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 binds the cAMP response element, a DNA nucleotide sequence present in many viral and cellular promoters. The binding of CREB1 stimulates transcription. 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.