Absence of a putative ATP/GTP binding site in the rat prolactin receptor

Two types of the long form of the rat prolactin receptor have been identified by two independent groups. One type of receptor has a consensus sequence for a putative ATP/GTP binding site in the cytoplasmic domain, while the other does not. Since this site would confer kinase activity to the prolactin receptor and represent an important element in the process of signal transduction, we wanted to clarify this discrepancy. To that end, three procedures capable of detecting a point mutation were performed: Southern analysis of reverse transcribed polymerase chain reaction (PCR) products, allele-specific PCR, and S1 nuclease analysis. All results clearly indicated that the sequence for the putative ATP/GTP binding site does not exist in the prolactin receptor.