Screening methods for altering circadian rhythms and for human casein kinase I δ and/or ε phosphorylation of human clock proteins, period 1, -2 and -3

A method for determining the ability of a test compound to alter phosphorylation of a human Period protein, comprising:

• (1) adding a test compound to a screening system comprising hCKI δ and/or ε protein and two or more different hPER proteins selected from the group consisting of hPER1, hPER2 and hPER3, and
• (2) determining the level of phosphorylation of human Period protein.

A method for determining the ability of a test compound to alter degradation of a human Period protein, comprising:

• (1) adding a test compound to a screening system comprising hCKI δ and/or ε protein and a hPER protein selected from the group consisting of hPER1, hPER2 and hPER3,
• (2) determining the amount of human Period protein after addition of the test compound, and
• (3) comparing the amount of human Period protein obtained in step (2) with the amount of human Period protein in the screening system.

A method for determining the ability of a test compound to alter degradation of a human Period protein, comprising:

• (1) adding a test compound and hCKI δ and/or ε protein to a screening system comprising a hPER protein selected from the group consisting of hPER1, hPER2 and hPER3,
• (2) determining the amount of human Period protein after addition of the test compound and hCKI δ and/or ε protein, and
• (3) comparing the amount of human Period protein obtained in step (2) with the amount of human Period protein in the screening system.

A method for determining the ability of a test compound to alter degradation of a human Period protein, comprising:

• (1) adding hCKI δ and/or ε protein to a screening system comprising a test compound and a hPER protein selected from the group consisting of hPER1, hPER2 and hPER3,
• (2) determining the amount of human Period protein after addition hCKI δ and/or ε protein, and
• (3) comparing the amount of human Period protein obtained in step (2) with the amount of human Period protein in the screening system.

A method for determining the ability of a test compound to alter the circadian rhythm of a mammal, comprising:

• (1) adding a test compound to a screening system comprising hCKI δ and/or ε protein and one or more human Period proteins selected from the group consisting of hPER1, hPER2 and hPER3, and
• (2) determining the effect on the circadian rhythm of the mammal relative to the circadian rhythm of the mammal in the absence of the test compound.