Skip to main content
. Author manuscript; available in PMC: 2018 Jun 5.
Published in final edited form as: Cell Rep. 2018 May 8;23(6):1651–1664. doi: 10.1016/j.celrep.2018.04.016

Figure 5. CDK5 Directly Binds to and Phos-phorylates to Activate CREB1 in GSCs.

Figure 5

(A) CP681301 treatment of mice xenografted explant culture tumors induced a clear down-regulation of CREB1 phosphorylation.

(B) Western blot data using these tumor tissues also show downregulation of CREB1 phosphorylation.

(C) We then investigated the mechanism by which CDK5 regulates CREB1. We found that Cdk5 can directly bind with CREB1, and CP681301 reduces the binding of CDK5 to CREB1.

(D) An in vitro kinase assay showed that CDK5 can phosphorylate CREB1 at serine 133, and CP681301 can suppress this phosphorylation in a dose-dependent manner.

(E) Diagram showing our proposed model where CDK5 directly phosphorylates and activates CREB1 without the requirement of cAMP/PKA in GSCs.