Oligodendrocyte transcription factor 2 (Olig2) is a basic-helix-loop-helix (bHLH) transcription factor that is involved in motoneuron and oligodendrocyte development []. Olig2 overexpression has been shown to enhance OPC (oligodendrocyte precursor cell) differentiation, maturation, and migration as well as remyelination following chemical demyelination. Therefore, OLIG2 overexpression in oligodendrocyte progenitor cells has been suggested to be a possible therapeutic mechanism for enhancing myelin repair []. Olig2 shares structure and protein sequence similarity with Olig1, 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 [].
