Altmann H, Wendler W, Winnacker E L
Institut für Biochemie der Ludwig-Maximilians-Universität, Martinsried, Germany.
Proc Natl Acad Sci U S A. 1994 Apr 26;91(9):3901-5. doi: 10.1073/pnas.91.9.3901.
Members of the CCAAT-binding transcription factor (CTF) family of proteins stimulate the initiation of adenovirus DNA replication and act as transcriptional activators. To investigate the mechanisms underlying CTF-mediated transactivation patterns, we expressed several natural CTF variants in Saccharomyces cerevisiae and determined their transactivating activities in enzymatic assays. CTF7, which lacks the entire proline-rich region previously thought to mediate transcriptional activation by CTF proteins, enhances transcription to a greater degree than full-length CTF1, which contains the putative activation domain. CTF2, which contains a partially deleted proline-rich activation region, does not stimulate transcription at all. These findings indicate that the proline-rich region of CTF proteins is not essential for transcriptional activation in yeast. Our studies also suggest a bipartite two-domain structure of CTF-type transcriptional activation domains.
CCAAT结合转录因子（CTF）家族的蛋白质成员可刺激腺病毒DNA复制的起始，并作为转录激活因子发挥作用。为了研究CTF介导的反式激活模式背后的机制，我们在酿酒酵母中表达了几种天然CTF变体，并在酶促试验中测定了它们的反式激活活性。CTF7缺乏先前认为介导CTF蛋白转录激活的整个富含脯氨酸区域，其增强转录的程度比包含推定激活域的全长CTF1更大。CTF2包含部分缺失的富含脯氨酸的激活区域，根本不刺激转录。这些发现表明，CTF蛋白的富含脯氨酸区域对于酵母中的转录激活并非必不可少。我们的研究还提出了CTF型转录激活域的二分双结构域结构。
