TAF1（TATA-box binding protein associated factor 1）是转录起始因子TFIID的核心组成部分，属于TAF基因家族（TBP-associated factors）。该家族成员均与TATA结合蛋白（TBP）形成复合物，共同参与RNA聚合酶II介导的基因转录起始。TAF1具有多重功能域，包括组蛋白乙酰转移酶（HAT）活性和泛素连接酶活性，能通过乙酰化组蛋白打开染色质结构促进转录，同时参与细胞周期调控和DNA损伤修复。其主要作用位点为基因启动子区域，通过与TBP及其他TAF蛋白协同识别核心启动子元件（如TATA框或起始子Inr）。TAF1突变可导致其与DNA结合能力下降或TFIID复合体组装异常，引发转录失调。已发现TAF1突变与X连锁智力障碍综合征（如MRX33型）和某些癌症（如结直肠癌）相关，其异常表达会破坏细胞增殖与分化平衡。当TAF1过表达时，可能过度激活原癌基因转录，促进肿瘤发生；而低表达则导致管家基因（housekeeping genes）转录不足，影响基础细胞功能。TAF家族共性在于均含有保守的TAF结构域，能够介导蛋白互作并稳定转录前起始复合物（PIC），部分成员还具有组织特异性表达模式。例如TAF1在神经元中高表达，其功能缺陷会直接影响神经发育相关基因的转录水平。

由RNA聚合酶II转录起始需要70多个多肽的活动。它协调这些活动的蛋白质是基础转录因子TFIID，其结合的核心启动子正确定位聚合酶，作为支架的转录复合物的其余部分的组件，并作为调节信号的信道。 TFIID是由TATA结合蛋白（TBP）和一组被称为TBP相关因子或TAFS进化保守的蛋白质的。 TAFS可能参与基础转录，作为共激活因子，功能的启动子识别或修改一般转录因子（基转移酶），以方便复杂的组装和转录起始。该基因编码TFIID的最大亚基。此亚基结合于包含转录起始位点的核心启动子序列。它还结合到活化剂和其它转录调节，并且这些相互作??用影响转录起始的速率。这种亚单位含有在N-和C-末端的两个独立的蛋白激酶结构域，但也具有乙酰转移酶活性，并且可以作为泛素活化/偶联酶。在该基因导致肌张力障碍3，扭转突变，X连锁，一个张力障碍 - 帕金森症。这个基因的选择性剪接的结果在多个转录变体。该基因是一个复杂的转录单位（TAF1 / DYT3），其中，一些转录物变体与TAF1共享的外显子以及其他下游DYT3外显子的一部分。 [由RefSeq的，2013年10月提供]

TATA-box binding protein associated factor 1 (TAF1) is a critical core subunit of the general transcription factor TFIID, belonging to the TBP-associated factor (TAF) family that collectively facilitates RNA polymerase II-mediated transcription initiation. As a multi-domain protein, TAF1 integrates several distinct functional activities, including histone acetyltransferase (HAT) and ubiquitin ligase capabilities, which allow it to remodel chromatin structure by acetylating histones to promote an open, transcriptionally accessible state, while also contributing to cell cycle regulation and DNA damage repair. Operating primarily at gene promoter regions, TAF1 synergizes with TATA-binding protein (TBP) and other TAF subunits to recognize core promoter elements such as the TATA box or Initiator (Inr), thereby stabilizing the pre-initiation complex (PIC) through conserved TAF domains that mediate essential protein-protein interactions. Disruptions in TAF1 function, whether through mutations that impair DNA binding or TFIID assembly, or through dysregulated expression levels, can lead to significant transcriptional dysregulation; for instance, overexpression may aberrantly activate oncogene transcription and drive tumorigenesis, particularly in contexts such as colorectal cancer, whereas underexpression compromises the transcription of essential housekeeping genes, disrupting basic cellular maintenance. Clinically, TAF1 mutations have been linked to X-linked intellectual disability syndromes, such as MRX33, and various malignancies, reflecting its role in maintaining the balance between cellular proliferation and differentiation. Given its high expression in neurons, TAF1 is particularly vital for neurodevelopment, where its functional integrity directly influences the transcriptional landscape of neural-specific genes, underscoring its broader importance in both developmental biology and disease pathogenesis.

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