Ueda Takashi, Uemura Tomohiro, Sato Masa H, Nakano Akihiko
Department of Biological Sciences, Graduate School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
Plant J. 2004 Dec;40(5):783-9. doi: 10.1111/j.1365-313X.2004.02249.x.
Endocytosis plays an important role in plant physiology, but how endocytic organelles are organized remains unknown. We present the evidence that endosomes are functionally differentiated in Arabidopsis cells. Two types of Rab5-related GTPases are localized on distinct population of endosomes in a partially overlapping manner. Ara7 and Rha1 are on an early type of endosomes with AtVamp727, where recycling of plasma membrane proteins occurs. In contrast, the plant-unique Rab5, Ara6, resides on distinct endosomes with the prevacuolar SNAREs. Partially overlapping localization of Ara6 and Ara7/Rha1 with reciprocal gradients suggests maturation of endosomes from one to the other.
内吞作用在植物生理学中起着重要作用，但内吞细胞器是如何组织的仍不清楚。我们提供证据表明，拟南芥细胞中的内体在功能上是有差异的。两种与Rab5相关的小GTP酶以部分重叠的方式定位于不同群体的内体上。Ara7和Rha1与AtVamp727位于早期类型的内体上，质膜蛋白在此进行循环利用。相比之下，植物特有的Rab5，即Ara6，与液泡前体SNARE蛋白位于不同的内体上。Ara6与Ara7/Rha1的部分重叠定位及相反的梯度表明内体从一种类型向另一种类型的成熟过程。
