Aquaporins constitute a large and highly divergent protein family in maize
Aquaporins constitute a large and highly divergent protein family in maize
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DOI：
10.1104/pp.125.3.1206
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发表时间：
2001-03-01
期刊：
影响因子：
7.4
通讯作者：
Jung, R
中科院分区：
文献类型：
--
作者：
Chaumont, F;Barrieu, F;Jung, R
水通道蛋白（Aquaporins，AQP）是一个古老的跨膜转运蛋白家族，广泛存在于真核生物和大多数原核生物中。玉米水通道蛋白的31个全长cDNA的氨基酸序列的比较和系统发育分析表明，它们包括四个不同的高度分化的蛋白质组。我们将其分为质膜固有蛋白（PIP）、液泡膜固有蛋白、Nod 26样固有蛋白和小的碱性固有蛋白。氨基酸序列同一性从16%到100%不等，但所有序列都具有稳定形成水孔的两个环所必需的结构基序和保守氨基酸。最不同的是小的和基本的整合蛋白，其中孔的两个高度保守的Asn-Pro-Ala基序中的第一个不保守，而是由丙氨酸-脯氨酸-苏氨酸或丙氨酸-脯氨酸-丝氨酸表示。我们提出了一个基于哺乳动物AQP 1三维结构的ZmPIP 1 -2模型。AQP序列在包含约470，000个玉米cDNA的数据库集合中被发现的次数的列表表明，少数玉米AQP是非常高表达的，而许多不是大量表达的。系统发育分析支持这样的解释，PIP通过基因重复的分歧发生在最近比其他三个亚家族的成员的分歧。本研究为分析非洲爪蟾卵母细胞中蛋白质的功能，确定基因的组织特异性表达，恢复插入突变体，以及确定在植物中的功能开辟了道路。
Aquaporins (AQPs) are an ancient family of channel proteins that transport water and neutral solutes through a Fore and are found in all eukaryotes and most prokaryotes. A comparison of the amino acid sequences and phylogenetic analysis of 31 full-length cDNAs of maize (Zen mays) AQPs shows that they comprise four different groups of highly divergent proteins. We have classified them as plasma membrane intinsic proteins (PIPs), tonoplast intrinsic proteins, Nod26-like intrinsic proteins, and small and basic intrinsic proteins. Amino acid sequence identities vary from 16% to 100%, but all sequences share structural motifs and conserved amino acids necessary to stabilize the two loops that form the aqueous pore. Most divergent are the mall and basic integral proteins in which the first of the two highly conserved Asn-Pro-Ala motifs of the pore is not conserved, but is represented by alanine-proline-threonine or alanine-proline-serine. We present a model of ZmPIP1-2 based on the three-dimensional structure of mammalian AQP1. Tabulation of the number of times that the AQP sequences are found in a collection of databases that comprises about 470,000 maize cDNAs indicates that a few of the maize AQPs are very highly expressed and many are not abundantly expressed. The phylogenetic analysis supports the interpretation that the divergence of PIPs through gene duplication occurred more recently than the divergence of the members of the ether three subfamilies. This study opens the way to analyze the function of the proteins in Xenopus laevis oocytes, determine the tissue specific expression of the genes, recover insertion mutants, and determine the in planta function.