Kohorn Bruce D, Kobayashi Masaru, Johansen Sue, Riese Jeff, Huang Li-Fen, Koch Karen, Fu Sarita, Dotson Anjali, Byers Nicole
Department of Biology, Bowdoin College, Brunswick, ME 04011, USA.
Plant J. 2006 Apr;46(2):307-16. doi: 10.1111/j.1365-313X.2006.02695.x.
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.
壁相关激酶（WAK）是一个由五种蛋白质组成的家族，其包含可与细胞壁的果胶分子相连的细胞外结构域，跨越质膜并具有细胞质丝氨酸/苏氨酸激酶结构域。先前的研究表明，WAK蛋白水平的降低会导致细胞扩张丧失，这表明这些类受体蛋白在细胞形状形成中发挥作用。本文表明，单个wak2突变体在幼苗生长方面表现出对糖和盐的依赖性。该突变还降低了液泡转化酶的表达和活性，而液泡转化酶通常是膨压和细胞扩张的关键因素。因此，WAK可能提供一种分子机制，将细胞壁感知（通过果胶附着）与溶质代谢调节联系起来，而溶质代谢已知参与生长细胞中膨压的维持。
