Calcium-dependent protein kinases responsible for the phosphorylation of a bZIP transcription factor FD crucial for the florigen complex formation.
Calcium-dependent protein kinases responsible for the phosphorylation of a bZIP transcription factor FD crucial for the florigen complex formation.
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DOI：
10.1038/srep08341
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发表时间：
2015-02-09
影响因子：
4.6
通讯作者：
Araki T
中科院分区：
文献类型：
--
作者：
Kawamoto N;Sasabe M;Endo M;Machida Y;Araki T
适当的开花时间对于繁殖成功至关重要，并且必然涉及复杂的遗传调控网络。一种称为成花素的移动花信号是该过程中的关键分子，而 FLOWERING LOCUS T (FT) 蛋白是其在拟南芥中的主要成分。 FT 在叶子中产生，但促进茎尖的花转变，在那里它与碱性区域/亮氨酸拉链 (bZIP) 转录因子 FD 形成复合物。成花素复合物的形成取决于 FD 的磷酸化；然而，迄今为止，尚未确定负责的蛋白激酶。在这项研究中，我们从花过渡期周围的植物芽尖中制备了蛋白质提取物，并检测到磷酸化 FD 282 位苏氨酸残基 (FD T282) 的蛋白激酶活性，该残基是通过 14-3-3 与 FT 形成复合物的关键残基。激酶活性是钙依赖性的。随后的生化、细胞和遗传分析表明，三种钙依赖性蛋白激酶 (CDPK) 可有效磷酸化 FD T282。其中两个（CPK6 和 CPK33）在茎尖分生组织中表达，并直接与 FD 相互作用，表明它们具有冗余功能。一个 CDPK (CPK33) 功能的丧失导致微弱但显着的晚花表型。
Appropriate timing of flowering is critical for reproductive success and necessarily involves complex genetic regulatory networks. A mobile floral signal, called florigen, is a key molecule in this process, and FLOWERING LOCUS T (FT) protein is its major component in Arabidopsis. FT is produced in leaves, but promotes the floral transition in the shoot apex, where it forms a complex with a basic region/leucine-zipper (bZIP) transcription factor, FD. Formation of the florigen complex depends on the supposed phosphorylation of FD; hitherto, however, the responsible protein kinase(s) have not been identified. In this study, we prepared protein extracts from shoot apices of plants around the floral transition, and detected a protein kinase activity that phosphorylates a threonine residue at position 282 of FD (FD T282), which is a crucial residue for the complex formation with FT via 14-3-3. The kinase activity was calcium-dependent. Subsequent biochemical, cellular, and genetic analyses showed that three calcium-dependent protein kinases (CDPKs) efficiently phosphorylate FD T282. Two of them (CPK6 and CPK33) are expressed in shoot apical meristem and directly interact with FD, suggesting they have redundant functions. The loss of function of one CDPK (CPK33) resulted in a weak but significant late-flowering phenotype.
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影响因子：
11.6
作者：
Hanano, Shigeru;Goto, Koji
通讯作者：
Goto, Koji
影响因子：
7.2
作者：
Huang, Nien-Chen;Jane, Wann-Neng;Yu, Tien-Shin
通讯作者：
Yu, Tien-Shin
DOI：
10.1073/pnas.0505667103
发表时间：
2006-02-07
影响因子：
11.1
作者：
Furihata, T;Maruyama, K;Yamaguchi-Shinozaki, K
通讯作者：
Yamaguchi-Shinozaki, K
影响因子：
11.6
作者：
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通讯作者：
Lucas, William J.
影响因子：
7.2
作者：
Benlloch, Reyes;Kim, Min Chul;Nilsson, Ove
通讯作者：
Nilsson, Ove