番茄 calnexin 基因的克隆及胁迫表达分析

Calnexin是内质网中重要的类凝集素分子伴侣,其主要作用是辅助糖基化蛋白的折叠和装配,调节内质网中的Ca2 稳态平衡和Ca2 信号传导过程。从番茄(Lycopersicon esculentum)的cDNA文库中克隆到calnexincDNA全序列,将其命名为Lecnx61.0,并以其3’端DNA片段为探针对番茄基因组进行Southern分析,结果表明Lecnx61.0在该基因组中仅有一个拷贝;Northern和W estern分析表明,Lecnx61.0的表达还受热激、冷害、盐害和内质网应激诱导剂衣霉素的诱导,但对干旱胁迫没有明显的反应。LeCNX 61.0蛋白对Ca2 亏缺胁迫的响应呈现组织特异性,但高浓度Ca2 并不影响各组织中LeCNX 61.0蛋白的含量,实验结果表明LeCNX 61.0蛋白可能在植物抵抗特定的环境胁迫中发挥作用。

Cloning and Stress Expression Analysis of Calnexin in Tomato

Calnexin,an important lectin-like chaperone in endoplasm reticulum,can assist in protein fol-(ding) and modulate Ca~(2 ) homeostasis in cell.A cDNA of 1964 bp encoding a full-length calnexin was cloned from Lycopersicon esculentum,and designated as(Lecnx61.0).A single copy of(Lecnx61.0) was found in tomato genomic DNA by Southern-blot analysis.The levels of mRNA and protein of(Lecnx61.0) were increased when plants were treated by heat shock,chilling shock,salinity stress and endoplasm reticulum stress,but(Lecnx61.0) had no obvious response to drought stress.The protein of(LeCNX61.0) only in speci-(fic) tissues made response to Ca~(2 ) depletion.Howerver,the expression of(LeCNX61.0) was not induced by high concentration of Ca~(2 ).These results suggested that(LeCNX61.0) might play an important role in stress tolerance.