DNA-binding domain of T-box transcription factor 21 and related T-box proteins
TBX21 (also known as T-cell-specific T-box transcription factor T-bet or transcription factor TBLYM) is a lineage-defining transcription factor which directs T helper type 1 (Th1) cell differentiation. It initiates Th1 lineage development from naive T helper precursor cells both by initiating the Th1 genetic programs and by inhibiting the opposing Th2 and Th17 lineage-commitment programs. This subfamily belongs to the T-box family of transcription factors which play a multitude of diverse functions throughout development. The founding member of the T-box family is Brachyury (also known as TBXT, or T). T-box family members share a conserved DNA-binding domain (T-box) which binds DNA in a sequence-specific manner. Common features shared by T-box family members are DNA-binding and transcriptional regulatory activity, a role in development, and conserved expression patterns.