TGACGTCA

TGACGTCA is an eight-base pair DNA sequence that serves as the canonical cAMP response element (CRE), a cis-regulatory element involved in transcriptional responses to cyclic AMP signaling. The sequence is a perfect palindrome, enabling binding by CREB family transcription factors as dimers. CREs are commonly located in promoter and enhancer regions of genes responsive to cAMP and related signaling pathways.

Proteins that recognize CRE include CREB, CREM, and ATF family members. These factors bind the TGACGTCA motif and regulate transcription in response to cellular signals. CREB and partners can act as transcriptional activators or repressors depending on the cellular context and interacting coactivators.

The regulatory mechanism typically involves phosphorylation of CREB at Ser133 by protein kinases such as PKA, CaMKs, or MAPK-activated kinases. Phosphorylated CREB recruits the coactivator CBP/p300, which possesses histone acetyltransferase activity and facilitates chromatin remodeling, leading to transcriptional activation of CRE-containing genes.

Genomically, CRE elements are found in a wide range of vertebrate genes and contribute to the inducible expression patterns seen in response to hormonal signals, neuronal activity, and stress. They are frequently studied using CRE-luciferase reporter assays to quantify CRE-mediated transcription and are used to investigate signaling pathways that converge on CREB and related factors.

Historically, the CRE element was defined in the late 1980s as the DNA sequence recognized by CREB, establishing a central mechanism by which cAMP signaling controls gene expression. Related elements and variants broaden the regulatory landscape of CREB-family transcription factors.