Molecular basis of cellular functions in Dictyostelium

盘基网柄菌细胞功能的分子基础

• 批准号: 10044192
• 负责人: MAEDA Yasuo
• 金额: $ 4.8万
• 依托单位: Tohoku University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B).
• 财政年份: 1998
• 资助国家: 日本
• 起止时间: 1998 至 2000
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-10044192/
• 关键词: cell cycle; PS point; differentiation; pattern formation; starvation; Turing model; Chemotaxis; Dictyostelium; 細胞質分裂; ミトコンドリア; 飢餓応答

(1) Using the good method for cell synchrony, three genes (dia1, dia2, dia3) were isolated and identified as ones specifically expressed during the transition of Dictyostelium cells from growth to differentiation. Analyses of their functions have revealed that in response to starvation the expressions of a novel gene, dia2, and a mitochondrial gene cluster (dia3) including rps4 are required for the initiation of cell differentiation from the growth/differentiation checkpoint (PS point) in the cell cycle, but that the expression of a novel gene (dia 1) rather inhibits temporally the progression of differentiation from the PS point. In addition, a novel gene, amiB, was also found to be required for the transition of cells from growth to differentiation.(2) The signals for starvation response in Dictyostelium cells have been shown to be transduced through a temporally elevated cytoplasmic Ca2+-concentration ([Ca2+]i). In this connection, it was suggested that Dd-GRP94 (Dictyostelium gluco … More se-regulated protein 94) might be cruial in late differentiation as well as in starvation response. During the course of studies, some phosphoproteins resaonsible for starvation response were also found(3) The mitochondrion was Immunoelectron-microscopically found to be participated in the formation of a cell-type-specific organelle (PSV ; presnore-specific vacuole) as the structural basis, coupling with the Golgi complex.(4) Rappid patterning has been observed in confined 2-D cultures of D.discoideum Ax-2 cells as an outer dark zone and a inner light zone : the outer zone is basically formed by the O2 threshold for oxidative phosphorylation, while the inner cells mainly perform cyanide-resistant respiration. When cells around the early mound stage (just before prestalk and prespore differentiation) were cultured in 2-D cell masses, pstA cells, pstB cells and prespore cells arose in a position-dependent manner in the outer layer. In the inner zone, cell motility seemed to be markedly impared and neither prestalk nor prespore differentiation occurred. In sddition, once-differentiated prespore cells were found to dedifferentiate ranidly in the inr zone.(5) A new type of rappid paterning as observed in a 2-D confined cell mass of D.discoideum is formed due to a reaction-diffusion Turing instability. This may be the first biochemical structure in a developmental system with a controllable boundary condition. Less

(1)利用细胞同步化的良好方法，分离到三个基因(dia1、dia2、dia3)，并鉴定为Dictyostelius细胞从生长到分化过程中特异表达的基因。对它们功能的分析表明，在饥饿反应中，一个新基因dia2和包括RPS4在内的线粒体基因簇(Dia3)的表达是细胞周期中从生长/分化检查点(PS Point)启动细胞分化所必需的，但一个新基因(Dia 1)的表达反而暂时抑制了从PS点开始的分化进程。此外，一个新的基因amiB也被发现是细胞从生长到分化所必需的。(2)Dictyostelials细胞的饥饿反应信号是通过细胞质内短暂升高的钙离子浓度([Ca2+]i)来传递的。在这方面，有人建议将DD-GRP94(DictyostelialGLuco…更多的Se调节蛋白94)可能在后期分化和饥饿反应中起关键作用。在研究过程中，还发现了一些与饥饿反应有关的磷酸蛋白。(3)免疫电子显微镜观察发现，线粒体参与了作为结构基础的细胞型特异性细胞器(PSV；prenore-Specitive Laveol)的形成，并与高尔基复合体结合。(4)在盘状螺旋藻Ax-2细胞有限的二维培养中，观察到快速图案作为外暗区和内光区：外区主要由氧化磷酸化的O2阈值形成，而内细胞主要进行抗氰化物呼吸。在2-D细胞团中培养早期丘状细胞(前柄和前孢子分化前)，PSTA细胞、PstB细胞和前孢子细胞在外层以位置依赖的方式出现。内区细胞活力明显受损，无柄前分化和孢子前分化。在此条件下，一次分化的前孢子细胞在INR区粗大地脱分化。(5)由于反应-扩散图灵不稳定性，在盘状盘藻的二维受限细胞团中观察到了一种新的裂隙模式。这可能是发育系统中第一个具有可控边界条件的生化结构。较少

项目成果

Hirose S. et al.: "Suppression of the growth /differentiation transition in Dictyostelium development by transient expression of dia1"Development. 127. 3263-3270 (2000)

Hirose S.等人：“通过dia1的瞬时表达抑制盘基网柄菌发育中的生长/分化转变”开发。

Kon, T., Adachi, H.and Sutoh, K.: "amiB, a novel gene required for the growth/differentiation transition in Dictyostelium"Genes Cells. 5. 43-55 (2000)

Kon, T.、Adachi, H. 和 Sutoh, K.：“amiB，盘基网柄菌生长/分化转变所需的新基因”基因细胞。

Inazu,Y. et al.: "Transient expression of a mitochondrial gene cluster including rps4 is essential for phase-shift of Dictyostelium cells"Develop Genetics. 25. 339-352 (1999)

稻津，Y.

Hirose,S. et al.: "Suppression of the growth differentiation transition in Dictyostelium development by transient expression of dial."Development. 127. 3263-3270 (2000)

广濑，S.

前田靖男(編): "モデル生物:細胞性粘菌"アイピーシー(IPC). 386 (2000)

Yasuo Maeda（编辑）：“模型生物：细胞盘基网柄菌”IPC 386 (2000)。