Univ. Bordeaux, INRAE, Biologie du Fruit et Pathologie, UMR 1332, 33140, Bordeaux, Villenave d'Ornon, France.
Univ. Bordeaux, CNRS, INSERM, Bordeaux Imaging Center, BIC, UMS 3420, US 4, 33140, Bordeaux, Villenave d'Ornon, France.
Sci Rep. 2021 May 27;11(1):11222. doi: 10.1038/s41598-021-90809-z.
The flavescence dorée phytoplasma undergoes a propagative cycle in its insect vectors by first interacting with the insect cell surfaces, primarily in the midgut lumen and subsequently in the salivary glands. Adhesion of flavescence dorée phytoplasma to insect cells is mediated by the adhesin VmpA. We hypothesize that VmpA may have lectin-like activity, similar to several adhesins of bacteria that invade the insect gut. We first demonstrated that the luminal surface of the midgut and the basal surface of the salivary gland cells of the natural vector Scaphoideus titanus and those of the experimental vector Euscelidius variegatus were differentially glycosylated. Using ELISA, inhibition and competitive adhesion assays, and protein overlay assays in the Euva-6 insect cell line, we showed that the protein VmpA binds insect proteins in a lectin-like manner. In conclusion, the results of this study indicate that N-acetylglucosamine and mannose present on the surfaces of the midgut and salivary glands serve as recognition sites for the phytoplasma adhesin VmpA.
黄化植原体通过首先与昆虫细胞表面相互作用，主要在中肠腔和随后的唾液腺中，在其昆虫载体中经历增殖循环。黄化植原体与昆虫细胞的黏附由黏附素 VmpA 介导。我们假设 VmpA 可能具有凝集素样活性，类似于几种入侵昆虫肠道的细菌黏附素。我们首先证明了自然载体 Scaphoideus titanus 和实验载体 Euscelidius variegatus 的中肠腔的腔表面和唾液腺细胞的基底表面在糖基化方面存在差异。通过 ELISA、抑制和竞争黏附测定以及在 Euva-6 昆虫细胞系中的蛋白覆盖测定，我们表明 VmpA 蛋白以凝集素样方式结合昆虫蛋白。总之，这项研究的结果表明，中肠和唾液腺表面上的 N-乙酰葡萄糖胺和甘露糖作为植原体黏附素 VmpA 的识别位点。
