c-Jun and RACK1 homologues regulate a control point for sexual development in Aspergillus nidulans
c-Jun and RACK1 homologues regulate a control point for sexual development in Aspergillus nidulans
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DOI：
10.1046/j.1365-2958.2000.01954.x
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发表时间：
2000-07-01
影响因子：
3.6
通讯作者：
Braus, GH
中科院分区：
文献类型：
--
作者：
Hoffmann, B;Wanke, C;Braus, GH
氨基酸限制会导致丝状真菌（例如构巢曲霉）的有性子实体形成受损。饥饿信号被控制翻译前体生物合成的跨通路调节网络感知，并导致 c-Jun 同源物编码的转录激活因子的表达增加。在氨基酸存在的情况下，需要哺乳动物 RACK1 同源物 cpcB 的基因产物来抑制网络。在氨基酸饥饿条件下的生长允许真菌有性发育程序的启动，但在减数分裂完成之前阻止子实体形成。因此，在这个确定的控制点处的停滞会导致充满菌丝的微闭囊壳。添加氨基酸导致块的释放并完成发育成成熟子囊孢子。在氨基酸存在的情况下，构巢曲霉的 c-Jun 同源物的过表达或 RACK1 同源物 cpcB 的缺失会诱导相同的发育阻滞。因此，氨基酸饥饿信号通过网络调节性发育，该网络也控制氨基酸生物合成基因。 RACK1 基因的表达会抑制因 cpcB 缺失而导致的发育障碍。这些数据阐明了丝状真菌新陈代谢和性发育之间的联系。
Amino acid limitation results in impaired sexual fruit body formation in filamentous fungi such as Aspergillus nidulans. The starvation signal is perceived by the cross-pathway regulatory network controlling the biosynthesis of translational precursors and results in increased expression of a transcriptional activator encoded by a c-Jun homologue. In the presence of amino acids, the gene product of the mammalian RACK1 homologue cpcB is required to repress the network. Growth under amino acid starvation conditions permits the initiation of the sexual developmental programme of the fungus, but blocks fruit body formation before completion of meiosis. Accordingly, arrest at this defined control point results in microcleistothecia filled with hyphae. Addition of amino acids results in release of the block and completion of development to mature ascospores. The same developmental block is induced by either overexpression of c-Jun homologues or deletion of the RACK1 homologue cpcB of A. nidulans in the presence of amino acids. Therefore, the amino acid starvation signal regulates sexual development through the network that also controls the amino acid biosynthetic genes. Expression of the RACK1 gene suppresses the block in development caused by a deletion of cpcB. These data illuminate a connection between metabolism and sexual development in filamentous fungi.