Fig. 5.

Pharmacological evidence that DYRK1A phosphorylates S1392 and primes the phosphorylation of S1388 by GSK3β.Representative immunoblots of samples from cortical cultures treated with dimethyl sulphoxide (0.2%, Control), purvalanol (10 μM), roscovitine (20 μM) or EGCG (50 μM) and probed with pAbs against S1388-P or pS1392-P or anti-β-actin (Actin), as a loading control. Both purvalanol and EGCG increase S1388 phosphorylation, whereas roscovitine has no effect. Similarly, purvalanol and EGCG substantially reduce S1392 phosphorylation, whereas roscovitine has little effect. Histogram shows quantification of immunoblots from three or more independent experiments. Error bars are s.e.m. for three or more independent experiments. ^**P<0.01, ^***P<0.001.