Definition:

The TFIID basal transcription factor complex plays a major role in the initiation of RNA polymerase II (Pol II)-dependent transcription. TFIID recognizes and binds promoters with or without a TATA box via its subunit TBP, a TATA-box-binding protein, and promotes assembly of the pre-initiation complex (PIC). The TFIID complex consists of TBP and TBP-associated factors (TAFs), including TAF1, TAF2, TAF3, TAF4, TAF5, TAF6, TAF7, TAF8, TAF9, TAF10, TAF11, TAF12 and TAF13. The TFIID complex structure can be divided into 3 modules TFIID-A, TFIID-B, and TFIID-C. TAF6 homodimer connects TFIID modules, forming a rigid core.; [Isoform 4]: Transcriptional regulator which acts primarily as a positive regulator of transcription. Recruited to the promoters of a number of genes including GADD45A and CDKN1A/p21, leading to transcriptional up-regulation and subsequent induction of apoptosis. Also up-regulates expression of other genes including GCNA/ACRC, HES1 and IFFO1. In contrast, down-regulates transcription of MDM2. Acts as a transcriptional coactivator to enhance transcription of TP53/p53-responsive genes such as DUSP1. Can also activate transcription and apoptosis independently of TP53. Drives apoptosis via the intrinsic apoptotic pathway by up-regulating apoptosis effectors such as BCL2L11/BIM and PMAIP1/NOXA.