Endosomal signaling of plant steroid receptor kinase BRI1.
The LRR receptor serine/threonine kinases are a major eukaryotic receptor family, for which the central regulatory mechanism of endosomal trafficking remains largely unadressed. We show that the steroid receptor BRI1 localizes to both plasma membrane and early endosomal compartments, even when observed at low, endogenous expression levels, and that its localization and turnover are independent of ligand. However, increasing endosomal localization of BRI1 enhances activation of the pathway and genomic responses. Our data indicate distinct signaling and trafficking mechanisms within this receptor class and show that the use of endosomes as signaling compartments is an unexpectedly broad phenomenon in eukaryotes.
Geldner
Niko
N
Plant Biology Laboratory, The Salk Institute, La Jolla, CA 92037, USA.
Hyman
Derek L
DL
Wang
Xuelu
X
Schumacher
Karin
K
Chory
Joanne
J
D017360:Arabidopsis / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D002478:Cells, Cultured; D004705:Endocytosis / Q000502:physiology; D011992:Endosomes / Q000378:metabolism / Q000502:physiology*; D049452:Green Fluorescent Proteins / Q000235:genetics; D010940:Plant Proteins / Q000502:physiology; D030821:Plants, Genetically Modified; D011494:Protein Kinases / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D021381:Protein Transport / Q000502:physiology; D015398:Signal Transduction / Q000502:physiology*; D014018:Tissue Distribution; D014162:Transfection
D029681:Arabidopsis Proteins; D010940:Plant Proteins; D049452:Green Fluorescent Proteins; D011494:Protein Kinases; C108270:BRI1 protein, Arabidopsis