Transcription of various genes is regulated by the cyclic AMP (cAMP) signal transduction pathway through a family of cAMP Responsive Element (CRE)-Binding transcription factors that include CREB, CREM (CRE Modulator), and ATF-1 (Activating Transcription Factor 1). The genes for these transcription factors encode multiple isoforms that are created by alternative splicing, alternative initiation codons, and alternative intronic promoters. Homo- and heterodimers of these members of the basic domain-and-leucine zipper superfamily of proteins bind the palindromic TGACGTCA sequence of CRE. CREB is expressed in all somatic cells, and many different stimuli activate CREB by phosphorylation of its serine 133 (S133). The transcriptional activity and specificity of CREB are regulated by the signaling pathways initiated by the various stimuli. Transcriptional regulation by CREB family members has been implicated in many physiological responses to extracellular and environmental stimuli, such as memory, tissue growth and development, and homeostasis.
The J151-21 monoclonal antibody recognizes the phosphorylated S133 of human CREB in addition to cross-reacting with S63 of human ATF-1.