Glucose sensing via the protein kinase A pathway in Schizosaccharomyces pombe
Glucose sensing via the protein kinase A pathway in Schizosaccharomyces pombe
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DOI：
10.1042/bst0330257
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发表时间：
2005-02-01
影响因子：
3.9
通讯作者：
Hoffman, CS
中科院分区：
文献类型：
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作者：
Hoffman, CS
裂殖酵母裂殖酵母主要通过cAMP信号通路检测葡萄糖。该途径的组成部分包括Git 3 G蛋白偶联受体和异源三聚体G蛋白，Gpa 2 G α亚基从该异源三聚体G蛋白激活腺苷酸环化酶（Git 2/Cyr 1）。甚至在表达活化形式的Gpa 2的菌株中也需要三种额外的蛋白质Git 1、Git 7和Git 10来产生cAMP应答，所述活化形式的Gpa 2能够绕过GPCR和G β-γ二聚体的损失。因此，Git 1、Git 7和Git 10要么以不依赖于G蛋白的方式起作用，要么是稳定或组装功能性信号复合物所必需的。虽然先前的数据表明，Cgs 2 cAMP磷酸二酯酶（PDE）不调节cAMP的反应，我们现在有证据表明，沿着腺苷酸环化酶的调节，PDE激活是重要的限制对葡萄糖的反应。最后，蛋白激酶A激活的调节似乎涉及cAMP途径组分的功能的传统翻译后调节和这些cAMP途径基因中的一些的葡萄糖依赖性转录调节。
The fission yeast Schizosaccharomyces pombe primarily detects glucose via a cAMP-signalling pathway. Components of this pathway include the Git3 G-protein-coupled receptor and a heterotrimeric G-protein, from which the Gpa2 Galpha subunit activates adenylate cyclase (Git2/Cyr1). Three additional proteins, Git1, Git7 and Git10 are required to generate a cAMP response even in a strain expressing an activated form of Gpa2, which is capable of bypassing the loss of the GPCR and Gbetagamma dimer. Therefore, Git1, Git7 and Git10 either act in a G-protein-independent manner or are required to stabilize or assemble a functional signalling complex. Although prior data suggested that the Cgs2 cAMP phosphodiesterase (PDE) does not regulate the cAMP response, we now have evidence that along with adenylate cyclase regulation, PDE activation is important for limiting the response to glucose. Finally, regulation of protein kinase A activation appears to involve both traditional post-translational regulation of the function of the components of the cAMP pathway and glucose-dependent transcriptional regulation of some of these cAMP pathway genes.