Institut Pasteur, Unité Biologie Cellulaire du Parasitisme, Paris, France.
INSERM Unit 786, Paris, France.
Cell Microbiol. 2019 Apr;21(4):e12983. doi: 10.1111/cmi.12983. Epub 2018 Dec 21.
Actin is one of the most conserved, abundant, and ubiquitous proteins in all eukaryotes characterised to date. Posttranslation modifications of actin modify the organisation of the actin-rich cytoskeleton. In particular, chemical modifications of actin's amino-terminal region determine how filamentous actin is organised into scaffolds. After assuming that protein modifications account for the multiple functional activities exerted by the single actin in Entamoeba histolytica, we profiled posttranslational modifications of this protein. Acetylation (on 21 different amino acids) was the most abundant modification, followed by phosphorylation. Furthermore, the glycine residue at Position 2 in E. histolytica's actin (Gly2, not found in most other eukaryotic actins) was found to be acetylated. The impact of Gly2 on the amoeba's life cycle and pathogenicity was then assessed in mutagenesis experiments. We found that Gly2 was necessary for cell morphology and division, parasite-host cell adhesion, and host invasion in an in vitro model of amoebic human infection.
肌动蛋白是目前为止在所有真核生物中最保守、最丰富和最普遍存在的蛋白质之一。肌动蛋白的翻译后修饰改变了富含肌动蛋白的细胞骨架的组织。特别是，肌动蛋白氨基末端区域的化学修饰决定了丝状肌动蛋白如何组织成支架。在假设蛋白质修饰解释了溶组织内阿米巴中单个肌动蛋白发挥的多种功能活动之后，我们对该蛋白的翻译后修饰进行了分析。乙酰化（在 21 个不同的氨基酸上）是最丰富的修饰，其次是磷酸化。此外，在溶组织内阿米巴肌动蛋白的位置 2 的甘氨酸残基（Gly2，在大多数其他真核肌动蛋白中未发现）被发现被乙酰化。然后，在突变实验中评估了 Gly2 对阿米巴生命周期和致病性的影响。我们发现 Gly2 对于细胞形态和分裂、寄生虫-宿主细胞粘附以及体外阿米巴人类感染模型中的宿主侵袭是必需的。
