Photochemical attachment of cyclic AMP binding protein(s) to the nuclear genome.

The nature of the cyclic AMP-receptor-nucleus interactions was examined by a novel combination of two photoreactions. A photosensitive derivative of cyclic AMP, N6-butyryl cyclic AMP, was covalently attached to its cytoplasmic receptod by photo-affinity labelling and this receptor complex was photo-crosslinked by the DNA in the rat liver nuclei. The photolytic reactions seemed to be specific since stable links were formed only when substantial noncovalent binding occured.