Cyclic AMP-responsive element-binding protein 3-like protein 1 is a protein in humans that is encoded by CREB3L1 gene. Cyclic AMP-responsive element-binding protein 3-like protein 1 is a protein that in humans is encoded by the CREB3L1 gene. The protein encoded by this gene is normally found in the membrane of the endoplasmic reticulum (ER). However, upon stress to the ER, the encoded protein is cleaved and the released cytoplasmic transcription factor domain translocates to the nucleus. There it activates the transcription of target genes by binding to box-B elements.