Functional and physiological characterization of the Arabidopsis monosaccharide-transporter-like proteins At1g05030, At1g67300 and At1g79820 from endomembranes

拟南芥内膜单糖转运蛋白 At1g05030、At1g67300 和 At1g79820 的功能和生理学特征

• 批准号: 127037202
• 负责人: Professor Dr. Norbert Sauer
• 金额: --
• 依托单位: Department Biologie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2009
• 资助国家: 德国
• 起止时间: 2008-12-31 至 2012-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/127037202?language=en
• 关键词: Functional; physiological; characterization; Arabidopsis; monosaccharide

Arabidopsis has a large family (more than 50 members) of monosaccharide transporters (MST) and MST-like (MSTL) transporters that fall into 7 clearly distinguishable subgroups. All of these proteins are predicted to have 12 transmembrane (TM) helices. More than 50% of these proteins were characterized in our group and shown to catalyze the transport of different hexoses, or linear or cyclic polyols across the plasma membranes or across the tonoplast of different cell types. One of these seven subgroups with only four proteins contains one protein that localizes to plastids (At5g16150; AtpGlcT) and one protein that localizes to the Golgi (At1g79820; SGB1). In the proposed project we plan to study the two remaining, yet uncharacterized proteins of this subgroup, At1g05030 and At1g67300. In preliminary analyses we could show that these proteins are Golgi- (At1g05030) or tonoplast-localized (At1g67300). Moreover, we could demonstrate the existence of shorter, alternatively spliced mRNAs for At1g67300 and for the already published Golgi-localized transporter At1g79820 (SGB1). These shorter mRNAs encode proteins with only 6 TM-helices that were not observed for any of the previously studied proteins of the MSTL superfamily. We aim to functionally and physiologically characterize the proteins encoded by the At1g05030 and At1g67300 (12 TM) genes and to elucidate the role of the proteins encoded by the shorter transcripts of At1g67300 and At1g79820 (6 TM).

拟南芥具有单糖转运蛋白（MST）和MST样转运蛋白（MSTL）的大家族（超过50个成员），其分为7个明显可区分的亚组。预测所有这些蛋白质具有12个跨膜（TM）螺旋。超过50%的这些蛋白质的特征在于在我们的小组和催化运输不同的己糖，或线性或环状多元醇跨质膜或跨不同细胞类型的液泡膜。这七个亚群中只有四种蛋白质，其中一种蛋白质定位于质体（At 5g 16150; AtpGlcT），另一种蛋白质定位于高尔基体（At 1g 79820; SGB 1）。在拟议的项目中，我们计划研究该亚组中剩余的两种尚未表征的蛋白质，At 1g 05030和At 1g 67300。在初步分析中，我们可以表明，这些蛋白质是高尔基体（At 1g 05030）或液泡膜定位（At 1g 67300）。此外，我们可以证明存在较短的，选择性剪接的mRNA的At 1g 67300和已经发表的高尔基体定位的转运蛋白At 1g 79820（SGB 1）。这些较短的mRNA编码的蛋白质只有6个TM-螺旋，没有观察到任何以前研究的MSTL超家族的蛋白质。我们的目的是功能和生理特性的蛋白质编码的At 1g 05030和At 1g 67300（12 TM）基因，并阐明的作用，编码的蛋白质较短的转录本At 1g 67300和At 1g 79820（6 TM）。