摘要
水通道蛋白是一类较小的跨膜蛋白质,在植物抵御非生物胁迫过程中具有非常重要的作用。为了研究砂藓水通道蛋白基因的生物学功能,利用干旱处理转录组测序获得的序列信息,克隆获得1个水通道蛋白家族中质膜内在蛋白基因序列,命名为RcPIP2。生物信息学结果显示,RcPIP2基因全长序列为1 267 bp,包含807 bp的开放阅读框,编码含有268个氨基酸残基的蛋白质。该蛋白质分子质量预测为28.3 ku,理论等电点为6.64,为疏水性较强的稳定性蛋白;无信号肽,为非分泌型蛋白;含有6个跨膜结构域。保守结构域分析发现,RcPIP2具有膜内在蛋白(MIP)家族信号序列、高等植物高度保守序列HINPAVTFG和2个天门冬酰胺-脯氨酸-丙氨酸(NPA)基序。二级结构包括α螺旋(37.31%)、β折叠(20.9%)、无规则卷曲(38.43%)。三级结构预测发现,RcPIP2蛋白质的立体结构为典型的四聚体形式,由4个圆筒状亚基和中间的孔道构成。系统进化树分析表明,RcPIP2与小立碗藓中的PIP2蛋白质亲缘关系较近,聚为一类。由此推测,RcPIP2基因为水通道蛋白家族成员。
Aquaporins(AQPs)are small transmembrane proteins,and play an important role in tolerance of plants to abiotic stresses.To study the biological functions of aquaporin genes from Racomitrium canescens,a novel plasma membrane intrinsic protein gene of aquaporin family designated RcPIP2 was isolated from the drought transcriptome sequences.The bioinformation results showed that the cDNA full length of RcPIP2 gene was 1 267 bp,which contained an open reading frame of 807 bp and encoded a protein of 268 amino acid residues.It was predicted that the molecular weight of the protein was 28.3 ku,and its theoretical isoelectric point was 6.64,belonging to a stable and hydrophobic protein with no signal peptide.It was a non-secretory protein.RcPIP2 exhibited a typical structure with six transmembrane domains,and had the highly conserved sequence HINPAVTFG of membrane intrinsic protein(MIP)family and two highly conserved Asn-Pro-Ala(NPA)peptides.Its secondary structure contained 37.31%α-helixes,20.9%β-sheets,and 38.43%random curls.The three-dimensional structure of the RcPIP2 protein was a typical tetramer consisting of four cylindrical subunits and the middle channel.Phylogenetic tree analysis indicated that the protein had the closest genetic relationship with PIP2 protein of Physcomitrella patens,being grouped to the same class.It was inferred that RcPIP2 was one of the aquapion family members.
作者
张梅娟
徐红红
马天意
钱朋智
沙伟
ZHANG Meijuan;XU Honghong;MA Tianyi;QIAN Pengzhi;SHA Wei(College of Life Sciences,Agriculture and Forestry,Heilongjiang Provincial Key Laboratory of Resistance Gene Engineering and Protection of Biodiversity in Cold Areas,Qiqihar University,Qiqihar161006,China;College of Food and Bioengineering,Qiqihar University,Qiqihar161006,China)
出处
《华北农学报》
CSCD
北大核心
2019年第5期30-36,共7页
Acta Agriculturae Boreali-Sinica
基金
国家自然科学基金项目(31570207)
黑龙江省省属高等学校基本科研业务费科研项目(135209262
USTSXK201834)
黑龙江省自然科学基金重点项目(ZD201408)
