Identification and characterization of the telomerase reverse transcriptase of Bombyx mori (silkworm) and Tribolium castaneum (flour beetle)
Identification and characterization of the telomerase reverse transcriptase of Bombyx mori (silkworm) and Tribolium castaneum (flour beetle)
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DOI：
10.1016/j.gene.2006.04.022
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发表时间：
2006-07-19
期刊：
影响因子：
3.5
通讯作者：
Fujiwara, Haruhiko
中科院分区：
文献类型：
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作者：
Osanai, Mizuko;Kojima, Kenji K.;Fujiwara, Haruhiko
大多数真核生物的染色体末端由简单的端粒重复序列组成。节肢动物的端粒一般由TTAGG五核苷酸重复序列组成；然而，包括果蝇在内的一些昆虫物种没有端粒重复序列。相比之下，家蚕含有TTAGG型端粒重复序列，但并未在所研究的所有组织中检测到端粒酶活性。为了寻找昆虫端粒结构异常的原因，我们从家蚕和粉甲中鉴定了端粒酶逆转录酶(TERT)亚单位。这是首次报道节肢动物的端粒酶基因。家蚕TERT基因(BnzoTERT)和面粉甲虫TERT基因(TCasTERT)都没有N-末端GQ基序，与BmoTERT基因组DNA的比较表明，BmoTERT没有内含子。BmoTERT在其5‘非编码区含有5个ATG密码子，这可能会减少ElmoTERT蛋白的翻译。Northern杂交表明，BmoTERT的转录水平很低。BmoTERT的这些独特功能可能解释了无法检测到的家蚕端粒酶活性。(C)2006爱思唯尔B.V.保留所有权利。
Chromosomal ends of most eukaryotes are composed of simple telomeric repeats. Arthropod telomeres are generally constituted by TTAGG pentanucleotide repeats; however, some insect species including Drosophila melanogaster do not have telomeric repeats. In contrast, the domestic silkworm Bombyx mori contains TTAGG-type telomeric repeats, but the telomerase activity has not been detected in all investigated tissues. To search for a cause of unusual telomere structure in insects, we here identified telomerase reverse transcriptase (TERT) subunit from the domestic silkworm B. mori and the flour beetle Tribolium castaneum. This is the first report of telomerase genes from arthropods. The domestic silkworm TERT gene (BnzoTERT) and the flour beetle TERT gene (TcasTERT) both did not have the N-terminal GQ motif Comparison between cDNA and genomic DNA of BmoTERT revealed that it includes no introns. BmoTERT contains five ATG codons in its 5'UTR, which could reduce the translation of ElmoTERT proteins. Also, Northern hybridization indicated that BmoTERT is transcribed at a very low level. These unique features of BmoTERT possibly explain the undetectable Bombyx telomerase activity. (c) 2006 Elsevier B.V. All rights reserved.