BHLHE40
Description
The BHLHE40 (basic helix-loop-helix family member e40) is a protein-coding gene located on chromosome 3.
BHLHE40, also known as DEC1, is a transcriptional repressor involved in the regulation of the circadian rhythm. It acts as the negative limb of a novel autoregulatory feedback loop (DEC loop) distinct from the PER/CRY loop. Both loops are interlocked: BHLHE40 represses the expression of PER1/2, while being repressed by PER1/2 and CRY1/2. BHLHE40 represses the activity of the circadian transcriptional activator CLOCK-BMAL1/BMAL2 heterodimer by competing for binding to E-box elements. It negatively regulates its own expression and the expression of DBP and BHLHE41/DEC2. BHLHE40 acts as a corepressor of RXR and RXR-LXR heterodimers, repressing the ligand-induced RXRA and NR1H3/LXRA transactivation activity. It may regulate chondrocyte differentiation via the cAMP pathway. BHLHE40 represses the transcription of NR0B2 and attenuates its transactivation by the CLOCK-BMAL1 complex. It drives the circadian rhythm of blood pressure through transcriptional repression of ATP1B1 in the cardiovascular system. {ECO:0000269|PubMed:12397359, ECO:0000269|PubMed:14672706, ECO:0000269|PubMed:15193144, ECO:0000269|PubMed:15560782, ECO:0000269|PubMed:18411297, ECO:0000269|PubMed:19786558, ECO:0000269|PubMed:28797635, ECO:0000269|PubMed:30012868}
BHLHE40 is also known as BHLHB2, Clast5, DEC1, HLHB2, SHARP-2, SHARP2, STRA13, Stra14.
