Lotus japonicus gene ljsbp is highly conserved among plants and animals and encodes a homologue to the mammalian selenium-binding proteins
Lotus japonicus gene ljsbp is highly conserved among plants and animals and encodes a homologue to the mammalian selenium-binding proteins
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DOI：
10.1094/mpmi.2002.15.4.313
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发表时间：
2002-04-01
影响因子：
3.5
通讯作者：
Katinakis, P
中科院分区：
文献类型：
--
作者：
Flemetakis, E;Agalou, A;Katinakis, P
我们已经分离并鉴定了Lotus的一个硒结合蛋白基因（Ljsbp），该基因编码一种推定的多肽，与哺乳动物的56-kDa硒结合蛋白（SBP）具有惊人的同源性。还从大豆、紫花苜蓿和拟南芥中分离到与LjSBP同源的cDNA克隆。在L.和A. thaliana表明sbp转录本存在于各种组织中和不同水平。特别是在L。结瘤、种荚和A.在拟南芥长角果中，SBP表达似乎在发育过程中上调。原位杂交结果表明，sbp基因转录本在幼根瘤的侵染细胞和维管束中均有表达，而在成熟根瘤中，仅在薄壁细胞中有低水平表达。在幼果和角果中，sbp转录本的表达在维管组织和胚中清晰可见，而在胚中，在根表皮和维管束中检测到低水平的表达。针对截短的LjSBP重组蛋白提出的多克隆抗体识别结节提取物中约60 kDa的多肽。免疫组织化学实验表明，LjSBP的积累发生在根毛，在根瘤原基以上的根表皮，在韧皮部的维管系统，并在年轻的结节感染细胞丰富。无论根瘤菌的存在，SBP的表达也观察到在根尖，在那里它被限制在根表皮和原生韧皮部细胞。我们推测，LjSBP可能有一个以上的生理作用，并可能涉及控制目标蛋白的氧化/还原状态，在囊泡高尔基体运输，或两者兼而有之。
We have isolated and characterized a Lotus japonicus gene (Ljsbp) encoding a putative polypeptide with striking homology to the mammalian 56-kDa selenium-binding protein (SBP). cDNA clones homologous to LjSBP were also isolated from soybean, Medicago sativa, and Arabidopsis thaliana. Comparative expression studies in L japonicus and A. thaliana showed that sbp transcripts are present in various tissues and at different levels. Especially in L. japonicus nodules and seedpods and A. thaliana siliques, sbp expression appears to be developmentally up-regulated. sbp Gene transcripts were localized by in situ hybridization in the infected cells and vascular bundles of young nodules, while in mature nodules, low levels of expression were only detected in the parenchymatous cells. Expression of sbp transcripts in young seedpods and siliques was clearly visible in vascular tissues and embryos, while in embryos, low levels of expression were detected in the root epidermis and the vascular bundles. Polyclonal antibodies raised against a truncated LjSBP recombinant protein recognized a polypeptide of about 60 kDa in nodule extracts. Immunohistochemical experiments showed that accumulation of LjSBP occurred in root hairs, in the root epidermis above the nodule primordium, in the phloem of the vasculature, and abundantly in the infected cells of young nodules. Irrespective of the presence of rhizobia, expression of SBP was also observed in root tips, where it was confined in the root epidermis and protophloem cells. We hypothesize that LjSBP may have more than one physiological role and can be implicated in controlling the oxidation/reduction status of target proteins, in vesicular Golgi transport, or both.