The GRV2/RME-8 protein of Arabidopsis functions in the late endocytic pathway and is required for vacuolar membrane flow |
| |
Authors: | Silady Rebecca A Ehrhardt David W Jackson Karen Faulkner Christine Oparka Karl Somerville Chris R |
| |
Institution: | Department of Biological Sciences, Stanford University, Stanford, CA 94305, USA. |
| |
Abstract: | The gravitropism defective 2 (grv2) mutants of Arabidopsis thaliana were previously characterized as exhibiting shoot agravitropism resulting from mutations in a homolog of the Caenorhabditis elegans RECEPTOR-MEDIATED ENDOCYTOSIS-8 (RME-8) gene, which is required in C. elegans for endocytosis. A fluorescent protein fusion to the GRV2 protein localized to endosomes in transgenic plants, and vacuolar morphology was altered in grv2 mutants. A defect in vacuolar membrane dynamics provides a mechanistic explanation for the gravitropic defect, and may also account for the presence of an enlarged vacuole in early embryos, together with a nutrient requirement during seedling establishment. The GRV2-positive endosomes were sensitive to Wortmannin but not brefeldin A (BFA), consistent with GRV2 operating late in the endocytic pathway, prior to delivery of vesicles to the central vacuole. The specific enlargement of GRV2:YFP structures by Wortmannin, together with biochemical data showing that GRV2 co-fractionates with pre-vacuolar markers such as PEP12/SYP21, leads us to conclude that in plants GRV2/RME-8 functions in vesicle trafficking from the multivesicular body/pre-vacuolar compartment to the lytic vacuole. |
| |
Keywords: | prevacuole late endosome vesicle tonoplast RME-8 endocytosis |
本文献已被 PubMed 等数据库收录! |
|