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. © 2006 The Authors.
Kohorn, Bruce D.; Kobayashi, Masaru; Johansen, Sue; Riese, Jeff; Huang, Li Fen; Koch, Karen; Fu, Sarita; Dotson, Anjali; and Byers, Nicole, "An Arabidopsis cell wall-associated kinase required for invertase activity and cell growth" (2006). Biology Faculty Publications. 168.