Abstract: The present invention provides for a substantially pure human or rabbit 3-phosphoinositide-dependent protein kinase.

Abstract: The use of a polypeptide capable of binding to PtdIns(3,4)P2, PtdIns3P, PtdIns4P or PtdIns(3,5)P2 but not capable of binding to PtdIns(3,4,5)P3, in a screening method for identifying a compound suitable for modulating signalling by PtdIns(3,4)P2, PtdIns3P, PtdIns4P or PtdIns(3,5)P2. The polypeptide preferably comprises a PH domain which binds specifically to one of PtdIns(3,4)P2, PtdIns3P, PtdIns4P or PtdIns(3,5)P2. The PH−domain preferably has at least five of the six residues of a PutativePtdIns(3,4,5)P3 Binding Motif (PPBM).

Abstract: A method of identifying a compound that modulates the protein kinase activity of a protein kinase having a hydrophobic pocket in the position equivalent to the hydrophobic pocket of Protein Kinase A (PKA) that is defined by residues including Lys76, Leu116, Val80 and/or Lys111 of full-length mouse PKA, wherein the ability of the compound to inhibit, promote or mimic the interaction of the said hydrophobic pocket-containing protein kinase with an interacting polypeptide is measured and a compound that inhibits, promotes or mimics the said interaction interacts is selected, wherein the interacting polypeptide with the hydrophobic pocket of the protein kinase and/or comprises the amino acid sequence Phe/Tyr-Xaa-Xaa-Phe/Tyr.

Abstract: A method for screening for agents capable of affecting the activity of kinases GSK3 and PKB is disclosed. The method involves assessing the phosphorylation of PKB on two amino acids on the PKB molecule particularly.