones. An essential role in this binding belongs to electrostatic and hydrophobic interactions.