Leube M P, Grill E, Amrhein N
Institut für Pflanzenwissenschaften, Eidgenössische Technische Hochschule Zürich, Switzerland.
FEBS Lett. 1998 Mar 6;424(1-2):100-4. doi: 10.1016/s0014-5793(98)00149-5.
The plant hormone abscisic acid (ABA) mediates various responses such as stomatal closure, maintenance of seed dormancy, and inhibition of plant growth. All three responses are regulated by the ABI1 gene product. The ABI1 protein (ABI1p) has been characterized as a protein serine/threonine phosphatase of type 2C that is highly affected in its activity by changes in the proton and magnesium ion concentrations. In the ABA-insensitive mutant abi1 of Arabidopsis thaliana a single amino acid exchange in the primary structure results in both a dominant insensitive phenotype and a strongly reduced protein phosphatase activity in vitro by possibly impairing metal ion coordination.
植物激素脱落酸（ABA）介导多种反应，如气孔关闭、种子休眠维持以及植物生长抑制。所有这三种反应均受ABI1基因产物调控。ABI1蛋白（ABI1p）已被鉴定为2C型蛋白丝氨酸/苏氨酸磷酸酶，其活性受质子和镁离子浓度变化的显著影响。在拟南芥的ABA不敏感突变体abi1中，一级结构中的单个氨基酸交换导致显性不敏感表型以及体外蛋白磷酸酶活性大幅降低，这可能是由于损害了金属离子配位。
