State Key Laboratory of Agrobiotechnology, Beijing 100193, China.
MOA Key Lab of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing 100193, China.
Int J Mol Sci. 2022 May 22;23(10):5819. doi: 10.3390/ijms23105819.
In animals, malectin is well known to play an essential role in endoplasmic reticulum quality control (ERQC) by interacting with ribophorin I, one unit of the oligosaccharyltransferase (OST) complex. However, the functions of malectin in plants remain largely unknown. Here, we demonstrate the rice is an ER- and Golgi-associated malectin protein and physically interacts with rice homolog of ribophorin I (OsRpn1), and its disruption leads to spontaneous lesion mimic lesions, enhanced disease resistance, and prolonged ER stress. In addition, there are many more -glycosites and -glycoproteins identified from the mutant than wildtype. Furthermore, OsSERK1 and OsSERK2, which have more -glycosites in , were demonstrated to interact with OsMLD1. can suppress OsSERK1- or OsSERK2-induced cell death. Thus, may play a similar role to its mammalian homologs in glycoprotein quality control, thereby regulating cell death and immunity of rice, which uncovers the function of malectin in plants.
在动物中，甘露糖结合凝集素（malectin）通过与寡糖转移酶（OST）复合物的一个单元核糖体蛋白 I（ribophorin I）相互作用，在内质网质量控制（ERQC）中发挥着重要作用。然而，甘露糖结合凝集素在植物中的功能在很大程度上仍然未知。在这里，我们证明水稻 MLN51 是一种内质网和高尔基体相关的甘露糖结合凝集素蛋白，与水稻核糖体蛋白 I（OsRpn1）的同源物相互作用，其缺失会导致自发性病变模拟病变、增强抗病性和延长内质网应激。此外，从 突变体中鉴定出的 N-糖基化位点和 N-糖蛋白比野生型多。此外，具有更多 N-糖基化位点的 OsSERK1 和 OsSERK2 被证明与 OsMLD1 相互作用。MLN51 可以抑制 OsSERK1 或 OsSERK2 诱导的细胞死亡。因此，MLN51 可能在糖蛋白质量控制中发挥类似于其哺乳动物同源物的作用，从而调节水稻的细胞死亡和免疫，揭示了甘露糖结合凝集素在植物中的功能。
