Polyubiquitin insertions and the phylogeny of Cercozoa and Rhizaria
Polyubiquitin insertions and the phylogeny of Cercozoa and Rhizaria
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DOI：
10.1016/j.protis.2005.03.001
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发表时间：
2005-08-01
期刊：
影响因子：
2.5
通讯作者：
Cavalier-Smith, T
中科院分区：
文献类型：
--
作者：
Bass, D;Moreira, D;Cavalier-Smith, T
在通用真核蛋白多聚泛素的单体-单体连接处插入一个或两个氨基酸是尾虫纲和有孔虫纲所特有的，它们是原生动物界内根茎中密切相关的“核心”门。我们筛选了 11 种其他候选根虫：Radiozoa（多胱氨酸和棘轮放射虫）、“微日虫”和 Apusozoa；都缺乏它，这支持了有孔虫与尾虫的关系比与其他真核生物更密切的观点。确定了另外 12 只尾虫的插入大小，以帮助解决它们的基本分支顺序。最早的分支尾虫通常有一个氨基酸插入，像所有有孔虫一样，但一个由除 Metopion、Helkesimastix 和 Cercobodo agilis 之外的所有 Monadofilosa 组成的大型衍生进化枝有两个氨基酸，表明一次加倍事件，并且没有回复到单个氨基酸。 Metromonas 和 Sainouron 是位置不确定的尾虫，具有双重插入，表明它们属于 Monadofilosa。与大多数距离树相比，贝叶斯树上 Metopion 和 Cercobodo 的位置较高，这表明不能排除另一种解释，即第二次插入发生在祖先 filosan 中较早，随后在 Chlorarachnea、Metopion 和 Cercobodo 中三个独立地回复为单个氨基酸。 (c) 2005 年爱思唯尔有限公司。版权所有。
A single or double amino acid insertion at the monomer-monomer junction of the universal eukaryotic protein polyubiquitin is unique to Cercozoa and Foraminifera, closely related 'core' phyla in the protozoan infralkingdom Rhizaria. We screened 11 other candidate rhizarians for this insertion: Radiozoa (polycystine and acantharean radiolaria), a 'microheliozoan', and Apusozoa; all lack it, supporting suggestions that Foraminifera are more closely related to Cercozoa than either is to other eukaryotes. The insertion's size was ascertained for 12 additional Cercozoa to help resolve their basal branching order. The earliest branching Cercozoa generally have a single amino acid insertion, like all Foraminifera, but a large derived clade consisting of all Monadofilosa except Metopion, Helkesimastix, and Cercobodo agilis has two amino acids, suggesting one doubling event and no reversions to a single amino acid. Metromonas and Sainouron, cercozoans of uncertain position, have a double insertion, suggesting that they belong in Monadofilosa. An alternative interpretation, suggested by the higher positions for Metopion and Cercobodo on Bayesian trees compared with most distance trees, cannot be ruled out, i.e. that the second insertion took place earlier, in the ancestral filosan, and was followed by three independent reversions to a single amino acid in Chlorarachnea, Metopion and Cercobodo. (c) 2005 Elsevier GmbH. All rights reserved.