CAMP responsive element binding protein 1, also known as CREB-1, is a protein that in humans is encoded by the CREB1 gene. This protein is a CREB transcription factor that is a member of the leucine zipper family of DNA-binding proteins. This protein binds as a homodimer to the cAMP-responsive element, an octameric palindrome. The protein is phosphorylated by several protein kinases, and induces transcription of genes in response to hormonal stimulation of the cAMP pathway.