Abstract: Cloned genes which code for the D.sub.1 dopamine receptor are disclosed. The receptors coded for by these clones bind dopamine ligands with the proper pharmacological profile and, when expressed in the cell membrane of a suitable host and so bound, stimulate adenylyl cyclase. Also disclosed are vectors comprising a cloned gene encoding a D.sub.1 -dopamine receptor, cells transformed with such vectors, and oligonucleotide probes capable of selectively hybridizing to DNA comprising a portion of a gene coding for a D.sub.1 -dopamine receptor. The cloned genes are useful for making proteins and cell membrane preparations which can be used to screen compounds for D.sub.1 -dopamine receptor binding activity, are useful in molecular biology, and are useful as diagnostic probes.