"Basic helix-loop-helix family, member e41", or BHLHE41, is a gene that encodes, as the name implies, a basic helix-loop-helix protein in various tissues of both humans and mice. It also known as DEC2, hDEC2, and SHARP1, and was previously known as "basic helix-loop-helix domain containing, class B, 3", or BHLHB3.
This gene encodes a transcription factor that belongs to the Hairy/Enhancer of Split subfamily of basic helix-loop-helix factors. The encoded protein functions as a transcriptional repressor and as a regulator of molecular clock.
In mice lacking SHARP1 and SHARP2, IGF-2 is elevated and so memory consolidation is enhanced.
Defects in this gene are associated with the short sleep phenotype . A particular genetic variation in the gene affects sleep duration in humans, and introduction of the human gene into mice also reduces their sleep requirements. This genetic variation was discovered by Ying-Hui Fu's lab.