Survey of conserved alternative splicing events of mRNAs encoding SR proteins in land plants
Survey of conserved alternative splicing events of mRNAs encoding SR proteins in land plants
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DOI：
10.1093/molbev/msj118
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发表时间：
2006-05-01
影响因子：
10.7
通讯作者：
Go, M
中科院分区：
文献类型：
--
作者：
Iida, K;Go, M
富含丝氨酸/精氨酸(SR)蛋白家族在结构性剪接和选择性剪接(AS)中起着重要作用。这些蛋白质以组织特异性和应激反应的方式调节AS。编码SR蛋白的前mRNAs经常被选择性剪接，这些AS事件可能对其他Pre-mRNAs的AS事件的调控很重要。在本研究中，我们分析了拟南芥和水稻SR蛋白的AS事件。我们发现了三组在拟南芥和水稻之间保守的AS事件。这些保守的事件在植物新奇SR蛋白SC35样蛋白(SCL)和两锌指节型9G8亚家族中被发现。这些亚家族的每个成员都有至少一个RNA识别基序(RRM)和至少一个RRM编码区的内含子。我们发现，保守的AS事件发生在这些内含子中，在每种情况下，保守的AS事件导致成熟的mRNAs编码不完整的RRMS蛋白。为了探索这些AS事件的进化起源，我们除了分析拟南芥和水稻中的SR蛋白外，还分析了Physcomitrella patens(MOSS)中的SR蛋白。我们在Silico中发现了植物新奇SR蛋白SCL和两个锌指节型9G8亚家族的苔藓同源基因，这些同源基因在拟南芥和水稻中保守的AS位点的同一位置有很长的内含子。这种长内含子是与拟南芥SR蛋白基因相关的选择性剪接内含子所特有的。在苔藓SR蛋白基因中发现的长内含子强烈表明，苔藓SR蛋白基因中保守的AS事件可能与拟南芥和水稻中的类似。我们将保守AS的进化起源追溯到400年，也就是植物首次入侵陆地的时候。这些事件在整个AS事件的调控中可能是重要的，并可能有助于AS描述的复杂转录组。受调控的AS事件创建的复杂转录组可能为植物提供了对干旱或温度变化的耐受性，并赋予了它们在陆地上生活的能力。
The serine/arginine-rich (SR) protein family plays an important role in constitutive and alternative splicing (AS). These proteins regulate AS in a tissue-specific and stress-responsive manner. Pre-mRNAs encoding SR proteins are often alternatively spliced, and these AS events may be important for the regulation of AS events of other pre-mRNAs. In this study, we analyzed AS events of SR proteins in Arabidopsis thaliana and Oryza sativa (rice). We found three sets of AS events conserved between Arabidopsis and rice. These conserved AS events were found in the plant-novel-SR protein, SC35-like (SCL), and two-Zn-knuckles-type 9G8 subfamilies. Each member of these subfamilies has at least one RNA recognition motif (RRM) and at least one intron in the RRM-encoded region. We found that the conserved AS events occurred in these introns and, in each case, the conserved AS events resulted in mature mRNAs encoding proteins with incomplete RRMs. To search for the evolutionary origin of these AS events, we analyzed SR proteins in Physcomitrella patens (moss) in addition to those in Arabidopsis and rice. We found moss homologues of the plant-novel-SR protein, SCL, and the two-Zn-knuckles-type 9G8 subfamilies in silico, and these homologues have long introns at the same location of the conserved AS sites in Arabidopsis and rice. Such long introns are quite specific for alternatively spliced introns concerning the Arabidopsis SR protein genes. The long introns found in the moss SR protein genes strongly suggested that conserved AS events in moss SR protein genes might be similar to those in Arabidopsis and rice. We traced the evolutionary origin of the conserved AS events to 400 MYA, when plants first invaded land. These events are likely important in the regulation of whole AS events and likely contribute to the complicated transcriptome described by AS. The complicated transcriptome created by regulated AS events might have provided plants tolerance against droughts or temperature shifts and given them the ability to live on land.