Michigan State University-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI 48824, USA.
J Exp Bot. 2011 Oct;62(14):4917-26. doi: 10.1093/jxb/err174. Epub 2011 Jun 24.
Eukaryotic cells use COPII-coated carriers for endoplasmic reticulum (ER)-to-Golgi protein transport. Selective cargo capture into ER-derived carriers is largely driven by the SEC24 component of the COPII coat. The Arabidopsis genome encodes three AtSEC24 genes with overlapping expression profiles but it is yet to be established whether the AtSEC24 proteins have overlapping roles in plant growth and development. Taking advantage of Arabidopsis thaliana as a model plant system for studying gene function in vivo, through reciprocal crosses, pollen characterization, and complementation tests, evidence is provided for a role for AtSEC24A in the male gametophyte. It is established that an AtSEC24A loss-of-function mutation is tolerated in the female gametophyte but that it causes defects in pollen leading to failure of male transmission of the AtSEC24A mutation. These data provide a characterization of plant SEC24 family in planta showing incompletely overlapping functions of the AtSEC24 isoforms. The results also attribute a novel role to SEC24 proteins in a multicellular model system, specifically in male fertility.
真核细胞利用 COPII 被膜小泡运输内质网（ER）到高尔基体的蛋白。选择性货物捕获到 ER 衍生的载体主要由 COPII 被膜的 SEC24 组成部分驱动。拟南芥基因组编码三个 AtSEC24 基因，具有重叠的表达谱，但尚不清楚 AtSEC24 蛋白在植物生长和发育中是否具有重叠的作用。利用拟南芥作为研究体内基因功能的模式植物系统，通过回交、花粉特征分析和互补测试，为 AtSEC24A 在雄性配子体中的作用提供了证据。研究结果表明，AtSEC24A 功能丧失突变在雌性配子体中是可以耐受的，但它会导致花粉缺陷，从而导致 AtSEC24A 突变的雄性传递失败。这些数据提供了植物 SEC24 家族在体内的特征，显示了 AtSEC24 同工型的功能不完全重叠。研究结果还赋予了 SEC24 蛋白在多细胞模型系统中的新作用，特别是在雄性育性方面。
