Glycosylation defects activate filamentous growth Kss1 MAPK and inhibit osmoregulatory Hog1 MAPK
Glycosylation defects activate filamentous growth Kss1 MAPK and inhibit osmoregulatory Hog1 MAPK
复制标题
DOI：
10.1038/emboj.2009.104
复制
发表时间：
2009-05-20
期刊：
影响因子：
11.4
通讯作者：
Saito, Haruo
中科院分区：
文献类型：
--
作者：
Yang, Hui-Yu;Tatebayashi, Kazuo;Saito, Haruo
酵母丝状生长（FG）MAP激酶（MAPK）途径在营养不良条件下被激活。我们发现，FG-特异性KSS 1 MAPK被激活的O-糖基化缺陷的组合所造成的破坏的基因编码的蛋白质O-甘露糖基转移酶Pmt 4，和N-糖基化缺陷引起的衣霉素。O-糖基化的膜蛋白Msb 2和Opy 2都是激活FG MAPK途径所必需的，但只有Msb 2的糖基化缺陷才能激活FG MAPK途径。虽然高渗透压甘油（HOG）MAPK通路和FG MAPK通路几乎共享整个上游信号传导机制，但高渗透压应激仅激活HOG特异性Hog 1 MAPK。相反，我们现在表明，糖基化缺陷激活Kss 1，而激活Kss 1和Ptp 2酪氨酸磷酸酶抑制Hog 1。然而，在缺乏Kss 1或Ptp 2的情况下，糖基化缺陷激活Hog 1。当Hog 1被ptp 2突变体中的糖基化缺陷激活时，Hog 1抑制Kss 1的激活。因此，Kss 1和Hog 1之间的相互抑制环仅允许这些MAPK中的一个或另一个在各种应激条件下被稳定地激活。The EMBO Journal（2009）28，1380-1391. doi：10.1038/doj.2009.104; 2009年4月16日在线发布
The yeast filamentous growth (FG) MAP kinase (MAPK) pathway is activated under poor nutritional conditions. We found that the FG-specific Kss1 MAPK is activated by a combination of an O-glycosylation defect caused by disruption of the gene encoding the protein O-mannosyl-transferase Pmt4, and an N-glycosylation defect induced by tunicamycin. The O-glycosylated membrane proteins Msb2 and Opy2 are both essential for activating the FG MAPK pathway, but only defective glycosylation of Msb2 activates the FG MAPK pathway. Although the osmoregulatory HOG (high osmolarity glycerol) MAPK pathway and the FG MAPK pathway share almost the entire upstream signalling machinery, osmostress activates only the HOG-specific Hog1 MAPK. Conversely, we now show that glycosylation defects activate only Kss1, while activated Kss1 and the Ptp2 tyrosine phosphatase inhibit Hog1. In the absence of Kss1 or Ptp2, however, glycosylation defects activate Hog1. When Hog1 is activated by glycosylation defects in ptp2 mutant, Kss1 activation is suppressed by Hog1. Thus, the reciprocal inhibitory loop between Kss1 and Hog1 allows only one or the other of these MAPKs to be stably activated under various stress conditions. The EMBO Journal (2009) 28, 1380-1391. doi:10.1038/emboj.2009.104; Published online 16 April 2009