Transcription factor ATOH1, previously known as Protein atonal homologue 1 (ATOH1/Math1), is a basic helix-loop-helix (bHLH) transcription factor that is essential for the differentiation of hair cells (HCs), mechanotransducers that convert sound into auditory signals in the mammalian organ of Corti (OC) []. It also controls cerebellar granule cells - the most abundant neurons in the mammalian brain - differentiation []. ATOH1 has been found to affect the differentiation of cancer cells [, ].The bHLH (basic Helix-Loop-Helix) proteins contain the bHLH domain that is approximately 60 amino acids long and consists of a DNA-binding basic region followed by two a-helices separated by a variable loop region (HLH). The HLH domain promotes dimerisation, allowing the formation of homo- or heterodimeric complexes between different family members. Many bHLH proteins have been shown to act as transcriptional regulators [].
