Fig. 2

Analysis of CRMP and tau phosphorylation by CDK5 in vitro. Recombinant protein substrates (0.5 μM final concentration) were incubated with 2mUnits of each CDK5 complex and MgCl2 and [γ-32P] ATP (approx 0.5x10⁶ CPM/nmole) for 30 mins. Reactions were terminated by the addition of SDS-PAGE loading buffer and heating to 70 °C. Aliquots were subjected to SDS-PAGE, stained with Coomassie Brilliant Blue (CBR-250), the gels were dried and radiolabeled bands visualized by autoradiography. a Comparison of CRMP-1, −2 and −4 (wild-type and Ser522Ala mutants) phosphorylation by each CDK5 complex. b GST-tau (0.5 μM final concentration) was incubated with 2mUnits of each CDK5 complex for 30 min, with or without a 30 min pre-incubation with the Cdk inhibitors roscovitine (10 μM) or purvalanol A (10 μM). Data is representative of at least three different experiments