AN INTRINSIC TONOPLAST PROTEIN OF PROTEIN STORAGE VACUOLES IN SEEDS IS STRUCTURALLY RELATED TO A BACTERIAL SOLUTE TRANSPORTER (GLPF)
AN INTRINSIC TONOPLAST PROTEIN OF PROTEIN STORAGE VACUOLES IN SEEDS IS STRUCTURALLY RELATED TO A BACTERIAL SOLUTE TRANSPORTER (GLPF)
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DOI：
10.1105/tpc.2.6.525
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发表时间：
1990-06-01
期刊：
影响因子：
11.6
通讯作者：
CHRISPEELS, MJ
中科院分区：
文献类型：
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作者：
JOHNSON, KD;HOFTE, H;CHRISPEELS, MJ
液泡膜介导的液泡和胞质溶胶之间的各种离子和代谢产物的运输机制，仍有待阐明在分子水平上。到目前为止，只有一种液泡膜蛋白H+-ATPase的一级结构被报道。在这里，我们报道了液泡膜内在蛋白（TIP）的一级结构，TIP是一种27千道尔顿的内在膜蛋白，广泛存在于种子的蛋白质储存液泡（蛋白体）的液泡膜中[Hohnson，K.D.，等（1989）。Plant Physiol.91，1006-1013]。亲水性图和二级结构分析的多肽预测6个跨膜结构域连接的短循环和亲水性，细胞质导向的N-和C-末端区域。TIP与其他几种不同来源的膜蛋白具有显著的同源性：牛透镜纤维质膜的主要内在多肽; NOD 26，大豆固氮根瘤中的周类细菌膜蛋白;有趣的是，GlpF，土方大肠杆菌细胞质膜中的甘油促进剂转运蛋白。基于TIP和GlpF之间的同源性以及蛋白质贮藏液泡膜和类菌周膜在溶质转运中具有活性的知识，我们提出TIP在种子贮藏组织的贮藏液泡和细胞质之间转运小的代谢物。
The tonoplast mediates the transport of various ions and metabolites between the vacuole and cytosol by mechanisms that remain to be elucidated at the molecular level. The primary structure of only one tonoplast protein, the H+-ATPase, has been reported to date. Here we report the primary structure of tonoplast intrinsic protein (TIP), a 27-kilodalton intrinsic membrane protein that occurs widely in the tonoplasts of the protein storage vacuoles (protein bodies) of seeds [Hohnson, K.D., et al. (1989). Plant Physiol. 91, 1006-1013]. Hydropathy plots and secondary structure analysis of the polypeptide predict six membrane-spanning domains connected by short loops and hydrophilic, cytoplasmically oriented N- and C-terminal regions. TIP displays significant homology with several other membrane proteins from diverse sources: major intrinsic polypeptide from bovine lens fiber plasma membrane; NOD 26, a peribacteroid membrane protein in the nitrogen-fixing root nodules of soybean; and interestingly, GlpF, the glycerol facilitator transport protein in the cytoplasmic membrane of Escherchia coli. Based on the homology between TIP and GlpF and the knowledge that the protein storage vacuolar membrane and the peribacteroid membrane are active in solute transport, we propose that TIP transport small metabolites between the storage vacuoles and cytoplasm of seed storage tissues.