In recent years, transcriptomic databases have become one of the main sources for protein discovery. In our studies of nervous system and digestive tract regeneration in echinoderms, we have identified several transcripts that have attracted our attention. One of these molecules corresponds to a previously unidentified transcript ( Orpin ) from the sea cucumber Holothuria glaberrima that appeared to be upregulated during intestinal regeneration. We have now identified a second highly similar sequence and analyzed the predicted proteins using bioinformatics tools. Both sequences have EF-hand motifs characteristic of calcium-binding proteins (CaBPs) and N-terminal signal peptides. Sequence comparison analyses such as multiple sequence alignments and phylogenetic analyses only showed significant similarity to sequences from other echinoderms or from hemichordates. Semi-quantitative RT-PCR analyses revealed that transcripts from these sequences are expressed in various tissues including muscle, haemal system, gonads, and mesentery. However, contrary to previous reports, there was no significant differential expression in regenerating tissues. Nonetheless, the identification of unique features in the predicted proteins suggests that these might comprise a novel subfamily of EF-hand containing proteins specific to the Ambulacraria clade.

中文翻译：

---

两种新型EF手蛋白的特征鉴定了特定于Ambulacraria的假定的Ca2 +结合蛋白进化枝

近年来，转录组数据库已成为蛋白质发现的主要来源之一。在我们对棘皮动物神经系统和消化道再生的研究中，我们发现了一些成绩单，这些成绩单引起了我们的注意。这些分子之一对应于来自海参Holothuria glaberrima的先前未鉴定的转录本（Orpin），在肠道再生过程中似乎被上调了。现在，我们确定了第二个高度相似的序列，并使用生物信息学工具分析了预测的蛋白质。这两个序列都具有钙结合蛋白（CaBPs）和N端信号肽特征的EF手基序。诸如多个序列比对和系统发育分析之类的序列比较分析仅显示出与来自其他棘皮动物或来自半hor酸盐的序列的显着相似性。半定量RT-PCR分析显示，这些序列的转录本在各种组织中表达，包括肌肉，血液系统，性腺和肠系膜。但是，与以前的报道相反，再生组织中没有明显的差异表达。尽管如此，对预测蛋白质独特特征的鉴定表明，这些蛋白质可能包含一个新的EF手亚家族，其中包含特有的Ambulacraria进化枝蛋白质。与以前的报道相反，再生组织中没有明显的差异表达。尽管如此，对预测蛋白质独特特征的鉴定表明，这些蛋白质可能包含一个新的EF手亚家族，其中包含特有的Ambulacraria进化枝蛋白质。与以前的报道相反，再生组织中没有明显的差异表达。尽管如此，对预测蛋白质独特特征的鉴定表明，这些蛋白质可能包含一个新的EF手亚家族，其中包含特有的Ambulacraria进化枝蛋白质。