Polarized growth and the role of apical sterol-rich domains in Aspergillus nidulans

构巢曲霉的极化生长和顶端甾醇丰富结构域的作用

• 批准号: 215187193
• 负责人: Dr. Norio Takeshita
• 金额: --
• 依托单位: Abteilung Mikrobiologie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2012
• 资助国家: 德国
• 起止时间: 2011-12-31 至 2015-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/215187193?language=en
• 关键词: Polarized; growth; role; apical; sterol

Polarized growth of filamentous fungi depends on the microtubule (MT) and the actin cytoskeleton along with their associated motor proteins. Tip membrane-associated landmark proteins, so-called “cell end markers” link the two cytoskeletons. Recent results indicate that apical sterol-rich membrane domains (SRDs) play important roles in polarized growth and localization of cell end markers. SRDs are specific to fungi and thought to be formed by lipid raft clustering. In our preliminary study, we revealed that a flotillin orthologue, FloA, which serves as scaffold for raft formation at the membrane, is involved in the formation of SRDs. With the proposed research we are aiming to analyze the localization of SRDs (distribution of lipid raft clusters) in detail by super-resolution microscopy using FloA as a raft marker. To investigate the formation mechanism of SRDs, some candidate genes (actin-lipid binding proteins) are going to be analyzed by gene deletion and fluorescent protein tagging. To identify new genes involved in SRDs formation, genetic screens for multi-copy suppressors of sphingolipid synthesis mutants will be performed. To analyze the roles of SRDs on the integrity of the cytoskeletons, cell end markers, and growth machinery, we will analyze their localization in corresponding mutants of the genes identified in the reverse-genetic and the suppressor analysis.

丝状真菌的极化生长依赖于微管（MT）和肌动蛋白细胞骨架沿着及其相关的马达蛋白。顶端膜相关的标志性蛋白质，所谓的“细胞末端标记”连接两个细胞骨架。最近的研究结果表明，顶端甾醇丰富的膜结构域（SRDs）在极化生长和细胞末端标记的定位中起着重要作用。SRD是真菌特有的，被认为是由脂筏聚集形成的。在我们的初步研究中，我们发现，一个flotillin的直系同源物，FloA，它作为支架的筏形成在膜上，参与形成SRD。通过拟议的研究，我们的目标是使用FloA作为筏标记物，通过超分辨率显微镜详细分析SRD（脂筏簇的分布）的定位。为了研究SRD的形成机制，将通过基因缺失和荧光蛋白标记来分析一些候选基因（肌动蛋白-脂质结合蛋白）。为了鉴定参与SRD形成的新基因，将对鞘脂合成突变体的多拷贝抑制因子进行遗传筛选。为了分析SRD对细胞骨架、细胞末端标记和生长机制完整性的作用，我们将分析它们在反向遗传和抑制分析中鉴定的基因的相应突变体中的定位。