Abstract: Nucleic acids encoding the long form and shorter isoform of the neurotensin receptor subtype 2, referred to as HNT2R (long) and HNT2R (short), are described. Polypeptides having amino acid sequences of the HNT2R and HNT2RS isolated proteins are also provided. A method is also provided for isolating and cloning receptors expressed from the novel HNT2R and HNT2R cDNAs for use in development/implementation of high throughput screens to identify novel neurotensin agonists and antagonists. Methods are also provided for identifying compounds that bind to HNT2R.

Abstract: The present invention comprises novel recombinant DNA compounds which encode the .about.40,000 dalton adenocarcinoma antigen recognized by monoclonal antibody KS 1/4. Eukaryotic and prokaryotic expression vectors have been constructed that comprise novel KSA-encoding DNA and drive expression of KSA when transformed into an appropriate host cell. The novel expression vectors can be used to produce KSA derivatives, such as non-glycosylated KSA, and to produce KSA precursors, such as nascent KSA, and to produce subfragments of KSA. The recombinant-produced KSA is useful for the diagnosis, prognosis and treatment of disease states including adenocarcinomas of the lung, prostate, breast, ovary and colon/rectum; and for the creation of novel antibodies for treatment or diagnosis of the above.