Phosphoribosyl pyrophosphate synthetase, as a suppressor of the sepH mutation in Aspergillus nidulans, is required for the proper timing of septation
Phosphoribosyl pyrophosphate synthetase, as a suppressor of the sepH mutation in Aspergillus nidulans, is required for the proper timing of septation
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DOI：
10.1111/mmi.12026
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发表时间：
2012-11
影响因子：
3.6
通讯作者：
Guowei Zhong;Wenfan Wei;Q. Guan;Zhaofei Ma;Hua Wei;Xushi Xu;Shizhu Zhang;Ling Lu
中科院分区：
文献类型：
--
作者：
Guowei Zhong;Wenfan Wei;Q. Guan;Zhaofei Ma;Hua Wei;Xushi Xu;Shizhu Zhang;Ling Lu
适时的胞质分裂/分隔是构巢曲霉菌丝生长和分生孢子形成的必要条件。遗传分析表明，A. nidulans具有隔膜起始网络（SIN）途径的组分;其中之一SEPH是胞质分裂期间早期事件的关键参与者。然而，很少有人知道如何SEPH激酶级联是由其他组件的调节。在这里，我们证明了磷酸核糖焦磷酸合成酶家族对SIN具有拮抗作用，因此AnPRS家族的下调可以绕过SIN对隔膜形成和分生孢子的要求。Anprs基因家族的转录缺陷伴随Anprs活性的降低，导致过度分隔的形成以及在缺乏SEPH的情况下分隔和分生孢子的恢复。显然，分隔的时间和位置与AnPRS活性有关。此外，通过广泛的酵母双杂交分析和拯救组合实验，证明AnPRS成员能够形成功能相互作用实体的异源二聚体，但它们的贡献似乎不相等，Anprs 1突变体显示相对正常的分隔，但Anprs 2缺失是致命的。因此，与酵母相比，AnPRS家族在丝状真菌的分离过程中可能具有独特的调节机制。
Timely cytokinesis/septation is essential for hyphal growth and conidiation in Aspergillus nidulans. Genetic analyses have identified that A. nidulans has components of the septum initiation network (SIN) pathway; one of these, SEPH, is a key player for early events during cytokinesis. However, little is known about how the SEPH kinase cascade is regulated by other components. Here, we demonstrate that the phosphoribosyl pyrophosphate synthetase family acts antagonistically against the SIN so that the downregulation of AnPRS family can bypass the requirements of the SIN for septum formation and conidiation. The transcription defect of the Anprs gene family accompanied with the reduction of AnPRS activity causes the formation of hyper‐septation as well as the restoration of septation and conidiation in the absence of SEPH. Clearly, the timing and positioning of septation is related to AnPRS activity. Moreover, with the extensive yeast two‐hybrid analysis and rescue combination experiments, it demonstrated that AnPRS members are able to form the heterodimers for functional interacting entities but they appear to contribute so unequally that Anprs1 mutant display relatively normal septation, but Anprs2 deletion is lethal. Thus, compared to in yeast, the AnPRS family may have a unique regulation mechanism during septation in filamentous fungi.