Abstract: Described are methods of detecting G-protein coupled receptor (GPCR) activity in vivo and in vitro; methods of assaying GPCR activity; and methods of screening for GPCR ligands, G protein-coupled receptor kinase (GRK) activity, and compounds that interact with components of the GPCR regulatory process. Constructs useful in such methods are described.

Abstract: A method of treating a subject for a serotonergic neurotransmission dysregulation disorder, comprises administering the subject a serotonin enhancer (e.g., a serotonin reuptake inhibitor) in an amount effective to treat the disorder; and concurrently administering the subject 5-hydroxytryptophan in an amount effective to enhance the activity of the serotonin enhancer, (e.g., serotonin reuptake inhibitor). In preferred embodiments the disorder is depression, anxiety, or substance abuse.

Abstract: The present invention is related to the detection of GPCR ligands in a test sample by using a single cell biosensor expressing a GPCR. Preferably, the test sample is derived from a biological or environmental sample. This invention may be used to detect the presence of a disease or to detect the presence of a harmful agent in the environment. Included in the present invention is an array of biosensors that detect ligands of various GPCRs.

Abstract: A method of treating a subject for a serotonergic neurotransmission dysregulation disorder, comprises administering the subject a serotonin enhancer (e.g., a serotonin reuptake inhibitor) in an amount effective to treat the disorder; and concurrently administering the subject 5-hydroxytryptophan in an amount effective to enhance the activity of the serotonin enahancer, (e.g., serotonin reuptake inhibitor). In preferred embodiments the disorder is depression, anxiety, or substance abuse.

Abstract: The present invention is related to the detection of GPCR ligands in a test sample by using a single cell biosensor expressing a GPCR. Preferably, the test sample is derived from a biological or environmental sample. This invention may be used to detect the presence of a disease or to detect the presence of a harmful agent in the environment. Included in the present invention is an array of biosensors that detect ligands of various GPCRs.

Abstract: Described are methods of detecting G-protein coupled receptor (GPCR) activity in vivo and in vitro; methods of assaying GPCR activity; and methods of screening for GPCR ligands, G protein-coupled receptor kinase (GRK) activity, and compounds that interact with components of the GPCR regulatory process. Constructs useful in such methods are described.

Abstract: Disclosed is a transformed yeast cell containing a first heterologous DNA sequence which codes for a mammalian G protein-coupled receptor and a second heterologous DNA sequence which codes for a mammalian G protein ? subunit (mammalian G?). The first and second heterologous DNA sequences are capable of expression in the cell, but the cell is incapable of expressing an endogenous G protein ?-subunit (yeast G?). The cells are useful for screening compounds which affect the rate of dissociation of G? from G?? in a cell. Also disclosed is a novel DNA expression vector useful for making cells as described above. The vector contains a first segment comprising at least a fragment of the extreme amino-terminal coding sequence of a yeast G protein-coupled receptor. A second segment is positioned downstream from the first segment (and in correct reading frame therewith), with the second segment comprising a DNA sequence encoding a heterologous G protein-coupled receptor.

Abstract: The present invention relates to modified G-protein coupled receptors (GPCRs). The modified GPCRs of the present invention include GPCRs that have been modified to have altered DRY motifs such that the modified GPCRs are constitutively desensitized. As such, the modified GPCRs of the present invention preferably localize to endocytic vesicles or endosomes in an agonist-independent manner. The invention also relates to methods of screening compounds and sample solutions for GPCR activity using the modified GPCRs.

Abstract: The present invention relates to modified G-protein coupled receptors (GPCRs). The modified GPCRs of the present invention include GPCRs that have been modified to have carboxyl terminal tails comprising one or more sites of phosphorylation, preferably one or more clusters of phosphorylation sites. The modified GPCRs of the present invention may comprise a retained portion of a carboxyl-terminus region from a first GPCR fused to a polypeptide, wherein the polypeptide comprises the one or more clusters of phosphorylation. The present invention also relates to methods of screening compounds and sample solutions for GPCR activity using the modified GPCRs.

Abstract: The methods of the present invention allow the screening of a test composition for non-receptor-specific GPCR desensitization inhibitory activity. The methods involve screening a test composition for an indication of GPCR desensitization inhibitory activity against two or more GPCRs that are different from each other. When there is an indication that a particular test composition has GPCR desensitization inhibitory activity with respect to each of the two or more GPCRs that are different from one another, then, according to the present invention, there is an indication that the test composition has non-receptor-specific GPCR desensitization inhibitory activity.

Abstract: Described are methods of detecting G-protein coupled receptor (GPCR) activity in vivo and in vitro; methods of assaying GPCR activity; and methods of screening for GPCR ligands, G Protein-coupled receptor kinase (GRK) activity, and compounds that interact with components of the GPCR regulatory process.

Abstract: The present invention relates to modified G-protein coupled receptors (GPCRs). The modified GPCRs of the present invention include GPCRs that have been modified to have carboxyl terminal tails comprising one or more sites of phosphorylation, preferably one or more clusters of phosphorylation sites. The modified GPCRs of the present invention may comprise a retained portion of a carboxyl-terminus region from a first GPCR fused to a polypeptide, wherein the polypeptide comprises the one or more clusters of phosphorylation. The present invention also relates to methods of screening compounds and sample solutions for GPCR activity using the modified GPCRs.

Abstract: Disclosed is a transformed yeast cell containing a first heterologous DNA sequence which codes for a mammalian G protean coupled receptor and a second heterologous DNA sequence which codes for a mammalian G protein ? subunit (mammalian G?). The first and second heterologous DNA sequences are capable of expression in the cell, but the cell is incapable of expressing an endogenous G protein ?-subunit (yeast G?). The cells are useful for screening compounds which affect the rate of dissociation of G? from G?? in a cell. Also disclosed is a novel DNA expression vector useful for making cells as described above. The vector contains a first segment comprising at least a fragment of the extreme amino-terminal coding sequence of a yeast G protein coupled receptor. A second segment is positioned downstream from the first segment (and in correct reading frame therewith), with the second segment comprising a DNA sequence encoding a heterologous G protein coupled receptor.

Abstract: Described are methods of detecting G-protein coupled receptor (GPCR) activity in vivo and in vitro; methods of assaying GPCR activity; and methods of screening for GPCR ligands, G protein-coupled receptor kinase (GRK) activity, and compounds that interact with components of the GPCR regulatory process. Constructs useful in such methods are described.

Abstract: Described are methods of detecting G-protein coupled receptor (GPCR) activity in vivo and in vitro; methods of assaying GPCR activity; and methods of screening for GPCR ligands, G protein-coupled receptor kinase (GRK) activity, and compounds that interact with components of the GPCR regulatory process. Constructs useful in such methods are described.

Abstract: Described are methods of detecting G-protein coupled receptor (GPCR) activity in vivo and in vitro; methods of assaying GPCR activity; and methods of screening for GPCR ligands, G protein-coupled receptor kinase (GRK) activity and compounds that interact with components of the GPCR regulatory process. Constructs useful in such methods are described.

Abstract: The methods of the present invention allow the screening of a test composition for non-receptor-specific GPCR desensitization inhibitory activity. The methods involve screening a test composition for an indication of GPCR desensitization inhibitory activity against two or more GPCRs that are different from each other. When there is an indication that a particular test composition has GPCR desensitization inhibitory activity with respect to each of the two or more GPCRs that are different from one another, then, according to the present invention, there is an indication that the test composition has non-receptor-specific GPCR desensitization inhibitory activity.

Abstract: The present invention relates to a method of inhibiting desensitization of a cell to the effects of a compound. The method comprises contacting the cell with an agent capable of inhibiting phosphorylation, by a protein kinase, of a receptor for the compound present on the surface of the cell. The present invention also relates to a method of screening a compound for its ability to inhibit desensitization.

Abstract: Disclosed is a transformed yeast cell containing a first heterologous DNA sequence which codes for a mammalian G protein coupled receptor and a second heterologous DNA sequence which codes for a mammalian G protein a subunit (mammalian G&agr;). The first and second heterologous DNA sequences are capable of expression in the cell, but the cell is incapable of expressing an endogenous G protein &agr;-subunit (yeast G&agr;). The cells are useful for screening compounds which affect the rate of dissociation of G&agr; from G&bgr;&tgr; in a cell.

Abstract: The present invention relates to compounds that alter GPCR internalization and new methods for their identification. Compounds of this invention include modified phosphoinositide 3-kinase (PI3K), modified HEAT domain, modified &bgr;-adrenergic receptor kinase 1 (&bgr;ARK1), as well as other peptides or small molecules that alter GPCR internalization. The present invention also includes the use of such compounds to treat GPCR-related diseases, such as cardiovascular disease, heart failure, asthma, nephrogenic diabetes insipidus, or hypertension.