title: Arabidopsis FAB1A/B is possibly involved in the recycling of auxin transporters.
abstract: Fab1/PIKfyve produces Phosphatidylinositol 3,5-bisphosphate (PtdIns (3,5) P2) from Phosphatidylinositol 3-phosphate (PtdIns 3-P), and is involved not only in vacuole/lysosome homeostasis, but also in transporting various proteins to the vacuole or recycling proteins on the plasma membrane (PM) through the use of endosomes in a variety of eukaryotic cells. We previously demonstrated that Arabidopsis FAB1A/B functions as PtdIns 3,5-kinase in both Arabidopsis and fission yeast and plays a key role in vacuolar acidification and endocytosis. Although the conditional FAB1A/B knockdown mutant revealed an auxin-resistant phenotype to a membrane impermeable auxin, 2,4-dichlorophenoxyacetic acid (2,4-D), the mutant did not exhibit this phenotype to a membrane-permeable artificial auxin, naphthalene 1-acetic acid (NAA). The difference in the sensitivities to 2,4-D and NAA is similar to those of the auxin-resistant mutants such as aux1. Taken together, these results suggest that impairment of the function of Arabidopsis FAB1A/B might cause a defect in the membrane recycling capabilities of the auxin transporters and inhibit proper auxin transport into the cells in Arabidopsis.
authors.affiliation: Graduate School of Biostudies, Kyoto University, Kyoto, Japan. mhsato@kpu.ac.jp
authors.forename: Tomoko
authors.initials: T
authors.lastname: Hirano
authors.forename: Masa H
authors.initials: MH
authors.lastname: Sato
mesh_terms: D015084:2,4-Dichlorophenoxyacetic Acid / Q000494:pharmacology; D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D001692:Biological Transport; D007210:Indoleacetic Acids / Q000494:pharmacology; D026901:Membrane Transport Proteins / Q000235:genetics / Q000378:metabolism*; D009280:Naphthaleneacetic Acids / Q000494:pharmacology; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified / Q000187:drug effects / Q000235:genetics / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; D007210:Indoleacetic Acids; D026901:Membrane Transport Proteins; D009280:Naphthaleneacetic Acids; D015084:2,4-Dichlorophenoxyacetic Acid; C547216:FAB1A protein, Arabidopsis; C547217:FAB1B protein, Arabidopsis; D017853:Phosphotransferases (Alcohol Group Acceptor)