Vector modified by sequence coding for a sequence of amino acids contained in a mammalian protein having the biological activity of a membrane receptor, expression of this sequence in transformed unicellular cultures by means of this vector, procedure for studying ligands recognizing these receptors

A yeast cell stably transformed with an expression vector comprising:

• (a) an insert encoding a polypeptide of a mammalian receptor selected from the group consisting of β-adrenergic receptors and serotonin receptors;
• and
• (b) a control region capable of being recognized by polymerases of the yeast cell for expression of said polypeptide in said yeast, wherein said control region comprises a signal sequence;
• and
• wherein, after expression, said polypeptide is incorporated into the cell membrane of said yeast cell and said polypeptide is capable of binding a ligand of said mammalian receptor.

A yeast cell stably transformed with an expression vector comprising:

• (a) an insert encoding a mammalian receptor comprising seven hydrophobic transmembrane segments, extracellular and intracellular loops, an extracellular amino terminal region, and a carboxyl terminal cytoplasmic region;
• and
• (b) a control region capable of being recognized by polymerases of the yeast cell for expression of said polypeptide in said yeast cell;
• and
• wherein, after expression, said polypeptide is incorporated into a cell membrane of said yeast cell and said polypeptide is capable of binding a ligand of said mammalian receptor.

A yeast cell stably transformed with an expression vector comprising:

• (a) an insert encoding a polypeptide of a mammalian receptor selected from the group consisting of β-adrenergic receptors and serotonin receptors;
• and
• (b) a control region capable of being recognized by polymerases of the yeast cell for expression of said polypeptide in said yeast cell;
• and
• wherein, after expression, said polypeptide is incorporated into a cell membrane of said yeast cell and said polypeptide is capable of binding a ligand of said mammalian receptor.