Wang Hongchen, Chen Qiuyi, Zhang Shizhu, Lu Ling
Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Microbiology, College of Life Sciences, Nanjing Normal University, Nanjing 210023, China.
J Fungi (Basel). 2021 Oct 28;7(11):920. doi: 10.3390/jof7110920.
Transient Receptor Potential (TRP) proteins constitute a superfamily that encodes transmembrane ion channels with highly diverse permeation and gating properties. Filamentous fungi possess putative TRP channel-encoded genes, but their functions remain elusive. Here, we report that a putative TRP-like calcium channel, in the filamentous fungus , performs important roles in conidiation and in adapting to cell wall disruption reagents in a high temperature-induced defect-dependent manner, especially under a calcium-limited culture condition. The genetic and functional relationship between TrpR and the previously identified high-affinity calcium channels CchA/MidA indicates that TrpR has an opposite response to CchA/MidA when reacting to cell wall disruption reagents and in regulating calcium transients. However, a considerable addition of calcium can rescue all the defects that occur in TrpR and CchA/MidA, meaning that calcium is able to bypass the necessary requirement. Nevertheless, the colocalization at the membrane of the Golgi for TrpR and the P-type Golgi Ca ATPase PmrA suggests two channels that may work as ion transporters, transferring Ca from the cytosol into the Golgi apparatus and maintaining cellular calcium homeostasis. Therefore, combined with data for the deletion mutant revealing abnormal cell wall structures, TrpR works as a Golgi membrane calcium ion channel that involves cell wall integration.
瞬时受体电位（TRP）蛋白构成一个超家族，该超家族编码具有高度多样的通透和门控特性的跨膜离子通道。丝状真菌拥有推测的TRP通道编码基因，但其功能仍然未知。在此，我们报道在丝状真菌中一个推测的类TRP钙通道在分生孢子形成以及以高温诱导缺陷依赖的方式适应细胞壁破坏试剂方面发挥重要作用，尤其是在钙限制培养条件下。TrpR与先前鉴定的高亲和力钙通道CchA/MidA之间的遗传和功能关系表明，在对细胞壁破坏试剂作出反应以及调节钙瞬变时，TrpR与CchA/MidA具有相反的反应。然而，大量添加钙可以挽救在TrpR和CchA/MidA中出现的所有缺陷，这意味着钙能够绕过必要的需求。尽管如此，TrpR与P型高尔基体钙ATP酶PmrA在高尔基体膜上的共定位表明这两个通道可能作为离子转运体发挥作用，将Ca从细胞质转运到高尔基体中并维持细胞钙稳态。因此，结合缺失突变体显示异常细胞壁结构的数据，TrpR作为一个涉及细胞壁整合的高尔基体膜钙离子通道发挥作用。
