Characterization and expression analyses of two plastidic enolase genes in rice
Characterization and expression analyses of two plastidic enolase genes in rice
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DOI：
10.1080/09168451.2014.980219
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发表时间：
2015-03-04
影响因子：
1.6
通讯作者：
Miyao, Mitsue
中科院分区：
文献类型：
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作者：
Fukayama, Hiroshi;Masumoto, Chisato;Miyao, Mitsue
为了验证与水稻叶绿体糖酵解相关的烯醇酶的存在，进行了数据库搜索，并在水稻基因组中鉴定了7个可能的烯醇酶基因。其中，OsEno1和OsEno3编码N-末端延伸的长蛋白。这些N-末端延伸的GFP蛋白融合都是针对洋葱表皮细胞的质体。启动子：：GUS分析表明，OsEno3在幼叶中高度表达，但在叶片发育和绿化过程中表达急剧下降。另一方面，OsEno1的表达水平较低，仅在分蘖根部的叶鞘等部位有表达。重组OsEno1蛋白具有烯醇酶活性，最适pH为8.0，而OsEno3没有检测到活性。虽然目前还不清楚OsEno3是否在体内编码一个功能性的烯醇化酶，但我们的结果表明，整个糖酵解途径并不在水稻叶绿体中起作用。
To verify the presence of enolase related to the chloroplastic glycolysis in rice, database search was carried out and identified seven putative enolase genes in the rice genome. Among them, OsEno1 and OsEno3 encode long proteins with N-terminal extensions. GFP protein fusions of these N-terminal extensions were both targeted to plastids of onion epidermal cell. Promoter::GUS analysis showed that OsEno3 was highly expressed in young developing leaves, but its expression was drastically decreased during leaf development and greening. On the other hand, the expression of OsEno1 was low and detected in limited portions such as leaf sheath at the tiller base. Recombinant OsEno1 protein showed enolase activity with a pH optimum at pH 8.0, whereas OsEno3 did not exhibit detectable activity. Although it remains obscure if OsEno3 encodes a functional enolase in vivo, our results demonstrate that the entire glycolytic pathway does not operate in rice chloroplasts.