Synonyms:BHLHE34, TCFEC, TFECL Background:Transcriptional regulator that acts as a repressor or an activator. Acts as a transcriptional repressor on minimal promoter containing element F(that includes an E-box sequence). Binds to element F in an E-box sequence-specific manner. Acts as a transcriptional transactivator on the proximal promoter region of the tartrate-resistant acid phosphatase(TRAP) E-box containing promoter(By similarity). Collaborates with MITF in target gene activation(By similarity). Acts as a transcriptional repressor on minimal promoter containing mu E3 enhancer sequence(By similarity). Binds to mu E3 DNA sequence of the immunoglobulin heavy-chain gene enhancer(By similarity). Binds DNA in a homo-or heterodimeric form.