Nucleic Acids Research, 1979, Vol. 6, No. 12 3859-3878
© 1979
Articles |
Stimulation of oligonucleotide binding of estradiol receptor complexes by accessory proteins
Division of Laboratories and Research, New York State Department of Health Albany, NY 12201, USA
To whom correspondence and reprint requests should be addressed
Received May 2, 1979.
During purification of E2R using oligo(dT)-cellulose chromatography, a receptor accessory factor (RAF) was identified in the cytoeol of mouse kidney. This factor stimulates the binding of purified E2R to oligo(dT)-, oligo(dC)-, and oligo(dA)-cellulose as well as to DNA cellulose. It is a heat-stable, trypain-resistant protein with an apparent molecular weight of between 10 and 30,000 daltons. Although structurally unrelated, similar stimulation of oligonucleotide binding was seen with calf thymus histonee and, to a lesser extent, egg white lysozyme. Individual histones, especially H2a, H2b, and H3, also facilitate rebinding of purified E2R to oligo(dT)-cellulose, while H1 is leas effective. Furthermore, histones stabilize the holoreceptor during sedimentation at 4° and 12°C. The N- and C-terminal half molecules of H2b were generated by cyanogen bromide-mediated cleavage and the N-terminal half was found to duplicate the effects of the parent molecule, both in binding and holoreceptor stabilization. These data suggest that the in vivo binding of E2R to DNA can be modulated by accessory proteins of cytosol and nuclear origin.
*Present address: Department of Obstetrics and Gynecology, College of Medicine and Dentistry of New Jersey, 100 Bergen Street, Newark, NJ 07103.