Identification and characterization of sea squirt telomerase reverse transcriptase
Identification and characterization of sea squirt telomerase reverse transcriptase
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DOI：
10.1016/j.gene.2007.05.013
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发表时间：
2007-10-01
期刊：
影响因子：
3.5
通讯作者：
Chen, Julian J. -L.
中科院分区：
文献类型：
--
作者：
Li, Yang;Yates, Joel A.;Chen, Julian J. -L.
在大多数真核生物中，端粒酶是维持端粒长度和染色体稳定性所必需的。端粒酶核糖核蛋白复合物由两种基本组分组成，催化端粒酶逆转录酶蛋白（TERT）和内源性端粒酶RNA。海虾夷类作为尾索动物在脊索动物系统发育树中占有重要地位，它们在脊椎动物谱系之前与其他脊索动物分化，从而为脊椎动物基因的起源和进化提供了特殊的见解。在这里，我们报告的两个海鞘，玻璃海鞘和玻璃海鞘的端粒酶逆转录酶基因的克隆和特性。梭大肠杆菌TERT（CinTERT）基因编码907个氨基酸，由17个外显子组成，与脊椎动物的TERT基因相似。梭Savignyi TERT（CsaTERT）基因编码843个氨基酸，但令人惊讶地不含任何内含子。两种玻璃海鞘TERT均含有端粒酶和病毒RT中通常存在的所有逆转录酶（RT）基序（1、2、A、B、C、D和E）。有趣的是，玻璃海鞘和脊椎动物TERT序列的比对揭示了一个以前未知的基序，命名为基序3，位于基序2和A之间。玻璃海鞘TERT基因在除脑和心脏外的所有分析组织中表达。这是第一次在无脊椎脊索动物中发现TERT基因。(c)2007 Elsevier B.V.保留所有权利。
Telomerase is essential for maintaining telomere length and chromosome stability in most eukaryotic organisms. The telomerase ribonucleoprotein complex consists of two essential components, the catalytic telomerase reverse transcriptase protein (TERT) and the intrinsic telomerase RNA. The sea squirts, as urochordates, occupy a key position in the phylogenetic tree of the chordates: they diverged from the other chordates just before the lineage of vertebrates, and thus provide special insight into the origin and evolution of vertebrate genes. Here, we report the cloning and characterization of TERT genes from two sea squirts, Ciona intestinalis and Ciona savignyi. The C. intestinalis TERT (CinTERT) gene encodes 907 amino acids and consists of 17 exons, which are similar to vertebrate TERT genes. The C. savignyi TERT (CsaTERT) gene encodes 843 amino acids, but surprisingly does not contain any introns. Both Ciona TERTs contain all of the reverse transcriptase (RT) motifs (1, 2, A, B, C, D, and E) that are typically present in telomerase and viral RTs. Interestingly, the alignment of Ciona and vertebrate TERT sequences reveals a previously unknown motif, named motif 3, located between motifs 2 and A. The Ciona TERT gene is expressed in all tissues analyzed except the brain and heart. This is the first report of the TERT gene in invertebrate chordates. (c) 2007 Elsevier B.V. All rights reserved.