Cytoplasm localization of aminopeptidase M1 and its functional activity in root hair cells and BY-2 cells.
Aminopeptidase M1 (APM1) was the first M1 metallopeptidase family member identified in Arabidopsis, isolated by its affinity for the auxin transport inhibitor N-1-naphthylphthalamic acid (NPA). A loss-of-function mutation showed various developmental defects in cell division and auxin transport. APM1 was shown to be localized in endomembrane structures, the cytoplasm, and the plasma membrane. These previous results suggested that APM1 has diverse functional roles in different cell and tissue types. Here we report that APM1 localized to the cytoplasm, and its over-expression in the root hair cell caused longer root hair phenotypes. Treatment of aminopeptidase inhibitors caused internalization of auxin efflux PIN-FORMED proteins in root hair cells and suppressed short root hair phenotype of PIN3 overexpression line (PIN3ox). APM1 also localized to the cytoplasm in tobacco BY-2 cells, its over-expression had little effect on auxin transport in these cells.
Department of Biological Sciences and Plant Genomics and Breeding Institute, Seoul National University, 599 Gwanak-ro, Gwanak-gu, Seoul 151-742, South Korea.
Ok Ran
OR
Lee
Hyung-Taeg
HT
Cho
D000626:Aminopeptidases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D017360:Arabidopsis / Q000166:cytology / Q000201:enzymology*; D029681:Arabidopsis Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism* / Q000502:physiology; D001426:Bacterial Proteins / Q000096:biosynthesis / Q000235:genetics; D003593:Cytoplasm / Q000201:enzymology*; D049452:Green Fluorescent Proteins / Q000096:biosynthesis / Q000235:genetics; D007210:Indoleacetic Acids / Q000378:metabolism; D008164:Luminescent Proteins / Q000096:biosynthesis / Q000235:genetics; D008565:Membrane Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism*; D026901:Membrane Transport Proteins / Q000378:metabolism / Q000502:physiology; D009928:Organ Specificity; D018517:Plant Roots / Q000033:anatomy & histology / Q000166:cytology* / Q000254:growth & development; D011480:Protease Inhibitors / Q000494:pharmacology; D021381:Protein Transport; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000235:genetics; D014026:Nicotiana / Q000166:cytology* / Q000378:metabolism
D029681:Arabidopsis Proteins; D001426:Bacterial Proteins; D007210:Indoleacetic Acids; D008164:Luminescent Proteins; D008565:Membrane Proteins; D026901:Membrane Transport Proteins; C116363:PIN1 protein, Arabidopsis; D011480:Protease Inhibitors; D011993:Recombinant Fusion Proteins; C054562:yellow fluorescent protein, Bacteria; D049452:Green Fluorescent Proteins; C456412:ATAPP1 protein, Arabidopsis; D000626:Aminopeptidases