Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, S-90187, Umeå, Sweden; Umeå Plant Science Centre, Department of Plant Physiology, Umeå University, S-90183, Umeå, Sweden; UMR 1318, AgroParisTech, Institut Jean-Pierre Bourgin, Institut National de la Recherche Agronomique Centre de Versailles, RD10, 78026, Versailles Cedex, France.
Plant J. 2013 Dec;76(5):811-24. doi: 10.1111/tpj.12334.
In order to obtain insights into the regulatory pathways controlling phloem development, we characterized three genes encoding membrane proteins from the G sub-family of ABC transporters (ABCG9, ABCG11 and ABCG14), whose expression in the phloem has been confirmed. Mutations in the genes encoding these dimerizing 'half transporters' are semi-dominant and result in vascular patterning defects in cotyledons and the floral stem. Co-immunoprecipitation and bimolecular fluorescence complementation experiments demonstrated that these proteins dimerize, either by flexible pairing (ABCG11 and ABCG9) or by forming strict heterodimers (ABCG14). In addition, metabolome analyses and measurement of sterol ester contents in the mutants suggested that ABCG9, ABCG11 and ABCG14 are involved in lipid/sterol homeostasis regulation. Our results show that these three ABCG genes are required for proper vascular development in Arabidopsis thaliana.
为了深入了解控制韧皮部发育的调控途径，我们对编码 ABC 转运蛋白 G 亚家族膜蛋白的三个基因（ABCG9、ABCG11 和 ABCG14）进行了特征分析，这些基因的表达已在韧皮部得到证实。编码这些二聚“半转运蛋白”的基因突变是半显性的，导致子叶和花茎中的血管模式缺陷。共免疫沉淀和双分子荧光互补实验表明，这些蛋白通过灵活配对（ABCG11 和 ABCG9）或形成严格的异二聚体（ABCG14）进行二聚化。此外，代谢组学分析和突变体甾醇酯含量的测量表明，ABCG9、ABCG11 和 ABCG14 参与脂质/甾醇稳态调节。我们的结果表明，这三个 ABCG 基因在拟南芥中正常的血管发育中是必需的。
