Oligodendrocyte transcription factor 1 (Olig1) is a basic-helix-loop-helix (bHLH) transcription factor that promotes oligodendrocyte progenitor cell commitment, differentiation, and subsequent myelination primarily in brain, but not spinal cord [, ]. Olig1 shares structure and protein sequence similarity with Olig2, however, they have non-overlapping developmental functions in patterning, neuron subtype specification and the formation of oligodendrocytes [].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 [].
