An Chuanjing, Gao Yuefang, Li Jinyu, Liu Xiaomin, Gao Fuli, Gao Hongbo
College of Biological Sciences and Technology, Beijing Forestry University, Beijing, 100083, China.
Plant Cell Rep. 2017 Jul;36(7):1027-1036. doi: 10.1007/s00299-017-2131-2. Epub 2017 Mar 28.
A systematic analysis of the Arabidopsis genome in combination with localization experiments indicates that alternative splicing affects the peroxisomal targeting sequence of at least 71 genes in Arabidopsis. Peroxisomes are ubiquitous eukaryotic cellular organelles that play a key role in diverse metabolic functions. All peroxisome proteins are encoded by nuclear genes and target to peroxisomes mainly through two types of targeting signals: peroxisomal targeting signal type 1 (PTS1) and PTS2. Alternative splicing (AS) is a process occurring in all eukaryotes by which a single pre-mRNA can generate multiple mRNA variants, often encoding proteins with functional differences. However, the effects of AS on the PTS1 or PTS2 and the targeting of the protein were rarely studied, especially in plants. Here, we systematically analyzed the genome of Arabidopsis, and found that the C-terminal targeting sequence PTS1 of 66 genes and the N-terminal targeting sequence PTS2 of 5 genes are affected by AS. Experimental determination of the targeting of selected protein isoforms further demonstrated that AS at both the 5' and 3' region of a gene can affect the inclusion of PTS2 and PTS1, respectively. This work underscores the importance of AS on the global regulation of peroxisome protein targeting.
对拟南芥基因组进行的系统分析结合定位实验表明，可变剪接影响拟南芥中至少71个基因的过氧化物酶体靶向序列。过氧化物酶体是普遍存在的真核细胞器，在多种代谢功能中起关键作用。所有过氧化物酶体蛋白均由核基因编码，并主要通过两种靶向信号靶向过氧化物酶体：1型过氧化物酶体靶向信号（PTS1）和PTS2。可变剪接（AS）是所有真核生物中都会发生的一个过程，通过该过程，单个前体mRNA可以产生多个mRNA变体，这些变体通常编码具有功能差异的蛋白质。然而，AS对PTS1或PTS2以及蛋白质靶向的影响很少被研究，尤其是在植物中。在这里，我们对拟南芥基因组进行了系统分析，发现66个基因的C端靶向序列PTS1和5个基因的N端靶向序列PTS2受AS影响。对选定蛋白质异构体靶向的实验测定进一步证明，基因5'和3'区域的AS分别可以影响PTS2和PTS1的包含。这项工作强调了AS在过氧化物酶体蛋白靶向的全局调控中的重要性。
