Characterization of CAX-like genes in plants:: implications for functional diversity
Characterization of CAX-like genes in plants:: implications for functional diversity
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DOI：
10.1016/s0378-1119(00)00390-5
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发表时间：
2000-10-31
期刊：
影响因子：
3.5
通讯作者：
Hirschi, K
中科院分区：
文献类型：
--
作者：
Shigaki, T;Hirschi, K
转运蛋白介导的Ca ~（2+）外排是植物信号转导的重要组成部分。为了阐明Ca 2 +/H+在植物胞质Ca 2+浓度调控中的多样性和作用，从玉米和拟南芥cDNA文库中克隆了Ca 2+交换基因CAX的同源基因。助理拟南芥CAX同源物AtHCX 1与CAX 1的同源性为77%，而Z.玉米CAX的同源物ZmHCX 1与CAX 1的氨基酸序列有64%的同源性。AtHCX 1转录本似乎在所有组织中表达，并且在Ca 2+或Na+处理后AtHCX 1 RNA的水平增加。当在空泡Ca 2+摄取缺陷的酵母突变体中表达时，ZmHCX 1和AtHCX 1未能抑制这些菌株的Ca 2+敏感性。这些结果表明，CAX样基因可能有功能，在植物离子稳态，不同于那些以前的特点CAX基因。(C)2000 Elsevier Science B. V.保留所有权利。
Transporter-mediated Ca2+ efflux from the cytoplasm is an important component of plant signal transduction. To elucidate the diversity and role of Ca2+/H+ in controlling plant cytosolic Ca2+ concentrations, homologs of CAX (for calcium exchanger) genes were cloned from Zea mays and Arabidopsis thaliana cDNA libraries. The A. thaliana homolog of CAX (AtHCX1) is 77% identical to CAX1 while the Z. mays homolog of CAX (ZmHCX1) is 64% identical to CAX1 in amino acid sequence. AtHCX1 transcripts appeared to be expressed in all tissues, and levels of AtHCX1 RNA increased after Ca2+ or Na+ treatment. When expressed in yeast mutants defective in vacuolar Ca2+ uptake, ZmHCX1 and AtHCX1 failed to suppress the Ca2+ sensitivity of these strains. These results imply that CAX-like genes may have functions in plant ion homeostasis that differ from those of previously characterized CAX genes. (C) 2000 Elsevier Science B.V. All rights reserved.