Isotypes of multilocalizing proteins from the cytoskeleton and their roles in differentiation and growth of pea seedlings.

研究了豌豆细胞骨架中肝素结合蛋白SN4TDR和APY1的表达、定位和分子结构。SN4TDR和apy1均定位于豌豆幼苗组织的细胞质中，并在侧根形成的原基中被诱导。在一些活跃的细胞中，apy1也定位于细胞核。然而，SN4TDR在吸胀过程中被诱导表达，并在萌发后保持不变，而apy1在萌发16h后被诱导表达。用免疫组织化学方法证实了这些蛋白在豌豆幼苗细胞质中的定位。当完整的SN4TDR与XFP融合并在S.pombe中表达时，该蛋白被证明定位于细胞质中，使细胞核在整个生命周期(营养、交配和产孢子)中不被染色。对S.pombe中YFP结构的缺失实验表明，SN4TDR中存在长度小于50aa的核排斥信号(NES)。酵母双杂交结合免疫沉淀，提出翻译起始因子微管蛋白结合亚单位moe1和核糖体蛋白L22可作为体内结合SN4TDR的候选基因。同时也证实了apy1的磷酸化。

Expression, localization, and molecular structure of the heparin binding protein SN4TDR and apy1 from the pea cytoskeleton were studied. Both SN4TDR and apy1 were localized in the cytoplasm in pea seedling tissues and also induced in the primodium for lateral root formation. In some active cells, apy1 was also localized in nuclei. However, expression of SN4TDR was induced during imbibition and kept constant after germination as in tub1, while apy1 was induced 16 h after germination. Localization of these proteins in the cytoplasm were proved by immunohistochemistry in pea seedlings. When with the full SN4TDR was fused with XFP and expressed in S.pombe, the protein was proved to localize in cytoplasm, leaving nuclei unstained throughout the life cycle (vegetative, mating, and sporulation. Deletion experiments of the YFP construct in S.pombe implied the presence of nuclear exclusion signal (NES) with less than 50 aa long in SN4TDR. Yeast two hybridization followed by immunoprecipitation.proposed the tubulin binding subunit of translation initiation factor, moe1 and ribosomal protein L22 potent as candidates for association of SN4TDR in vivo. Phosphorylation of apy1 was also proved.