GLUCOSE REPRESSION OF TRANSCRIPTION OF THE SCHIZOSACCHAROMYCES POMBE FBP1 GENE OCCURS BY A CAMP SIGNALING PATHWAY
GLUCOSE REPRESSION OF TRANSCRIPTION OF THE SCHIZOSACCHAROMYCES POMBE FBP1 GENE OCCURS BY A CAMP SIGNALING PATHWAY
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DOI：
10.1101/gad.5.4.561
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发表时间：
1991-04-01
影响因子：
10.5
通讯作者：
WINSTON, F
中科院分区：
文献类型：
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作者：
HOFFMAN, CS;WINSTON, F
粟酒裂殖酵母fbp 1基因编码果糖-1，6-二磷酸酶，其转录受葡萄糖抑制. 先前的工作已经证明，这种抑制需要几个基因（git基因）。 在这份报告中，我们证明，这些基因之一，git 2，是相同的，作为git 1基因，它编码腺苷酸环化酶，和git 2的功能丧失突变导致组成型fbp 1转录。 向生长培养基中添加cAMP抑制了git 2突变体以及携带6个额外git基因中任一个突变的菌株中的转录缺陷。 同样，外源性cAMP抑制fbp 1转录在野生型细胞上生长的一个令人沮丧的碳源。 在不同的git 2突变体中腺苷酸环化酶活性的不同水平，加上一些git 2突变体显示基因内互补的结果，强烈表明腺苷酸环化酶作为一个多聚体，不同的git 2突变改变不同的腺苷酸环化酶活性，包括催化活性和对葡萄糖的反应。 进一步的实验表明，这种cAMP信号通路不依赖于S。pombe ras 1基因，通过激活cAMP依赖性蛋白激酶发挥作用。
Transcription of the fbp 1 gene, encoding fructose-1,6-bisphosphatase, of Schizosaccharomyces pombe is subject to glucose repression. Previous work has demonstrated that several genes (git genes) are required for this repression. In this report we demonstrate that one of these genes, git2, is the same as the cyr1 gene, which encodes adenylate cyclase, and that loss-of-function mutations in git2 cause constitutive fbp1 transcription. Addition of cAMP to the growth medium suppresses the transcriptional defect in git2 mutants as well as in strains that carry mutations in any of six additional git genes. Similarly, exogenous cAMP represses fbp1 transcription in wild-type cells grown on a depressing carbon source. Different levels of adenylate cyclase activity in different git2 mutants, coupled with the result that some git2 mutants display intragenic complementation, strongly suggest that adenylate cyclase acts as a multimer and that different git2 mutations alter distinct activities of adenylate cyclase, including catalytic activity and response to glucose. Additional experiments demonstrate that this cAMP signaling pathway is independent of the S. pombe ras1 gene and works by activation of cAMP-dependent protein kinase.