A novel RNA binding protein affects rbcL gene expression and is specific to bundle sheath chloroplasts in C4 plants.
A novel RNA binding protein affects rbcL gene expression and is specific to bundle sheath chloroplasts in C4 plants.
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DOI：
10.1186/1471-2229-13-138
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发表时间：
2013-09-22
影响因子：
5.3
通讯作者：
Berry JO
中科院分区：
文献类型：
--
作者：
Bowman SM;Patel M;Yerramsetty P;Mure CM;Zielinski AM;Bruenn JA;Berry JO
利用高效 C4 光合作用途径的植物通常具有 kranz 型叶子解剖结构，由两种形态和功能不同的光合细胞类型组成，即束鞘 (BS) 和叶肉 (M) 细胞。这两种细胞类型差异表达 C4 能力和功能所需的许多基因。在成熟的 C4 叶中，编码主要 CO2 固定酶 Rubisco 大亚基的质体 rbcL 基因在 BS 细胞内特异性表达。大量研究表明，BS 特异性 rbcL 基因表达主要在转录后水平通过控制翻译和 mRNA 稳定性进行调节。多年来，鉴定与 rbcL 基因表达 C4 模式相关的调控因子一直是一个难以实现的目标。 RLSB 由核 RLSB 基因编码，是一种从 C4 叶绿体中纯化的 S1 结构域 RNA 结合蛋白，基于其在体外与质体编码的 rbcL mRNA 的特异性结合。 RLSB 与 LSU 共定位于叶绿体，在许多植物物种中高度保守。最重要的是，RLSB 特异性定位于 C4 植物中的叶束鞘 (BS) 细胞。使用玉米 (C4) 和拟南芥 (C3) 的比较分析揭示了其与两种植物中 rbcL 基因表达的紧密相关性。 RLSB 表达的减少（分别通过插入突变或 RNA 沉默）导致 rbcL mRNA 积累和 LSU 产量减少。其他发育影响，例如绿叶/黄叶，可能与光合功能下降和相关信号网络破坏有关。由于插入突变或基因沉默，RLSB 表达的减少与玉米和拟南芥中 rbcL 基因表达的减少严格相关。在两种植物中，rbcL mRNA 的积累以及 LSU 蛋白的合成都受到影响。这些发现表明，BS 叶绿体内 RLSB 结合蛋白与 rbcL mRNA 的特异性积累和结合可能是导致 Rubisco 在 C4 植物中特征性细胞类型特异性定位的决定因素。 RLSB 表达的进化修饰，从 C3“默认”状态到 BS 细胞特异性，可能代表了 rbcL 表达仅限于 C4 植物中一种细胞类型的一种机制。
Plants that utilize the highly efficient C4 pathway of photosynthesis typically possess kranz-type leaf anatomy that consists of two morphologically and functionally distinct photosynthetic cell types, the bundle sheath (BS) and mesophyll (M) cells. These two cell types differentially express many genes that are required for C4 capability and function. In mature C4 leaves, the plastidic rbcL gene, encoding the large subunit of the primary CO2 fixation enzyme Rubisco, is expressed specifically within BS cells. Numerous studies have demonstrated that BS-specific rbcL gene expression is regulated predominantly at post-transcriptional levels, through the control of translation and mRNA stability. The identification of regulatory factors associated with C4 patterns of rbcL gene expression has been an elusive goal for many years. RLSB, encoded by the nuclear RLSB gene, is an S1-domain RNA binding protein purified from C4 chloroplasts based on its specific binding to plastid-encoded rbcL mRNA in vitro. Co-localized with LSU to chloroplasts, RLSB is highly conserved across many plant species. Most significantly, RLSB localizes specifically to leaf bundle sheath (BS) cells in C4 plants. Comparative analysis using maize (C4) and Arabidopsis (C3) reveals its tight association with rbcL gene expression in both plants. Reduced RLSB expression (through insertion mutation or RNA silencing, respectively) led to reductions in rbcL mRNA accumulation and LSU production. Additional developmental effects, such as virescent/yellow leaves, were likely associated with decreased photosynthetic function and disruption of associated signaling networks. Reductions in RLSB expression, due to insertion mutation or gene silencing, are strictly correlated with reductions in rbcL gene expression in both maize and Arabidopsis. In both plants, accumulation of rbcL mRNA as well as synthesis of LSU protein were affected. These findings suggest that specific accumulation and binding of the RLSB binding protein to rbcL mRNA within BS chloroplasts may be one determinant leading to the characteristic cell type-specific localization of Rubisco in C4 plants. Evolutionary modification of RLSB expression, from a C3 “default” state to BS cell-specificity, could represent one mechanism by which rbcL expression has become restricted to only one cell type in C4 plants.
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DOI：
10.1007/978-1-60327-563-7_2
发表时间：
2009-01-01
期刊：
PLANT SYSTEMS BIOLOGY
影响因子：
--
作者：
Barkan, Alice
通讯作者：
Barkan, Alice
影响因子：
5.3
作者：
BERRY, JO;NIKOLAU, BJ;KLESSIG, DF
通讯作者：
KLESSIG, DF
影响因子：
6.9
作者：
Hetherington, SE;Smillie, RM;Davies, WJ
通讯作者：
Davies, WJ
影响因子：
7.2
作者：
Acevedo-Hernández, GJ;León, P;Herrera-Estrella, LR
通讯作者：
Herrera-Estrella, LR
DOI：
10.1073/pnas.88.8.3502
发表时间：
1991-04-01
影响因子：
11.1
作者：
BARKAN, A;MARTIENSSEN, RA
通讯作者：
MARTIENSSEN, RA