Page "CREB" Paragraph 15

A typical ( albeit somewhat simplified ) sequence of events is as follows: A signal arrives at the cell surface, activates the corresponding receptor, which leads to the production of a second messenger such as cAMP or Ca < sup > 2 +</ sup >, which in turn activates a protein kinase.

This protein kinase translocates to the cell nucleus, where it activates a CREB protein.

The activated CREB protein then binds to a CRE region, and is then bound to by a CBP ( CREB-binding protein ), which coactivates it, allowing it to switch certain genes on or off.

The DNA binding of CREB is mediated via its basic leucine zipper domain ( bZIP domain ) as depicted in the photograph.