Ca2+/calmodulin-dependent protein kinase IV
The present invention relates to Ca 2+ /calmodulin-dependent protein kinase IV (CaMKIV) and, in particular, to methods of screening compounds for their ability to act as CaMKIV agonists or antagonists. The invention further relates to compounds identified using such methods and to therapeutic methodologies based on same.
1. A method of screening a test compound for CaMKIV agonist activity comprising:
i) contacting CaMKIV and a substrate therefor, in the presence and absence of the test compound, under conditions such that CaMKIV-dependent phosphorylation of said substrate can be effected, and
ii) determining the level of phosphorylation of said substrate resulting from step (i) and comparing said level with a level of phosphorylation of said substrate in the absence of said test compound,
wherein an increase in phosphorylation of said substrate in the presence of said test compound indicates that said test compound is a CaMKIV agonist.
2. The method according to claim 1 wherein said substrate is a peptide substrate.
3. The method according to claim 1 wherein said CaMKIV and said substrate are present in a cell free system.
4. The method according to claim 1 wherein said CaMKIV and said substrate are present in a cell.
5. The method according to claim 1 wherein, in step (i), said CaMKIV and said substrate therefor are contacted with said test compound in the presence of CaMKIV kinase, calmodulin and calcium under conditions such that CaMKIV kinase dependent phosphorylation of CaMKIV can be effected.
6. A method of screening a test compound for its activity to inhibiting differentiation of CD4+ T cells into Th2 cells comprising:
i) contacting CaMKIV and a substrate therefor in the presence of said test compound, under conditions such that CaMKIV-dependent phosphorylation of said substrate can be effected, and
ii) determining the level of phosphorylation of said substrate resulting from step (i) and comparing said level with a level of phosphorylation of said substrate obtained in the absence of said test compound,
wherein a reduction in the level of phosphorylation of said substrate in the presence of said test compound indicates that said test compound has said activity to inhibit differentiation of CD4+ T cells into Th2 cells.
7. The method according to claim 6 wherein said substrate is a peptide substrate.
8. The method according to claim 6 wherein said CaMKIV and said substrate are present in a cell free system.
9. The method according to claim 6 wherein said CaMKIV and said substrate are present in a cell.
10. The method according to claim 6 wherein, in step (i), said CaMKIV and said substrate therefor are contacted with said test compound in the presence of CaMKIV kinase, calmodulin and calcium under conditions such that CaMKIV kinase dependent phosphorylation of CaMKIV can be effected.
11. A method of screening a test compound for enhance hematopoietic cell differentiation comprising:
i) contacting CaMKIV and a substrate therefor in the presence of said test compound, under conditions such that CaMKIV-dependent phosphorylation of said substrate can be effected, and
ii) determining the level of phosphorylation of said substrate resulting from step (i) and comparing said level with a level of phosphorylation of said substrate obtained in the absence of said test compound,
wherein an increase in the level of phosphorylation of said substrate in the presence of said test compound indicates that said test compound has said activity to enhance hematopoietic cells differentiation.
12. The method according to claim 12 wherein said substrate is a peptide substrate.
13. The method according to claim 12 wherein said CaMKIV and said substrate are present in a cell free system.
14. The method according to claim 12 wherein said CaMKIV and said substrate are present in a cell.
15. The method according to claim 12 wherein, in step (i), said CaMKIV and said substrate therefor are contacted with said test compound in the presence of CaMKIV kinase, calmodulin and calcium under conditions such that CaMKIV kinase dependent phosphorylation of CaMKIV can be effected.