title: Distinct localization of two closely related Ypt3/Rab11 proteins on the trafficking pathway in higher plants.
abstract: Ypt/Rab proteins are Ras-related small GTPases that act on the intracellular membrane through the trafficking pathway, and their function depends on their localization. Approximately 25 genes encoding Ypt3/Rab11-related proteins exist in Arabidopsis, but the reason for the presence of many genes in plants remains unclear. Pea Pra2 and Pra3, members of Ypt3/Rab11, are closely related proteins. Because possible orthologs are conserved among dicots, they can be studied to determine their possible localization. Biochemical analysis revealed that these proteins were localized on distinct membranes in pea. Furthermore, using green fluorescent protein-Pra2 and green fluorescent protein-Pra3 fusion proteins, we demonstrated that these proteins are distinctively localized on the trafficking pathway in tobacco Bright Yellow 2 cells. Pra2 was predominantly localized on Golgi stacks and endosomes, which did not support the localization of Pra2 on the endoplasmic reticulum (Kang, J. G., Yun, J., Kim, D. H., Chung, K. S., Fujioka, S., Kim, J. I., Dae, H. W., Yoshida, S., Takatsuto, S., Song, P. S., and Park, C. M. (2001) Cell 105, 625--636). In contrast, Pra3 was likely to be localized on the trans-Golgi network and/or the prevacuolar compartment. We concluded that Pra2 and Pra3 proteins are distinctively localized on the trafficking pathway. This finding suggests that functional diversification takes place in the plant Ypt3/Rab11 family.
authors.affiliation: Laboratory of Plant Molecular Biology, Graduate School of Agricultural Sciences, Nagoya University, Nagoya 464-8601, Japan.
authors.forename: Takehito
authors.initials: T
authors.lastname: Inaba
authors.forename: Yukio
authors.initials: Y
authors.lastname: Nagano
authors.forename: Takeshi
authors.initials: T
authors.lastname: Nagasaki
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Sasaki
mesh_terms: D001692:Biological Transport; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism; D004705:Endocytosis; D005656:Fungal Proteins / Q000032:analysis; D006056:Golgi Apparatus / Q000737:chemistry; D015636:Magnesium Chloride / Q000494:pharmacology; D010940:Plant Proteins; D029702:Schizosaccharomyces pombe Proteins; D014026:Nicotiana / Q000737:chemistry; D020691:rab GTP-Binding Proteins / Q000032:analysis*; D000099193:rab11 GTP-Binding Proteins
chemical_list: D003577:Cytochrome P-450 Enzyme System; D005656:Fungal Proteins; D015636:Magnesium Chloride; D010940:Plant Proteins; D029702:Schizosaccharomyces pombe Proteins; D020691:rab GTP-Binding Proteins; D000099193:rab11 GTP-Binding Proteins; C429308:DDWF1 protein, Pisum sativum; C094511:PRA3 protein, Pisum sativum; C075976:ypt3 protein, S pombe; C094510:PRA2 protein, Pisum sativum