Olsson A, Svennelid F, Ek B, Sommarin M, Larsson C
Department of Plant Biochemistry, Lund University, P.O. Box 117, SE-221 00 Lund, Sweden.
Plant Physiol. 1998 Oct;118(2):551-5. doi: 10.1104/pp.118.2.551.
We have isolated the plasma membrane H+-ATPase in a phosphorylated form from spinach (Spinacia oleracea L.) leaf tissue incubated with fusicoccin, a fungal toxin that induces irreversible binding of 14-3-3 protein to the C terminus of the H+-ATPase, thus activating H+ pumping. We have identified threonine-948, the second residue from the C-terminal end of the H+-ATPase, as the phosphorylated amino acid. Turnover of the phosphate group of phosphothreonine-948 was inhibited by 14-3-3 binding, suggesting that this residue may form part of a binding motif for 14-3-3. This is the first identification to our knowledge of an in vivo phosphorylation site in the plant plasma membrane H+-ATPase.
我们从用藤霉素孵育的菠菜（Spinacia oleracea L.）叶片组织中分离出了磷酸化形式的质膜H⁺-ATP酶。藤霉素是一种真菌毒素，可诱导14-3-3蛋白与H⁺-ATP酶的C末端不可逆结合，从而激活H⁺泵浦。我们已确定H⁺-ATP酶C末端第二个残基苏氨酸-948为磷酸化氨基酸。14-3-3的结合抑制了磷酸苏氨酸-948磷酸基团的周转，这表明该残基可能构成14-3-3结合基序的一部分。据我们所知，这是首次鉴定出植物质膜H⁺-ATP酶的体内磷酸化位点。
