Schizosaccharomyces pombe atf1(+) encodes a transcription factor required for sexual development and entry into stationary phase
Schizosaccharomyces pombe atf1(+) encodes a transcription factor required for sexual development and entry into stationary phase
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DOI：
10.1002/j.1460-2075.1995.tb00310.x
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发表时间：
1995-12-15
期刊：
影响因子：
11.4
通讯作者：
Jones, N
中科院分区：
文献类型：
--
作者：
Takeda, T;Toda, T;Jones, N
我们描述了裂变酵母裂糖酵母（Schizosaccharomyces pombe）的atf1（+）基因编码的转录因子的鉴定和表征。因子Atf1在其c端含有一个bZIP结构域，与哺乳动物因子ATF/CREB家族成员具有很强的同源性，并且在体外特异性结合ATF/CRE识别位点。此外，在分裂酵母细胞提取物中检测到的ATF样结合活性在Atf1（+）基因缺失后完全丧失，当生长到饱和时，分裂酵母细胞退出有丝分裂周期，进入G(0)样固定期。atf1（-）细胞进入固定期受到限制，迅速丧失生存能力；除非cAMP水平升高，否则在最小培养基中不会发生这种情况，因此固定相进入似乎由cAMP负向调节，而由Atf1正向调节。atf1（-）细胞也是不育的，这种不育似乎是由于两个缺陷的结合：首先，在氮饥饿时，大多数atf1（-）细胞不能在细胞周期的G(1)期停止，其次，ste11（+）表达的诱导丧失，因此，ste11（+）的表达代表了cAMP途径负调控和atf1正调控事件的第二个例子。尽管它们密切相关，但这两种调节途径是独立运作的，并且Atf1的活性不受cAMP水平或改变cAMP信号通路组分活性的突变的直接调节，因此Atf1是一种转录因子，在细胞对不利环境条件的反应中起着重要作用，即退出有丝分裂细胞周期，进行性分化或进入静息状态。
We describe the identification and characterization of a transcription factor encoded by the atf1(+) gene of the fission yeast Schizosaccharomyces pombe. The factor Atf1, contains a bZIP domain at its C-terminus with strong homology to members of the ATF/CREB family of mammalian factors and in vitro binds specifically to ATF/CRE recognition sites, Furthermore the ATF-like binding activity detected in extracts from fission yeast cells is entirely lost upon deletion of the atf1(+) gene, Upon growth to saturation, fission yeast cells exit the mitotic cycle and enter a G(0)-like stationary phase, However, on rich medium, entry of atf1(-) cells into stationary phase is restricted and they rapidly lose viability; this does not occur on minimal medium unless cAMP levels are raised, Thus stationary phase entry appears to be regulated negatively by cAMP and positively by Atf1. atf1(-) cells are also sterile and this sterility appears to be due to a combination of two defects: first, upon nitrogen starvation the majority of atf1(-) cells fail to arrest in the G(1) phase of the cell cycle and second, the induction of ste11(+) expression is lost, Thus expression of ste11(+) represents a second example of an event that is negatively regulated by the cAMP pathway and positively regulated by Atf1. Despite their close association however, these two regulatory pathways function independently and Atf1 activity is not directly modulated by cAMP levels or mutations that alter the activity of components of the cAMP signalling pathway, Thus Atf1 is a transcription factor that plays an important role in the response of cells to adverse environmental conditions, which is to exit the mitotic cell cycle and either sexually differentiate or enter a resting state.