Key Laboratory of Resource Biology and Eco-environment of Ministry of Education, Sichuan Key Laboratory of Molecular Biology and Biotechnology, College of Life Science, Sichuan University, Chengdu, 610064, People's Republic of China.
Mol Biol Rep. 2013 Nov;40(11):6309-21. doi: 10.1007/s11033-013-2744-7. Epub 2013 Sep 25.
Two-dimensional electrophoresis, coupled with MALDI-TOF-MS, was used to identify differentially expressed proteins between young and mature leaves of sweet potato [Ipomoea batatas (L.) Lam]. The results showed that there were 25 differential proteins between young and mature leaves. The Rubisco activase (RCA) that catalyzes the activation of Rubisco in vivo and plays a crucial role in photosynthesis was among these 25 proteins. So far, little was known about the molecular biology of RCA in sweet potato. Here, this research reports the cloning and characterization of two genes encoding the short isoform and the long isoform of sweet potato RCAs. Analysis of DNA sequences of RCA suggested that the corresponding mRNAs were transcribed from two different genes. To study the roles of these two RCA isoforms in photosynthesis, we investigated the expression patterns of these RCA genes at the mRNA and protein levels every 2 h in a photoperiod and under different temperatures conditions. The results indicated that these two RCA isoforms may play different roles in regulating photosynthesis and they may be regulated by light, heat or both. In addition, there were interactions between Rubisco large subunit (RBCl) and short isoform RCA (RCAs) as well as RCAs and long isoform RCA (RCAl), but no interaction between RBCl and RCAl, implying they might form a sandwich-like structure (RBCl-RCAs-RCAl), at least in yeast cells. These results provided new information on the modulation of RCA genes in sweet potato, which could be useful in improving photosynthesis and plant growth in sweet potato.
双向电泳结合 MALDI-TOF-MS 用于鉴定甘薯[Ipomoea batatas（L.）Lam]幼叶和成熟叶之间差异表达的蛋白质。结果表明，幼叶和成熟叶之间有 25 种差异蛋白。Rubisco 激活酶（RCA）是体内催化 Rubisco 激活并在光合作用中起关键作用的一种蛋白质。到目前为止，人们对甘薯 RCA 的分子生物学知之甚少。本研究报告了两个编码甘薯 RCA 短同工型和长同工型的基因的克隆和特性。对 RCA 的 DNA 序列分析表明，相应的 mRNA 是由两个不同的基因转录而来的。为了研究这两种 RCA 同工型在光合作用中的作用，我们在光周期和不同温度条件下，每隔 2 小时研究这些 RCA 基因在 mRNA 和蛋白质水平上的表达模式。结果表明，这两种 RCA 同工型可能在调节光合作用中发挥不同的作用，它们可能受到光、热或两者的调节。此外，Rubisco 大亚基（RBCl）与短同工型 RCA（RCAs）以及 RCAs 与长同工型 RCA（RCAl）之间存在相互作用，但 RBCl 与 RCAl 之间没有相互作用，这表明它们可能形成三明治样结构（RBCl-RCAs-RCAl），至少在酵母细胞中是这样。这些结果为甘薯中 RCA 基因的调节提供了新的信息，这可能有助于提高甘薯的光合作用和植物生长。
