PROTEIN-KINASE-A MEDIATES GROWTH-REGULATED EXPRESSION OF YEAST RIBOSOMAL-PROTEIN GENES BY MODULATING RAP1 TRANSCRIPTIONAL ACTIVITY
PROTEIN-KINASE-A MEDIATES GROWTH-REGULATED EXPRESSION OF YEAST RIBOSOMAL-PROTEIN GENES BY MODULATING RAP1 TRANSCRIPTIONAL ACTIVITY
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DOI：
10.1128/mcb.14.3.1920
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发表时间：
1994-03-01
影响因子：
5.3
通讯作者：
STRUHL, K
中科院分区：
文献类型：
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作者：
KLEIN, C;STRUHL, K
酵母核糖体蛋白基因作为细胞生长的函数被协调调节; RNA水平在氨基酸饥饿期间降低，但在碳源上调之后增加。RAP 1是一种多功能转录因子，其结合位点存在于几乎所有的核糖体蛋白基因中，并与生长速率调节相关。我们发现，核糖体蛋白的mRNA水平增加两倍的菌株，具有组成性高水平的环AMP依赖性蛋白激酶（蛋白激酶A [PKA]）的活性。PKA依赖性诱导需要RAP 1结合位点，它反映了RAP 1增加的转录激活。核糖体蛋白基因的生长调节转录强烈依赖于PKA活性的调节能力。具有组成性高PKA水平的细胞不显示响应于氨基酸饥饿的转录降低。相反，在具有组成性低PKA活性的细胞中，核糖体蛋白mRNA水平较低，并且在碳源上移时基本上不可诱导。我们认为PKA对RAP 1转录活性的调节是核糖体蛋白基因生长调节表达的原因。
Yeast ribosomal protein genes are coordinately regulated as a function of cell growth; RNA levels decrease during amino acid starvation but increase following a carbon source upshift. Binding sites for RAP1, a multifunctional transcription factor, are present in nearly all ribosomal protein genes and are associated with growth rate regulation. We show that ribosomal protein mRNA levels are increased twofold in strains that have constitutively high levels of cyclic AmP-dependent protein kinase (protein kinase A [PKA]) activity. The PKA-dependent induction requires RAP1 binding sites, and it reflects increased transcriptional activation by RAP1. Growth-regulated transcription of ribosomal protein genes strongly depends on the ability to regulate PKA activity. Cells with constitutively high PKA levels do not show the transcriptional decrease in response to amino acid starvation. Conversely, in cells with constitutively low PKA activity, ribosomal protein mRNAs levels are lower and largely uninducible upon carbon source upshift. We suggest that modulation of RAP1 transcriptional activity by PKA accounts for growth-regulated expression of ribosomal protein genes.