Park Sang-Je, Huh Jae-Won, Kim Young-Hyun, Kim Heui-Soo, Chang Kyu-Tae
National Primate Research Center, Korea Research Institute of Bioscience and Biotechnology, Ochang, Chungbuk 363-883, Republic of Korea.
Comp Funct Genomics. 2012;2012:170208. doi: 10.1155/2012/170208. Epub 2012 Jun 17.
The Zinc finger, RAN-binding domain-containing protein 2 (ZRANB2), contains arginine/serine-rich (RS) domains that mediate its function in the regulation of alternative splicing. The ZRANB2 gene contains 2 LINE elements (L3b, Plat_L3) between the 9th and 10th exons. We identified the exonization event of a LINE element (Plat_L3). Using genomic PCR, RT-PCR amplification, and sequencing of primate DNA and RNA samples, we analyzed the evolutionary features of ZRANB2 transcripts. The results indicated that 2 of the LINE elements were integrated in human and all of the tested primate samples (hominoids: 3 species; Old World monkey: 8 species; New World monkey: 6 species; prosimian: 1 species). Human, rhesus monkey, crab-eating monkey, African-green monkey, and marmoset harbor the exon derived from LINE element (Plat_L3). RT-PCR amplification revealed the long transcripts and their differential expression patterns. Intriguingly, these long transcripts were abundantly expressed in Old World monkey lineages (rhesus, crab-eating, and African-green monkeys) and were expressed via intron retention (IR). Thus, the ZRANB2 gene produces 3 transcript variants in which the Cterminus varies by transposable elements (TEs) exonization and IR mechanisms. Therefore, ZRANB2 is valuable for investigating the evolutionary mechanisms of TE exonization and IR during primate evolution.
锌指RAN结合结构域蛋白2（ZRANB2）含有富含精氨酸/丝氨酸（RS）的结构域，这些结构域介导其在可变剪接调控中的功能。ZRANB2基因在第9和第10外显子之间包含2个长散在核元件（L3b、Plat_L3）。我们鉴定了一个长散在核元件（Plat_L3）的外显子化事件。通过对灵长类动物DNA和RNA样本进行基因组PCR、RT-PCR扩增及测序，我们分析了ZRANB2转录本的进化特征。结果表明，2个长散在核元件整合在人类及所有测试的灵长类动物样本中（类人猿：3种；旧世界猴：8种；新世界猴：6种；原猴亚目：1种）。人类、恒河猴、食蟹猴、非洲绿猴和狨猴含有源自长散在核元件（Plat_L3）的外显子。RT-PCR扩增揭示了长转录本及其差异表达模式。有趣的是，这些长转录本在旧世界猴谱系（恒河猴、食蟹猴和非洲绿猴）中大量表达，并通过内含子保留（IR）方式表达。因此，ZRANB2基因产生3种转录变体，其C末端因转座元件（TEs）外显子化和IR机制而有所不同。所以，ZRANB2对于研究灵长类动物进化过程中转座元件外显子化和内含子保留的进化机制具有重要价值。
