Proteomic analysis of rice embryo:: An approach for investigating Gα protein-regulated proteins
Proteomic analysis of rice embryo:: An approach for investigating Gα protein-regulated proteins
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DOI：
10.1002/pmic.200401237
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发表时间：
2005-10-01
期刊：
影响因子：
3.4
通讯作者：
Iwasaki, Y
中科院分区：
文献类型：
--
作者：
Komatsu, S;Abbasi, F;Iwasaki, Y
水稻矮秆（d1）突变体缺少异源三聚体G蛋白（Got蛋白）的a亚基，节间缩短，叶片深绿色，籽粒小而圆，形态异常。在本研究中，蛋白质组学分析有助于确定G α蛋白在水稻胚胎中的功能。利用2-DE分析，与野生型相比，d1突变体中有7种种子胚蛋白下调。这7种蛋白包括活化c -激酶受体（RACK）和6种水稻胚球蛋白-2蛋白（REG2）。6种REG2具有相似的分子质量，但pI有微小差异。除了d1突变体中RACK的积累减少外，与野生型相比，表达Ga蛋白组成活性形式的QL/d1的增加显著高于野生型。这7种蛋白在种子发育和成熟过程中的积累水平直到授粉后第2周才发生显著变化。d1突变体在授粉后第3周开始减少这7种蛋白质的积累，并一直持续到种子成熟完成。d1突变体和野生型在吸胀24 h后，这7种蛋白完全缺失。然而，与d1突变体相比，植物激素脱落酸促进了野生型吸胀后RACK的表达水平。这些结果表明，RACK受ga蛋白调控，在水稻胚发生和萌发的基本细胞过程中起重要作用。
The rice dwarfl (d1) mutant, which lacks the a subunit of a heterotrimeric G protein (Got protein), shows abnormal morphology due to shortened internodes, dark green leaves and grains that are small and round. Proteome analysis was used in this study to aid in determining the function of G alpha protein in rice embryos. Using 2-DE, seven seed embryo proteins were shown to be down-regulated in the d1 mutant as compared with its wild type. These seven proteins included a receptor for activated C-kinase (RACK) and six rice embryo globulin-2 proteins (REG2). The six REG2 have similar molecular masses with minor differences in pI. In addition to the reduced accumulation of RACK in the d1 mutant, the increase in QL/d1, in which a constitutively active form of the Ga protein is expressed, was significantly higher as compared with wild type. The level of accumulation of these seven proteins during seed development and maturation did not change significantly until the 2nd wk after pollination. Reduced accumulation of these seven proteins started in the d1 mutant at the 3rd wk after pollination, and continued until seed maturation was complete. All seven proteins were completely absent 24 h after imbibition in both d1 mutant and its wild type. However, the phytohormone abscisic acid promoted the expression level of RACK after imbibition in the wild type as compared with d1 mutant. These results suggest that RACK is regulated by Ga-protein and plays an important role in a basic cellular process as well as in rice embryogenesis and germination.