Identification and characterization of a gene encoding a putative lysophosphatidyl acyltransferase from Arachis hypogaea
Identification and characterization of a gene encoding a putative lysophosphatidyl acyltransferase from Arachis hypogaea
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编码花生中假定的溶血磷脂酰基转移酶的基因的鉴定和表征
DOI：
10.1007/s12038-012-9277-4
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发表时间：
2012-12-01
影响因子：
2.9
通讯作者：
Liao, Bo-Shou
中科院分区：
文献类型：
--
作者：
Chen, Si-Long;Huang, Jia-Quan;Liao, Bo-Shou
溶血磷脂酰基转移酶（LPAT）是负责溶血磷脂酸（LPA）酰化的重要酶，在植物中可生成磷脂酸（PA）。其编码基因是油料作物通过基因工程改善油脂成分和提高种子含油量的关键候选基因。本研究通过cDNA文库筛选和cDNA末端快速扩增（RACE）技术分离出一个全长的AhLPAT4基因；我们的数据表明，AhLPAT4有1631个核苷酸，编码一个推测分子量为43.8 kDa、含383个氨基酸残基的蛋白质。推导的蛋白质包含一个保守的酰基转移酶结构域和四个基序（I - IV），具有推测的LPA和酰基辅酶A催化及结合位点。生物信息学分析显示，AhLPAT4包含四个跨膜结构域（TMDs），定位于内质网（ER）膜；详细分析表明，AhLPAT4中的基序I和基序II - III被第三个TMD隔开，分别位于细胞质侧和内质网腔侧，并且AhLPAT4蛋白质表面的疏水残基折叠形成一个疏水通道以容纳酰基链。亚细胞定位分析证实AhLPAT4是一种细胞质蛋白。系统发育分析表明，AhLPAT4与来自大豆、拟南芥和蓖麻的推测的LPAT4蛋白质具有高度同源性（63.7 - 78.3%）。AhLPAT4在除花以外的多种组织中普遍表达，在花中几乎检测不到。花生种子不同发育阶段的表达分析表明，AhLPAT4与油脂积累不一致。[陈S - L，黄J - Q，雷Y，张Y - T，任X - P，陈Y - N，江H - F，严L - Y，李Y - R和廖B - S 2012花生中一个编码推测的溶血磷脂酰基转移酶基因的鉴定与特性分析。《生物科学杂志》37卷1029 - 1039页] DOI 10.1007/s12038 - 012 - 9277 - 4
Lysophosphatidyl acyltransferase (LPAT) is the important enzyme responsible for the acylation of lysophosphatidic acid (LPA), leading to the generation of phosphatidic acid (PA) in plant. Its encoding gene is an essential candidate for oil crops to improve oil composition and increase seed oil content through genetic engineering. In this study, a full-length AhLPAT4 gene was isolated via cDNA library screening and rapid amplification of cDNA ends (RACE); our data demonstrated that AhLPAT4 had 1631 nucleotides, encoding a putative 43.8 kDa protein with 383 amino acid residues. The deduced protein included a conserved acyltransferase domain and four motifs (I–IV) with putative LPA and acyl-CoA catalytic and binding sites. Bioinformatic analysis indicated that AhLPAT4 contained four transmembrane domains (TMDs), localized to the endoplasmic reticulum (ER) membrane; detailed analysis indicated that motif I and motifs II–III in AhLPAT4 were separated by the third TMD, which located on cytosolic and ER luminal side respectively, and hydrophobic residues on the surface of AhLPAT4 protein fold to form a hydrophobic tunnel to accommodate the acyl chain. Subcellular localization analysis confirmed that AhLPAT4 was a cytoplasm protein. Phylogenetic analysis revealed that AhLPAT4 had a high homology (63.7–78.3%) with putative LPAT4 proteins from Glycine max, Arabidopsis thaliana and Ricinus communis. AhLPAT4 was ubiquitously expressed in diverse tissues except in flower, which is almost undetectable. The expression analysis in different developmental stages in peanut seeds indicated that AhLPAT4 did not coincide with oil accumulation.