A wealth of data is accumulating on the physiological functions of human Rac1, a member of the Rho GTPase family of molecular switches and substrate of botulinum toxin, which was first identified as a regulator of cell motility through its effect on the actin cytoskeleton. Later on, it was found to be involved in different diseases like cancers, cardiac function, neuronal disorders, and apoptotic cell death. Despite the presence of Rac1 homologues in most fungi investigated so far, including Rho5 in the genetically tractable model yeast Saccharomyces cerevisiae, knowledge on their physiological functions is still scarce, let alone the details of the molecular mechanisms of their actions and interactions. Nevertheless, all functions proposed for human Rac1 seem to be conserved in one or the other fungus. This includes the regulation of MAPK cascades, polarized growth, and actin dynamics. Moreover, both the production and response to reactive oxygen species, as well as the reaction to nutrient availability, can be affected. We here summarize the studies performed on fungal Rac1 homologues, with a special focus on S. cerevisiae Rho5, which may be of use in drug development in medicine and agriculture.

中文翻译：

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人Rac1的真菌同源物在信号转导和形态发生中起新兴作用。

关于人类Rac1（Rho GTPase分子开关的成员和肉毒杆菌毒素底物）的生理功能的大量数据正在积累，该蛋白首先通过对肌动蛋白细胞骨架的作用而被确定为细胞运动的调节剂。后来发现它与癌症，心脏功能，神经元疾病和凋亡性细胞死亡等各种疾病有关。尽管迄今为止研究的大多数真菌中都存在Rac1同源物，包括遗传上易处理的模型酵母酿酒酵母中的Rho5，关于它们的生理功能的知识仍然很匮乏，更不用说它们作用和相互作用的分子机制的细节了。尽管如此，为人类Rac1提议的所有功能似乎都在一种或另一种真菌中得以保留。这包括MAPK级联，极化增长和肌动蛋白动力学的调节。此外，对活性氧的产生和反应以及对养分利用率的反应都可能受到影响。我们在这里总结了对真菌Rac1同源物进行的研究，特别关注酿酒酵母Rho5，它可能在医学和农业领域的药物开发中使用。