Inoue K, Wada Y, Nishimura M, Hara-Nishimura I
Department of Cell Biology, National Institute for Basic Biology, Okazaki, Japan.
Plant Cell Physiol. 1997 Mar;38(3):366-70. doi: 10.1093/oxfordjournals.pcp.a029176.
Two tonoplast intrinsic proteins (TIP) of pumpkin seeds, pMP23 and MP28, were expressed in yeast cells under control of the GAL1 promoter, and the subcellular localization of the proteins was analyzed. The pMP23 and MP28 stably accumulated in the yeast vacuolar membrane when the proteins were expressed in the proteinase A-deficient strain (pep4), which lacks the activities of vacuolar proteases. However, pMP23 and MP28 did not accumulate in the wild-type strain; the expressed pMP23 and MP28 were degraded in a proteinase A-dependent manner. These results indicate that pMP23 and MP28 are transported to the vacuolar membrane when expressed in yeast.
南瓜种子的两种液泡膜内在蛋白（TIP），即pMP23和MP28，在GAL1启动子的控制下在酵母细胞中表达，并对这些蛋白的亚细胞定位进行了分析。当在缺乏液泡蛋白酶活性的蛋白酶A缺陷型菌株（pep4）中表达时，pMP23和MP28稳定地积累在酵母液泡膜中。然而，pMP23和MP28在野生型菌株中不积累；所表达的pMP23和MP28以蛋白酶A依赖的方式被降解。这些结果表明，pMP23和MP28在酵母中表达时被转运到液泡膜。
