An Arabidopsis cell wall-associated kinase required for invertase activity and cell growth.
The wall-associated kinases (WAK), a family of five proteins that contain extracellular domains that can be linked to pectin molecules of the cell wall, span the plasma membrane and have a cytoplasmic serine/threonine kinase domain. Previous work has shown that a reduction in WAK protein levels leads to a loss of cell expansion, indicating that these receptor-like proteins have a role in cell shape formation. Here it is shown that a single wak2 mutation exhibits a dependence on sugars and salts for seedling growth. This mutation also reduces the expression and activity of vacuolar invertase, often a key factor in turgor and expansion. WAKs may thus provide a molecular mechanism linking cell wall sensing (via pectin attachment) to regulation of solute metabolism, which in turn is known to be involved in turgor maintenance in growing cells.
Kohorn
Bruce D
BD
Department of Biology, Bowdoin College, Brunswick, ME 04011, USA. bkohorn@bowdoin.edu
Kobayashi
Masaru
M
Johansen
Sue
S
Riese
Jeff
J
Huang
Li-Fen
LF
Koch
Karen
K
Fu
Sarita
S
Dotson
Anjali
A
Byers
Nicole
N
D017360:Arabidopsis / Q000201:enzymology* / Q000254:growth & development; D029681:Arabidopsis Proteins / Q000378:metabolism; D002473:Cell Wall / Q000201:enzymology*; D010368:Pectins / Q000378:metabolism; D010770:Phosphotransferases / Q000378:metabolism*; D043324:beta-Fructofuranosidase / Q000378:metabolism*
D029681:Arabidopsis Proteins; D010368:Pectins; D010770:Phosphotransferases; D043324:beta-Fructofuranosidase