Genetic evidence for transcriptional activation by the yeast IME1 gene product.
Genetic evidence for transcriptional activation by the yeast IME1 gene product.
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酵母 IME1 基因产物转录激活的遗传证据。
DOI：
10.1093/genetics/133.4.775
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发表时间：
1993
期刊：
影响因子：
3.3
通讯作者：
Mitchell,AP
中科院分区：
文献类型：
--
作者：
Smith,HE;Driscoll,SE;Sia,RA;Yuan,HE;Mitchell,AP
IME 1是酵母减数分裂和IME 2及其他早期减数分裂基因表达所必需的。IME 1是一种由360个氨基酸组成的多肽，具有中央和C-末端富含酪氨酸的区域。我们在这里报告的融合蛋白组成的莱克萨DNA结合结构域和IME 1激活体内的报告基因含有上游莱克萨结合位点的转录。融合蛋白的激活与天然IME 1活性具有几个特征：两者都依赖于RIM 11基因产物;两者都受到相同的IME 1错义突变的损害;两者都通过基因内抑制因子恢复。当与莱克萨融合时，中心富含酪氨酸的区域足以激活转录。该推定的激活结构域的缺失导致缺陷的IME 1衍生物。缺失衍生物的功能通过与酸性疱疹病毒VP 16活化结构域融合而恢复。C-末端富含酪氨酸的区域是转录激活的关键;相反，它使激活依赖于饥饿和RIM 11。免疫荧光研究表明，IME 1-lacZ融合蛋白集中在细胞核中。这些观察结果与其中IME 1通过在IME 2 5'调控区提供转录激活结构域而正常刺激IME 2表达的模型一致。
IME1 is required in yeast for meiosis and for expression of IME2 and other early meiotic genes. IME1 is a 360-amino acid polypeptide with central and C-terminal tyrosine-rich regions. We report here that a fusion protein composed of the lexA DNA-binding domain and IME1 activates transcription in vivo of a reporter gene containing upstream lexA binding sites. Activation by the fusion protein shares several features with natural IME1 activity: both are dependent on the RIM11 gene product; both are impaired by the same ime1 missense mutations; both are restored by intragenic suppressors. The central tyrosine-rich region is sufficient to activate transcription when fused to lexA. Deletion of this putative activation domain results in a defective IME1 derivative. Function of the deletion derivative is restored by fusion to the acidic Herpesvirus VP16 activation domain. The C-terminal tyrosine-rich region is dispensable for transcriptional activation; rather it renders activation dependent upon starvation and RIM11. Immunofluorescence studies indicate that an IME1-lacZ fusion protein is concentrated in the nucleus. These observations are consistent with a model in which IME1 normally stimulates IME2 expression by providing a transcriptional activation domain at the IME2 5' regulatory region.