cAMP Response Element Binding Protein (CREB) is a transcription factor involved in gene expression regulation. It is a protein that binds to specific DNA sequences called cAMP response elements (CREs) in the promoter regions of target genes.
CREB is activated in response to an increase in intracellular levels of cyclic adenosine monophosphate (cAMP), a key secondary messenger molecule. Binding of cAMP to the regulatory subunit of protein kinase A (PKA) leads to the activation of PKA, which subsequently phosphorylates CREB at a specific serine residue. Phosphorylated CREB then forms a complex with the co-activator protein CBP (CREB-binding protein) or its homologue, p300, which recruits transcriptional machinery to the promoter region of target genes.
CREB plays a significant role in various cellular processes, including learning and memory, neuronal plasticity, and cellular survival. Its activation can result in the upregulation of genes involved in synaptic plasticity, long-term potentiation, and neuroprotection. Additionally, CREB has been implicated in the modulation of circadian rhythm, energy homeostasis, and neuronal development.
Dysregulation of CREB signaling has been associated with various pathological conditions, including neurodegenerative disorders, mental illnesses, cancer, and addiction. Consequently, CREB and its associated pathways have drawn considerable attention as potential targets for therapeutic interventions.
Overall, CREB is a transcription factor that serves as a crucial mediator of cAMP signaling, regulating the expression of target genes involved in numerous cellular processes and playing a pivotal role in both physiological and pathological conditions.
