| Autor: |
Silady, Rebecca A., Ehrhardt, David W., Jackson, Karen, Faulkner, Christine, Oparka, Karl, Somerville, Chris R. |
| Předmět: |
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| Zdroj: |
Plant Journal; Jan2008, Vol. 53 Issue 1, p29-41, 13p, 1 Black and White Photograph, 7 Diagrams, 3 Charts, 1 Graph |
| Abstrakt: |
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. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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