BLUE LIGHT-INDUCED PHOSPHORYLATION OF A PLASMA MEMBRANE-ASSOCIATED PROTEIN IN ZEA-MAYS L
BLUE LIGHT-INDUCED PHOSPHORYLATION OF A PLASMA MEMBRANE-ASSOCIATED PROTEIN IN ZEA-MAYS L
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DOI：
10.1104/pp.102.4.1211
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发表时间：
1993-08-01
期刊：
影响因子：
7.4
通讯作者：
BRIGGS, WR
中科院分区：
文献类型：
--
作者：
PALMER, JM;SHORT, TW;BRIGGS, WR
蓝光在高等植物中引起多种光形态形成反应，其中包括向光弯曲，即幼苗向单向光源弯曲。在黑暗生长的玉米（Zea mays L.）幼苗胚囊中，蓝光诱导一个114-kD蛋白的快速磷酸化，其影响水平足以刺激向光弯曲。在体内，在32Pi中预孵育的胚芽鞘尖端或在体外添加了[γ - p -32]ATP的分离膜中，可以检测到对蓝光的磷酸化反应。在感应光脉冲后的2分钟内，磷酸化在体外达到最大水平，但在前15秒内发生实质性标记。即使在没有外源性ATP的情况下，在体外蓝光刺激下，离体膜仍能保持激活数分钟。114-kD蛋白的磷酸氨基酸分析检测到磷丝氨酸和微量磷苏氨酸。参与体外磷酸化蛋白的激酶不依赖于钙。114-kD蛋白本身具有明显的ATP结合位点，通过与不可水解的类似物5′-对氟磺酰基苯甲酰腺苷孵育检测。这一结果表明，在蓝光作用下磷酸化的114-kD蛋白也可能具有激酶活性。
Blue light induces a variety of photomorphogenic responses in higher plants, among them phototropic curvature, the bending of seedlings toward a unidirectional light source. In dark-grown coleoptiles of maize (Zea mays L.) seedlings, blue light induces rapid phosphorylation of a 114-kD protein at fluence levels that are sufficient to stimulate phototropic curvature. Phosphorylation in response to blue light can be detected in vivo in coleoptile tips preincubated in 32Pi or in vitro in isolated membranes supplemented with [gamma-P-32]ATP. Phosphorylation reaches a maximum level in vitro within 2 min following an inductive light pulse, but substantial labeling occurs within the first 15 s. Isolated membranes remain activated for several minutes following an in vitro blue light stimulus, even in the absence of exogenous ATP. Phosphoamino acid analysis of the 114-kD protein detected phosphoserine and a trace of phosphothreonine. The kinase involved in phosphorylating the protein in vitro is not dependent on calcium. The 114-kD protein itself has an apparent binding site for ATP, detected by incubating with the nonhydrolyzable analog, 5'-p-fluorosulfonyl-benzoyladenosine. This result suggests that the 114-kD protein, which becomes phosphorylated in response to blue light, may also be capable of kinase activity.