Abstract Carbamoyl phosphate synthetase is involved in arginine biosynthesis in many organisms. In this study, we investigate the biological function of Cpa1, a small subunit of carbamoyl phosphate synthetase of Colletotrichum gloeosporioides. The deletion of the CPA1 gene affected vegetative growth, arginine biosynthesis, and fungal pathogenicity. Genetic complementation with native CPA1 fully recovered all these defective phenotypes. We observed that Cpa1-RFP fusion protein is localized at the mitochondria, which is consistent with Cpa2, a large subunit of carbamoyl phosphate synthetase. We identified the proteins that interact with Cpa1 by using the two-hybrid screen approach, and we showed that Dut1 interacts with Cpa1 but without Cpa2 in vivo. Dut1 is dispensable for hyphal growth, appressorial formation, and fungal pathogenicity. Interestingly, the Dut1-Cpa1 complex is localized at the mitochondria. Further studies showed that Dut1 regulates Cpa1-Cpa2 interaction in response to arginine. In summary, our studies provide new insights into how Cpa1 interacts with its partner proteins to mediate arginine synthesis.

中文翻译：

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氨基甲酰磷酸合成酶亚基 Cpa1 与 Dut1 相互作用，控制胶孢炭疽菌的发育、精氨酸生物合成和致病性

摘要 氨基甲酰磷酸合成酶参与许多生物体的精氨酸生物合成。在这项研究中，我们调查了 Cpa1 的生物学功能，Cpa1 是胶孢炭疽菌的氨基甲酰磷酸合成酶的一个小亚基。CPA1 基因的缺失影响营养生长、精氨酸生物合成和真菌致病性。与天然 CPA1 的遗传互补完全恢复了所有这些有缺陷的表型。我们观察到 Cpa1-RFP 融合蛋白定位于线粒体，这与 Cpa2（氨基甲酰磷酸合成酶的一个大亚基）一致。我们通过使用双杂交筛选方法鉴定了与 Cpa1 相互作用的蛋白质，并且我们表明 Dut1 在体内与 Cpa1 相互作用但没有 Cpa2。Dut1 对于菌丝生长、附着物形成和真菌致病性是可有可无的。有趣的是，Dut1-Cpa1 复合物位于线粒体。进一步的研究表明，Dut1 调节 Cpa1-Cpa2 相互作用以响应精氨酸。总之，我们的研究为 Cpa1 如何与其伙伴蛋白相互作用以介导精氨酸合成提供了新的见解。