Bassham D C, Gal S, da Silva Conceição A, Raikhel N V
Department of Energy Plant Research Laboratory, Michigan State University, East Lansing 48824-1312, USA.
Proc Natl Acad Sci U S A. 1995 Aug 1;92(16):7262-6. doi: 10.1073/pnas.92.16.7262.
The syntaxin family of integral membrane proteins are thought to function as receptors for transport vesicles, with different isoforms of this family localized to various membranes throughout the cell. The yeast Pep12 protein is a syntaxin homologue which may function in the trafficking of vesicles from the trans-Golgi network to the vacuole. We have isolated an Arabidopsis thaliana cDNA by functional complementation of a yeast pep12 mutant. The Arabidopsis cDNA (aPEP12) potentially encodes a 31-kDa protein which is homologous to yeast Pep12 and to other members of the syntaxin family, indicating that this protein may function in the docking or fusion of transport vesicles with the vacuolar membrane in plant cells. Northern blot analysis indicates that the mRNA is expressed in all tissues examined, although at a very low level in leaves. The mRNA is found in all cell types in roots and leaves, as shown by in situ hybridization experiments. The existence of plant homologues of proteins of the syntaxin family indicates that the basic vesicle docking and fusion machinery may be conserved in plants as it is in yeast and mammals.
整合膜蛋白的 syntaxin 家族被认为作为运输小泡的受体发挥作用，该家族的不同异构体定位于细胞内的各种膜上。酵母 Pep12 蛋白是一种 syntaxin 同源物，可能在从反式高尔基体网络到液泡的小泡运输中起作用。我们通过对酵母 pep12 突变体的功能互补分离出了拟南芥 cDNA。拟南芥 cDNA（aPEP12）可能编码一种 31 kDa 的蛋白质，它与酵母 Pep12 以及 syntaxin 家族的其他成员同源，这表明该蛋白质可能在植物细胞中运输小泡与液泡膜的对接或融合中发挥作用。Northern 印迹分析表明，在所检测的所有组织中均有该 mRNA 表达，尽管在叶片中的表达水平非常低。原位杂交实验表明，在根和叶的所有细胞类型中都能发现该 mRNA。syntaxin 家族蛋白质的植物同源物的存在表明，基本的小泡对接和融合机制在植物中可能像在酵母和哺乳动物中一样保守。
