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An Arabidopsis cell wall-associated kinase required for invertase activity and cell growth
Date: 2006-04-01
Creator: Bruce D. Kohorn, Masaru Kobayashi, Sue Johansen, Jeff Riese, Li Fen, Huang, Karen Koch, Sarita Fu, Anjali Dotson, Nicole Byers
Access: Open access
- 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.
The cell wall-associated kinases, WAKs, as pectin receptors
Date: 2012-05-08
Creator: Bruce D. Kohorn, Susan L. Kohorn
Access: Open access
- The wall-associated kinases, WAKs, are encoded by five highly similar genes clustered in a 30-kb locus in Arabidopsis. These receptor-like proteins contain a cytoplasmic serine threonine kinase, a transmembrane domain, and a less conserved region that is bound to the cell wall and contains a series of epidermal growth factor repeats. Evidence is emerging that WAKs serve as pectin receptors, for both short oligogalacturonic acid fragments generated during pathogen exposure or wounding, and for longer pectins resident in native cell walls. This ability to bind and respond to several types of pectins correlates with a demonstrated role for WAKs in both the pathogen response and cell expansion during plant development. © 2012 Kohorn and Kohorn.