Figure 1.

cAMP-response element binding protein (CREB) Regulation. CREB is a well-studied TF that exemplifies the complexity of TF-PTM regulatory circuits. Canonical CREB regulation begins with phosphorylation of Ser133 by Protein Kinase A (PKA), which facilitates interaction with CREB-binding protein (CBP) to recruit RNA Polymerase II (RNAPII) and promote transcription of target genes such as Somatostatin (SST). Other kinases can also regulate CREB through Ser133 and other phosphorylations, CBP can further regulate CREB activity through multiple acetylations, and glycosylation can disrupt the activating effect of the Ser133 phosphorylation.