Abstract

Avian oviduct progesterone receptor was treated with the 2',3'-dialdehyde derivative of ATP (oATP) in an attempt to demonstrate the presence of nucleotide binding sites on the receptor. oATP, when added to cytosol, inhibited binding by transformed receptor to ATP-Sepharose, DNA-cellulose, phosphocellulose, or isolated nuclei in an irreversible manner. oATP did not disrupt the steroid-receptor complex, but it did alter the ionic properties of the receptor. This was demonstrated by an increased affinity of receptor for DEAE-cellulose and for hydroxylapatite. oATP mimicked the effect of ATP on progesterone receptor with regard to two properties: it altered the rate of receptor inactivation that occurs in the absence of progesterone, and it promoted receptor conversion from an 8S complex to lower sedimenting forms (4-6 S). The action of oATP on the receptor could be blocked by the addition of pyridoxal 5'-phosphate, which has been shown previously to interact with the progesterone receptor. A partial interference of oATP action was also observed when ATP was added. These results indicate that oATP interacts with the progesterone receptor and may be used as an affinity-labeling agent for receptor characterization.

Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call