CAMP Response Element-Binding Protein
Introduction
The CAMP Response Element-Binding Protein (CREB) is a cellular transcription factor. It binds to certain DNA sequences called cAMP response elements (CRE), thereby increasing or decreasing the transcription of the genes. CREB was first described in 1987 as a cAMP-responsive transcription factor regulating the somatostatin gene.
Structure
CREB proteins are composed of several domains: the DNA-binding domain near the N terminus, the kinase-inducible domain (KID) and the leucine zipper domain towards the C terminus. The DNA-binding domain is 37 amino acids long and shows sequence similarity to the DNA-binding domains of other transcription factors.
Function
CREB has many functions in many different organs, and some of its functions have been studied in relation to the brain. Neurons in the brain can form new connections in response to new information. This process, known as neuroplasticity, is thought to underlie learning and memory. CREB plays a key role in the development of neuroplasticity.
Role in Memory
In the field of neuroscience, the CREB protein has been studied as a factor contributing to long-term memory (LTM) formation. CREB is necessary for the late stage of long-term potentiation. There are activator and repressor forms of CREB. Flies genetically engineered to overexpress the active form of CREB were able to remember tasks better, and for longer periods of time.
Clinical Significance
Alterations in CREB function are associated with several human conditions including cancer, diabetes, Alzheimer's disease and more. In many cancers, CREB is overexpressed and enhances survival of tumors. CREB is also thought to be involved in the growth of some types of cancer cells. In addition, it has been suggested that disruption of CREB function could lead to Alzheimer's disease.