Four transthyretin-like genes of the migratory plant-parasitic nematode Radopholus similis:: Members of an extensive nematode-specific family
Four transthyretin-like genes of the migratory plant-parasitic nematode Radopholus similis:: Members of an extensive nematode-specific family
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DOI：
10.1016/j.gene.2007.07.015
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发表时间：
2007-11-01
期刊：
影响因子：
3.5
通讯作者：
Gheysen, Godelieve
中科院分区：
文献类型：
--
作者：
Jacob, Joachim;Vanholme, Bartel;Gheysen, Godelieve
从植物寄生线虫Radopholus similis中筛选1154个EST，得到7个编码具有transthyretinlike结构域（PF 01060）的蛋白质的标签。这7个EST对应于从cDNA文库中克隆的4个不同基因（登录号AM 691117、AM 691118、AM 691119、AM 691120）。甲状腺素运载蛋白样基因属于一个大家族，不同于甲状腺素运载蛋白和甲状腺素运载蛋白相关基因，它们在蛋白质水平上具有一定的序列相似性。这种相似性导致了过去不同名称和缩写的不一致使用。为了避免进一步的混淆，我们为这个基因家族引入了一个标准化的命名法，并选择将这个几乎没有特征的基因家族命名为ttl（就像甲状腺素运载蛋白样）。对这些被命名为Rs-ttl-1至Rs-ttl-4的基因的进一步研究表明，它们在青少年和成年人中都有表达，但在年轻的胚胎中没有表达。全坐骑原位杂交揭示了一个独特的空间表达模式的两个基因：RS-TTL-1的外阴周围的组织中表达，而RS-TTL-2的腹神经索中表达。推导的蛋白质序列含有一个推定的分泌信号肽，指向成熟蛋白质的胞外功能。数据库筛选显示ttl家族仅限于线虫。此外，HMMER搜索显示，来自ttl基因的EST在寄生线虫文库中更丰富，偏向于寄生阶段。尽管他们丰富的线虫，包括广泛研究的模式生物秀丽隐杆线虫，TTL蛋白的功能仍然不清楚。我们的数据表明它在神经系统中起作用。即使没有深入了解其生物学功能，该基因家族的线虫特异性性质也使其成为杀线虫剂或RNAi介导的防治寄生线虫策略的有希望的靶标。(C)2007 Elsevier B. V.保留所有权利。
Screening 1154 ESTs from the plant-parasitic nematode Radopholus similis resulted in seven tags coding for proteins holding a transthyretinlike domain (PF01060). The seven ESTs corresponded to four different genes which were cloned from a cDNA library (accession numbers AM691117, AM691118, AM691119, AM691120). Transthyretin-like genes belong to a large family, different from the transthyretin and the transthyretin-related genes with whom they share some sequence similarity at the protein level. This similarity has caused an inconsistent use of different names and abbreviations in the past. To avoid further confusion, we introduce a standardized nomenclature for this gene family, and chose to name this barely characterized gene family ttl (as for transthyretin-like). Further examination of the identified genes, named Rs-ttl-1 to -4, showed that they are expressed in both juveniles and adults, but not in young embryos. Whole mount in situ hybridization revealed a distinct spatial expression pattern for two of the genes: Rs-ttl-1 is expressed in the tissues surrounding the vulva, whereas Rs-ttl-2 is expressed in the ventral nerve cord. The deduced protein sequences contain a putative signal peptide for secretion, pointing to an extracellular function of the mature proteins. Database screens showed that the ttl family is restricted to nematodes. Moreover, a HMMER search revealed that ESTs derived from ttl genes are more abundant in parasitic nematode libraries, with a bias towards the parasitic stages. Despite their abundance in nematodes, including the extensively studied model organism Caenorhabditis elegans, the function of TTL proteins remains obscure. Our data suggest a role in the nervous system. Even without insight into their biological function, the nematode-specific nature of this gene family makes it a promising target for nematicides or RNAi mediated control strategies against parasitic nematodes. (C) 2007 Elsevier B.V. All rights reserved.