1-Azakenpaullone

GSK-3β is assayed, following a 1/100 dilution in 1 mg BSA per mL 10 mM dithiothreitol, with 5 μL 40 μM GS-1 peptide as a substrate, in buffer A, in the presence of 15 μM [γ-³²P]ATP (3000 Ci·mmol^-1; 1 mCi·mL^-1 ) in a final volume of 30 μL. After 30 min incubation at 30℃, 25 μL aliquots of supernatant are spotted onto 2.5×3 cm pieces of Whatman P81 phosphocellulose paper, and 20 s later, the filters are washed five times in a solution of 10 mL phosphoric acid per L of water. The wet filters are counted in the presence of 1 mL ACS scintillation fluid. The kinase activity of CDK1/cyclin B is assayed in buffer C, with 1 mg/mL histone H1, in the presence of 15 μM [γ-32P]ATP (3000 Ci·mmol^-1; 1 mCi·mL^-1 ) in a final volume of 30 μL. After 10 min incubation at 30℃, 25 μL aliquots of supernatant are spotted onto P81 phosphocellulose papers and treated as described above. The activity of CDK5/p25 is assayed in buffer C as described for CDK1/cyclin B. (Buffer A: 10 mM MgCl2 , 1 mM EGTA, 1 mM dithiothreitol, 25 mM Tris/HCl pH 7.5, 50 μg heparin/mL. Buffer C: homogenization buffer but 5 mM EGTA, no NaF and no protease inhibitors.)

INS-1E β cell

20 μM

4 days

Cell replication is determined by BrdUrd incorporation after treatment with 1-Azakenpaullone for 24 h. The relative cell number is determined after treatment with 1-Azakenpaullone for 4 days using the CyQuant cell proliferation assay. Results are presented as fold change relative to control.

Male NMRI mice

~500 pmol

i.c.v.