SHARP1 encodes a transcription repressor factor that belongs to the Hairy/Enhancer of the Split subfamily of basic helix-loop-helix factors (bHLH). Sequence alignment shows that SHARP1 is only distantly related to these proteins with a 37-42% sequence identity within its bHLH domain. Unlike most other bHLH proteins, SHARP-1 is not expressed in neuronal progenitor cells or early differentiating neurons but is instead restricted to neuronal subset within the postnatal central nervous system (CNS).
