毒素子AAP7对于功能性地将IMC嵌入的顶端环连接到血膜至关重要
Ciara N Bauwens1, Klemens Engelberg1, Marc-Jan Gubbels1
1Department of Biology, Boston College, Chestnut Hill, Massachusetts, US.
bioRxiv : the preprint server for biology
|November 19, 2025
概括
一种新型蛋白质,AAP7,对于Toxoplasma gondii的健康至关重要,使密集的颗粒分泌和LMBD3的适当贩运成为可能. 它的缺失会导致严重的缺陷,包括改变真空球形成和微管动力学.
科学领域:
- 细胞生物学 细胞生物学
- 寄生虫学的寄生虫学
- 微生物学 微生物学
背景情况:
- 毒素菌细胞骨架具有内膜复合体 (IMC) 和圆环,对于密集颗粒外细胞形成至关重要.
- 这些尖端环状环形是参与分泌效应蛋白质的环状毛孔.
研究的目的:
- 描述一种新型的尖端环蛋白蛋白,AAP7,并阐明其在Toxoplasma gondii中的功能.
- 了解AAP7在蛋白质贩运,器官细胞功能和寄生虫健康方面的作用.
主要方法:
- 在Toxoplasma gondii寄生虫中AAP7的耗尽.
- 使用显微镜分析蛋白质贩运 (LMBD3局部化).
- 对密集颗粒分泌 (GRA17) 和真空球形态的评估.
- 研究皮膜下微管体 (SPMT) 动态.
- 在Sarcocystis神经中对尖端环状细胞进行比较分析.
主要成果:
- AAP7的枯竭严重影响了寄生虫的健康状况和LMBD3的贩运到顶环.
- 密集颗粒蛋白GRA17的分泌量减少导致特有的"泡"真空孔.
- 过度表达GRA17拯救了AAP7枯竭表型,突出了它的关键作用.
- 由于AAP7的耗尽,多聚氨基胺基的积累,这表明周转率受损.
- 对比分析显示,在Sarcocystis neurona中,有6个顶端环,独立于膜囊泡数量.
结论:
- AAP7对于圆环的功能,LMBD3的贩运和Toxoplasma gondii中的GRA17分泌是必不可少的.
- 这项研究揭示了一条新的贩运途径,涉及AAP7及其与IMC的联系.
- AAP7在调节SPMT营业额方面发挥着作用.
- 圆环结构不是由IMC接位置决定的,这挑战了以前的假设.
相关概念视频
01:27Diversity of Protists II
754
Alveolates are a group of organisms recognized by the presence of alveoli, which are cytoplasmic sacs located beneath the cell membrane. While their function remains uncertain, alveoli may help regulate water balance by controlling how much water enters and leaves the cell. In dinoflagellates, these structures may serve as armor plates. There are three major types of alveolates: ciliates, which move using cilia; dinoflagellates, which use flagella for movement; and apicomplexans, which are...
754
01:42The ADP/ATP Carrier Protein
4.1K
ADP/ATP carrier or AAC protein is the most abundant carrier protein in the inner mitochondrial membrane. It transports large quantities of ADP and ATP, equivalent to the average human body weight, every day. Among other transporters, ACC protein is one of the best-studied members of the mitochondrial carrier protein family. The ADP/ATP carrier protein comprises two transmembrane helices connected to a loop and a single alpha-helix on the matrix side. It switches between two conformational...
4.1K
01:19Translocation of Proteins into the Mitochondria
11.9K
Mitochondrial precursors are translocated to the internal subcompartments via independent mechanisms involving distinct protein machineries called translocases.
Sorting of outer membrane proteins:
Mitochondrial outer membrane proteins are of two types: the transmembrane, beta-barrel porins, and the membrane-anchored, alpha-helical proteins. Beta-barrel porin precursors are translocated by the TOM complex and inserted into the outer mitochondrial membrane by the SAM complex. In contrast,...
Sorting of outer membrane proteins:
Mitochondrial outer membrane proteins are of two types: the transmembrane, beta-barrel porins, and the membrane-anchored, alpha-helical proteins. Beta-barrel porin precursors are translocated by the TOM complex and inserted into the outer mitochondrial membrane by the SAM complex. In contrast,...
11.9K
01:21Structure of Porins
3.8K
Mitochondria, chloroplasts, and gram-negative bacteria have transmembrane, beta-barrel proteins called porins to mediate the free diffusion of ions and metabolites across the membrane. Mitochondrial porin precursors contain conserved amino acid sequences called beta signals at their C-terminal. Beta signals have a motif of PoXGXXHyXHy (Po-Polar, X-Any amino acid, G-Glycine, Hy-LargeHydrophobic), which are crucial for precursor recognition to initiate precursor assembly. Beta-barrel...
3.8K
01:42Microtubule Associated Proteins (MAPs)
5.7K
Microtubule function and architecture are regulated by an array of specialized proteins called microtubule-associated proteins or MAPs. These proteins are widespread across different organisms and have conserved protein motifs, like the multi-TOG domain for tubulin binding found in the CLASP family of MAPs. Some MAPs are lineage-specific based on their conserved domains. Their functions depend upon the cytoskeletal architecture and cell type they are located within. In-plant cells, a specific...
5.7K
01:32Assembly of Complex Microtubule Structures
2.4K
Complex microtubule structures are present in resting cells and in dividing cells. In resting cells, they are responsible for maintaining the cellular architecture, tracks for intracellular transport, positioning of organelles, assembly of cilia and flagella. They mediate the bipolar spindle assembly for chromosomal segregation and positioning of the cell division plate in dividing cells. The formation of microtubule complex structures depends on the cell type, cell stage, and cell function.
2.4K