The Arabidopsis Rab5 homologs Rha1 and Ara7 localize to the prevacuolar compartment
The Arabidopsis Rab5 homologs Rha1 and Ara7 localize to the prevacuolar compartment
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DOI：
10.1093/pcp/pch142
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发表时间：
2004-09-01
影响因子：
4.9
通讯作者：
Hwang, I
中科院分区：
文献类型：
--
作者：
Lee, GJ;Sohn, EJ;Hwang, I
Rha 1是拟南芥Rab 5的同源基因，在植物细胞液泡运输中起着关键作用。在这项研究中，我们调查了Rha 1和Ara 7，两个拟南芥蛋白，具有高度相似的氨基酸序列同源性Rab 5在动物细胞中的本地化。Ara 7和Rha 1在拟南芥原生质体中瞬时表达为绿色荧光蛋白（绿色荧光蛋白）或小表位标记的形式时，均呈现点状染色模式并共定位。在原生质体中，瞬时表达的Pha 1和Ara 7与AtPEP 12 p和VSRAt-1共定位，这两种蛋白质已知存在于前液泡室（PVC）。此外，内源性Rha 1也给出了点状染色模式，并与AtPEP 12 p共定位于PVC。第一和第二GTP结合基序的突变改变了GFP的定位：Rha 1 [S24 N]在细胞质中，Rha 1 [Q69 L]在中央液泡的液泡膜中。此外，在效应域和异戊烯化位点的突变抑制Rha 1的膜缔合。基于这些结果，我们建议，Rha 1和Ara 7本地化的PVC和GTP结合基序以及效应域是重要的本地化Rha 1的PVC。
Rha1, an Arabidopsis Rab5 homolog, plays a critical role in vacuolar trafficking in plant cells. In this study, we investigated the localization of Rha1 and Ara7, two Arabidopsis proteins that have highly similar amino acid sequence homology to Rab5 in animal cells. Both Ara7 and Rha1 gave a punctate staining pattern and colocalized when transiently expressed as GFP- (green fluorescent protein) or small epitope-tagged forms in Arabidopsis protoplasts. In protoplasts, transiently expressed Pha1 and Ara7 colocalized with AtPEP12p and VSRAt-1, two proteins that are known to be present at the prevacuolar compartment (PVC). Furthermore, endogenous Rha1 also gave a punctate staining pattern and colocalized with AtPEP12p to the PVC. Mutations in the first and second GTP-binding motifs alter the localizations of GFP:Rha1[S24N] in the cytosol and Rha1[Q69L] in the tonoplast of the central vacuole. Also, mutations in the effector domain and the prenylation site inhibit membrane association of Rha1. Based on these results, we propose that Rha1 and Ara7 localize to the PVC and that GTP-binding motifs as well as the effector domain are important for localization of Rha1 to the PVC.