Alvim Kamei Claire Lessa, Boruc Joanna, Vandepoele Klaas, Van den Daele Hilde, Maes Sara, Russinova Eugenia, Inzé Dirk, De Veylder Lieven
Instituto de Bioquímica Médica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ 21941-590, Brazil.
Plant Physiol. 2008 Aug;147(4):1735-49. doi: 10.1104/pp.108.122226. Epub 2008 Jun 26.
Prenylated Rab acceptor 1 (PRA1) domain proteins are small transmembrane proteins that regulate vesicle trafficking as receptors of Rab GTPases and the vacuolar soluble N-ethylmaleimide-sensitive factor attachment receptor protein VAMP2. However, little is known about PRA1 family members in plants. Sequence analysis revealed that higher plants, compared with animals and primitive plants, possess an expanded family of PRA1 domain-containing proteins. The Arabidopsis (Arabidopsis thaliana) PRA1 (AtPRA1) proteins were found to homodimerize and heterodimerize in a manner corresponding to their phylogenetic distribution. Different AtPRA1 family members displayed distinct expression patterns, with a preference for vascular cells and expanding or developing tissues. AtPRA1 genes were significantly coexpressed with Rab GTPases and genes encoding vesicle transport proteins, suggesting an involvement in the vesicle trafficking process similar to that of their animal counterparts. Correspondingly, AtPRA1 proteins were localized in the endoplasmic reticulum, Golgi apparatus, and endosomes/prevacuolar compartments, hinting at a function in both secretory and endocytic intracellular trafficking pathways. Taken together, our data reveal a high functional diversity of AtPRA1 proteins, probably dealing with the various demands of the complex trafficking system.
异戊烯化Rab受体1（PRA1）结构域蛋白是一类小的跨膜蛋白，作为Rab GTP酶和液泡可溶性N - 乙基马来酰亚胺敏感因子附着受体蛋白VAMP2的受体，调节囊泡运输。然而，关于植物中的PRA1家族成员知之甚少。序列分析表明，与动物和原始植物相比，高等植物拥有一个扩展的含PRA1结构域蛋白家族。研究发现，拟南芥（Arabidopsis thaliana）的PRA1（AtPRA1）蛋白以与其系统发育分布相对应的方式进行同二聚化和异二聚化。不同的AtPRA1家族成员表现出不同的表达模式，偏好于维管细胞以及正在扩展或发育的组织。AtPRA1基因与Rab GTP酶和编码囊泡运输蛋白的基因显著共表达，表明其参与了与动物对应物类似的囊泡运输过程。相应地，AtPRA1蛋白定位于内质网、高尔基体以及内体/前液泡区室，提示其在分泌和内吞细胞内运输途径中均发挥作用。综上所述，我们的数据揭示了AtPRA1蛋白具有高度的功能多样性，可能应对复杂运输系统的各种需求。
