Identifying parathyroid hormone agonists and antagonists

A method of screening for an agent that is a parathyroid hormone (PTH) agonist, the method comprising:

• (a) contacting a cell with a parathyroid hormone (PTH) polypeptide or a receptor-binding fragment thereof, a WNT polypeptide or fragment thereof, and the agent to be screened, wherein the cell comprises a parathyroid hormone 1 receptor (PTH1R) and a nucleotide sequence encoding a reporter protein operably linked to an inducible promoter, wherein the inducible promoter is activated by PTH1R;
• and
• (b) determining a level of reporter protein expression, an increased level of reporter protein expression as compared to a control indicating the agent is a PTH agonist.

(canceled)

(canceled)

(canceled)

(canceled)

A method of screening for an agent that is a parathyroid hormone (PTH) antagonist, the method comprising:

• (a) contacting a cell with parathyroid hormone (PTH) polypeptide or a receptor-binding fragment thereof, a WNT polypeptide or fragment thereof, and the agent to be screened, wherein the cell comprises a parathyroid hormone 1 receptor (PTH1R) and a nucleotide sequence encoding a reporter protein operably linked to an inducible promoter, wherein the inducible promoter is activated by PTH1R;
• and
• (b) determining a level of reporter protein expression, a decreased level of reporter protein expression as compared to a control indicating the agent is a PTH antagonist.

(canceled)

(canceled)

(canceled)

(canceled)

A method of screening for an agent that is a parathyroid hormone (PTH) agonist, the method comprising:

• (a) contacting a cell with a parathyroid hormone (PTH) polypeptide or a receptor-binding fragment thereof, a WNT polypeptide or fragment thereof, and the agent to be screened, wherein the cell comprises a parathyroid hormone 1 receptor (PTH1R);
• and
• (b) determining a level of secreted osteosclerostin polypeptide, an increased level of osteosclerostin as compared to a control indicating that the agent is a PTH agonist.

(canceled)

(canceled)

A method of screening for an agent that is a parathyroid hormone (PTH) antagonist, the method comprising:

• (a) contacting a cell with a parathyroid hormone (PTH) polypeptide or a receptor-binding fragment thereof, a WNT polypeptide or fragment thereof, and the agent to be screened, wherein the cell comprises a parathyroid hormone 1 receptor (PTH1R);
• and
• (b) determining a level of secreted osteosclerostin polypeptide, a decreased level of osteosclerostin as compared to a control indicating that the agent is a PTH antagonist.

(canceled)

(canceled)