Department of Biological Sciences, University of Naples Federico II, Napoli, Italy.
C R Biol. 2012 Jul;335(7):480-7. doi: 10.1016/j.crvi.2012.05.003. Epub 2012 Jun 17.
Metallothioneins are cysteine-rich, low-molecular weight metal-binding proteins ubiquitously expressed in living organisms. In the last past years, the increasing amount of vertebrate non-mammalian metallothionein sequences available have disclosed for these proteins differences in the primary structure that have not been supposed before. To provide a more up-to-date view of the metallothioneins in non-mammalian tetrapods, we decided to increase the still scarce knowledge concerning the primary structure and the evolution of metallothioneins in amphibians. Our data demonstrate an unexpected diversity of metallothionein sequences among amphibians, accompanied by remarkable features in their phylogeny. Phylogenetic analysis also reveals the complexity of vertebrate metallothionein evolution, made by both ancient and more recent events of gene duplication and loss.
金属硫蛋白是富含半胱氨酸、分子量较小的金属结合蛋白，在所有生物体中广泛表达。在过去的几年中，越来越多的脊椎动物非哺乳动物金属硫蛋白序列的出现揭示了这些蛋白质在一级结构上的差异，而这些差异以前是未曾预料到的。为了更全面地了解非哺乳动物四足动物中的金属硫蛋白，我们决定增加有关两栖动物中金属硫蛋白一级结构和进化的仍然稀缺的知识。我们的数据表明，两栖动物中的金属硫蛋白序列存在令人意外的多样性，并且在其系统发育中存在显著特征。系统发育分析还揭示了脊椎动物金属硫蛋白进化的复杂性，这是由古老和更近的基因复制和丢失事件共同造成的。
