Interaction between Agrobacterium tumefaciens oncoprotein 6b and a tobacco nucleolar protein that is homologous to TNP1 encoded by a transposable element of Antirrhinum majus
Interaction between Agrobacterium tumefaciens oncoprotein 6b and a tobacco nucleolar protein that is homologous to TNP1 encoded by a transposable element of Antirrhinum majus
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DOI：
10.1007/s10265-008-0160-1
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发表时间：
2008-07-01
影响因子：
2.8
通讯作者：
Machida, Yasunori
中科院分区：
文献类型：
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作者：
Kitakura, Saeko;Terakura, Shinji;Machida, Yasunori
当根癌农杆菌T-DNA上的基因6 b被转入植物细胞时，其表达引起体外培养中的植物细胞非依赖性分裂和异常细胞生长，从而诱导表达6 b的转基因拟南芥和烟草植物的各种形态缺陷。蛋白6 b定位于细胞核，这是异常细胞生长的必要条件，并与称为NtSIP 1和组蛋白H3的烟草核蛋白结合。此外，6 b在体外具有组蛋白伴侣样活性，并影响转基因拟南芥中各种植物基因的表达，包括细胞分裂相关基因和分生组织相关的1类KNOX同源框基因。在这里，我们报告说，6 b结合到一个新确定的蛋白NtSIP 2，其氨基酸序列被预测为30%相同和51%相似的TNP 1蛋白编码的转座子Tam 1金鱼草。使用抗T7抗体的免疫定位分析表明，大多数T7表位标记的NtSIP 2蛋白质的核仁定位。用T7标记的6 b蛋白进行的类似分析也显示了6 b蛋白的亚核仁以及核定位。这些结果表明，6 b沿着与NtSIP 2在某些分子过程中的核仁以及核质的参与。
When gene 6b on the T-DNA of Agrobacterium tumefaciens is transferred to plant cells, its expression causes plant hormone-independent division of cells in in vitro culture and abnormal cell growth, which induces various morphological defects in 6b-expressing transgenic Arabidopsis thaliana and Nicotiana tabacum plants. Protein 6b localizes to the nuclei, a requirement for the abnormal cell growth, and binds to a tobacco nuclear protein called NtSIP1 and histone H3. In addition, 6b has histone chaperone-like activity in vitro and affects the expression of various plant genes, including cell division-related genes and meristem-related class 1 KNOX homeobox genes, in transgenic Arabidopsis. Here, we report that 6b binds to a newly identified protein NtSIP2, whose amino acid sequence is predicted to be 30% identical and 51% similar to that of the TNP1 protein encoded by the transposon Tam1 of Antirrhinum majus. Immunolocalization analysis using anti-T7 antibodies showed nucleolar localization of most of the T7 epitope-tagged NtSIP2 proteins. A similar analysis with the T7-tagged 6b protein also showed subnucleolar as well as nuclear localization of the 6b protein. These results suggest the involvement of 6b along with NtSIP2 in certain molecular processes in the nucleolus as well as the nucleoplasm.