Role of multifunctional autonomously replicating sequence binding factor 1 in the initiation of DNA replication and transcriptional control in Saccharomyces cerevisiae.
Role of multifunctional autonomously replicating sequence binding factor 1 in the initiation of DNA replication and transcriptional control in Saccharomyces cerevisiae.
复制标题
多功能自主复制序列结合因子 1 在酿酒酵母 DNA 复制启动和转录控制中的作用。
DOI：
10.1128/mcb.12.3.1064-1077.1992
复制
发表时间：
1992
影响因子：
5.3
通讯作者：
Campbell,JL
中科院分区：
文献类型：
--
作者：
Rhode,PR;Elsasser,S;Campbell,JL
自主复制序列(ARS)结合因子1(ABF1)是一种丰富的DNA结合蛋白，在酵母基因组中的许多位置特异性识别RTCRYN5ACG基序，包括启动子元件、交配型沉默因子和ARSS。对这些位点的突变分析表明，ABF1参与了结构性和碳源调节的转录激活、转录沉默和ARS活性。为了更好地评估ABF1在DNA复制和转录控制中的作用，我们分离了ABF1基因中对温度敏感的致命突变。几株abf1(Ts)菌株在不允许的温度下表现出快速生长停滞。在半允许温度下，这些菌株在ARS-CEN质粒的有丝分裂稳定性方面显示出ARS特有的缺陷，以至于abf1突变株在ARS功能上表现出与许多研究者先前分析的携带AS作用ABF1结合位点突变的突变株相同的缺陷。对α因子同步化的ABF1(Ts)株进行的流式细胞仪分析和体内标记实验表明，在不允许的温度下，这些细胞不能有效地从G1期进入S期，合成的DNA水平是同基因ABF1株的25%。在abf1(Ts)菌株中，RNA合成也减少。此外，在半允许温度下，由ABF1结合位点上游激活序列激活的转录在anabf1(Ts)株中是完全缺陷的。这些表型提供了相同的蛋白质ABF1在启动DNA复制和转录激活中发挥作用的证据。
Autonomously replicating sequence (ARS) binding factor 1 (ABF1) is an abundant DNA-binding protein that specifically recognizes the motif RTCRYN5ACG at many sites in the yeast genome, including promoter elements, mating-type silencers, and ARSs. Mutational analysis of these sites suggests that ABF1 is involved in constitutive and carbon source-regulated transcriptional activation, transcriptional silencing, and ARS activity. To better assess the role of ABF1 in DNA replication and transcriptional control, temperature-sensitive lethal mutations in theABF1gene were isolated. Several of theabf1(Ts) strains show rapid growth arrest at the nonpermissive temperature. At the semipermissive temperature, these strains show an ARS-specific defect in the mitotic stability ofARS-CENplasmids, such that theabf1mutants show defects in ARS function identical to those of mutants bearing the mutations in the as-acting ABF1 binding sites analyzed previously by numerous investigators. Flow cytometric analysis and in vivo DNA labeling experiments on an α-factor synchronizedabf1(Ts) strain showed that at the nonpermissive temperature, these cells fail to progress efficiently from G1through S phase and synthesize DNA at 25% of the level seen in the isogenicABF1strain. RNA synthesis is also reduced in theabf1(Ts) strains. In addition, transcriptional activation by an ABF1 binding site upstream activation sequence is completely defective in anabf1(Ts) strain at the semipermissive temperature. These phenotypes provide evidence that the same protein, ABF1, functions in the initiation of DNA replication and transcriptional activation.