摘要
LIM结构域蛋白是一个重要的发育调控因子 ,参与基因转录、细胞骨架建成和信号传导等许多发育调控过程。胞质骨架是形成和稳定细胞形态以及传递物质、能量和信息的重要成分。为研究棉花纤维细胞发育过程中胞质骨架的形成和作用机理 ,通过棉花纤维EST序列整合 ,从陆地棉徐州 14 2胚珠 (含纤维 )中扩增并克隆出棉花LIM结构域基因的编码区段。该棉花LIM结构域基因 (GhLIM1)长 84 8bp ,包含一个 5 70bp的开放阅读框 ,推导的氨基酸序列 (189个氨基酸 )与拟南芥、烟草和向日葵的LIM结构域蛋白有极高的同源性 ,而且两个LIM结构域完整。每个LIM结构域具有植物LIM结构域共有的双锌指结构C X2 C X17～ 19 H X2 C X2 C X2 C X16～ 2 4 C X2 H。RT PCR和Northern杂交分析表明 ,该基因 (GhLIM1)在陆地棉的根、茎尖、下胚轴、叶片、花蕾、花药、胚珠和不同发育时期的陆地棉纤维 (4DPA、12DPA、18DPA)以及海岛棉纤维 (18DPA)和中棉纤维 (12DPA)中均有表达 ,但GhLIM1基因在茎尖、纤维和有纤维的胚珠中表达量更高 ,因此GhLIM1基因应与棉花纤维发育有密切关系。
LIM domain protein plays an important role in various cellular processes,including construction of cytoskeleton,transcription control and signal transduction.Based on cotton fiber EST database and contig analysis,the coding region of a cotton LIM domain protein gene ( GhLIM1 ) was obtained by RT PCR from 4DPA (day post anthesis) ovule with fiber.The cloned fragment of 848 bp contains an open reading frame of 570 bp,coding for a polypeptide of 189 amino acids.It was demonstrated that the deduced GhLIM1 protein was highly homologous to the LIM domain protein of sunflower ( Helianthus annuus ),tobacco ( Nicotiana tabacum ) and Arabidopsis thaliana .Two intact LIM domains,with the conserved sequence of a double zinc finger structure (C X2 C X17～19 H X2 C X2 C X2 C X16～24 C X2 H),were found in the GhLIM1 protein.RT PCR and Northern blot analysis showed that GhLIM1 gene expressed in root,shoot tip,hypocotyls,bud,leaf,anther,ovule and fiber (4DPA,12DPA,18DPA).However it was preferentially expressed in the shoot tip,fiber and ovule.It was proposed that the express of GhLIM1 gene is related to cotton fiber development.
基金
国家自然科学基金资助项目 (批准号 :3 983 0 2 40
3 0 170 5 88和 3 9870 5 3 2 )
国家教委博士点基金 (批准号 :1999 0 0 60 0 3 )
国家转基因植物研究与产业化专项课题 (ZJY A 0 1)~~
