CLV3 is localized to the extracellular space, where it activates the Arabidopsis CLAVATA stem cell signaling pathway.
Plant growth and development depends on the activity of a continuously replenished pool of stem cells within the shoot apical meristem to supply cells for organogenesis. In Arabidopsis, the stem cell-specific protein CLAVATA3 (CLV3) acts cell nonautonomously to restrict the size of the stem cell population, but the hypothesis that CLV3 acts as an extracellular signaling molecule has not been tested. We used genetic and immunological assays to show that CLV3 localizes to the apoplast and that export to the extracellular space is required for its function in activating the CLV1/CLV2 receptor complex. Apoplastic localization allows CLV3 to signal from the stem cell population to the organizing center in the underlying cells.
Rojo
Enrique
E
Department of Botany and Plant Sciences and Center for Plant Cell Biology, University of California, Riverside, California 92521, USA.
Sharma
Vijay K
VK
Kovaleva
Valentina
V
Raikhel
Natasha V
NV
Fletcher
Jennifer C
JC
D017360:Arabidopsis / Q000235:genetics* / Q000254:growth & development; D029681:Arabidopsis Proteins; D002454:Cell Differentiation / Q000235:genetics; D002455:Cell Division / Q000235:genetics; D002473:Cell Wall / Q000378:metabolism; D005110:Extracellular Space / Q000378:metabolism; D008565:Membrane Proteins / Q000235:genetics*; D018519:Meristem / Q000235:genetics / Q000254:growth & development; D010940:Plant Proteins / Q000235:genetics*; D018520:Plant Shoots / Q000235:genetics / Q000254:growth & development; D017346:Protein Serine-Threonine Kinases; D020794:Receptor Protein-Tyrosine Kinases / Q000235:genetics*; D015398:Signal Transduction / Q000235:genetics*; D014617:Vacuoles / Q000378:metabolism
C118167:AT2G27250 protein, Arabidopsis; D029681:Arabidopsis Proteins; C401621:CLV2 protein, Arabidopsis; D008565:Membrane Proteins; D010940:Plant Proteins; D020794:Receptor Protein-Tyrosine Kinases; C118166:CLV1 protein, Arabidopsis; D017346:Protein Serine-Threonine Kinases