DdAlix, an Alix/AIP1 homolog in Dictyostelium discoideum, is required for multicellular development under low Ca2+ conditions.
DdAlix, an Alix/AIP1 homolog in Dictyostelium discoideum, is required for multicellular development under low Ca2+ conditions.
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DdAlix 是盘基网柄菌中的 Alix/AIP1 同源物，是低 Ca2 条件下多细胞发育所必需的。
DOI：
10.1016/j.gene.2004.04.020
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发表时间：
2004
期刊：
影响因子：
3.5
通讯作者：
M. Maki
中科院分区：
文献类型：
--
作者：
S. Ohkouchi;M. El;F. Aruga;H. Shibata;K. Hitomi;M. Maki
凋亡相关基因2(ALG-2)相互作用蛋白X(Alix)，又称AIP1，是真核生物中广泛保守的蛋白质。Alix及其同系物参与了多种现象，如细胞凋亡、细胞黏附调节、蛋白质分选、对应激条件的适应以及人类免疫缺陷病毒(HIV)的萌发。为了研究Alix在发育中的作用，我们在细胞黏菌盘基网柄菌中鉴定了一个Alix同源物，并通过同源重组扰乱了该基因。5 mM Li+对DdAlix缺失突变体(ALx−)细胞的生长有明显的抑制作用。在琼脂平板上，ALX−细胞发育正常，形成的子实体与野生型细胞形成的子实体难以区分。但在5 mM Li+存在下，ALX−细胞不能形成子实体。3，4，5-三甲氧基苯甲酸-8-(二乙氨基)辛酯(TMB-8)是细胞内钙离子储存的拮抗剂，在细胞发育过程中也得到类似的结果。此外，当细胞外游离钙离子降至10 nM时，ALx−细胞形成子实体的能力受到损害，但野生型细胞没有受到影响。这些结果表明，DdAlix在低钙条件下对发育是必需的，提示DdAlix参与了发育过程中的钙信号转导。
Apoptosis-linked gene 2 (ALG-2) interacting protein X (Alix), also called AIP1, is a widely conserved protein in eukaryotes. Alix and its homologs are involved in various phenomena such as apoptosis, regulation of cell adhesion, protein sorting, adaptation to stress conditions, and budding of human immunodeficiency virus (HIV). To investigate the role of Alix in development, we identified an Alix homolog in the cellular slime mold Dictyostelium discoideum and disrupted the gene by homologous recombination. The growth of DdAlix deletion mutant (alx−) cells was significantly impaired in the presence of 5 mM Li+. On an agar plate, alx−cells underwent normal development and formed fruiting bodies indistinguishable from those formed by wild-type cells. However, alx−cells could not form fruiting bodies in the presence of 5 mM Li+. Similar results were obtained when cells were developed in the presence of 3,4,5-trimethoxybenzoic acid 8-(diethylamino)octyl ester (TMB-8), which is an antagonist of intracellular Ca2+store. Furthermore, when the extracellular free Ca2+was reduced to 10 nM, the ability of alx−cells, but not that of wild-type cells, to form fruiting bodies was impaired. The results indicate that DdAlix is essential for development under low Ca2+conditions and suggest that DdAlix is involved in Ca2+signaling during development.