Interactions between a luteovirus and the GroEL chaperonin protein of the symbiotic bacterium Buchnera aphidicola of aphids
Interactions between a luteovirus and the GroEL chaperonin protein of the symbiotic bacterium Buchnera aphidicola of aphids
复制标题
DOI：
10.1099/vir.0.029355-0
复制
发表时间：
2011-06-01
影响因子：
3.8
通讯作者：
Douglas, Angela E.
中科院分区：
文献类型：
--
作者：
Bouvaine, Sophie;Boonham, Neil;Douglas, Angela E.
luteovirus和polovirus是重要的植物病毒，仅由蚜虫通过蚜虫血淋巴循环传播。一种由蚜虫共生菌合成的伴侣蛋白GroEL被认为与血淋巴中的病毒颗粒结合，从而促进传播。为了验证这一假设，我们在体外确定了大麦黄矮病毒（BYDV）的GroEL结合位点，并研究了GroEL蛋白在不同蚜虫组织中的丰度。病毒与代表完整GroEL分子的肽库结合，发现了一个单一的结合位点，该位点与固定两个GroEL环形成天然GroEL四聚体的位点一致。在GroEL蛋白的功能形式中，病毒结合将与两个GroEL环的形成相竞争。使用针对Buchnera特异性GroEL表位的单抗，通过免疫印迹和免疫细胞化学在Buchnera细胞中检测到GroEL，但在蚜虫的血淋巴、脂肪体或肠道中未检测到GroEL。从GroEL病毒相互作用可能受到与其他GroEL分子的竞争的严重限制这一预测，以及GroEL病毒在体内不能与病毒颗粒相互作用的证据，可以得出结论，GroEL病毒相互作用不太可能促进蚜虫传播病毒。
Luteoviruses and poleroviruses are important plant viruses transmitted exclusively by aphids in a circulative manner via the aphid haemolymph. A chaperonin protein, GroEL, synthesized in aphids by a symbiotic bacterium, Buchnera aphidicola, is hypothesized to bind to virus particles in the haemolymph, thereby promoting transmission. To investigate this hypothesis, the GroEL-binding site for barley yellow dwarf virus (BYDV) was determined in vitro, and the abundance of GroEL protein in different aphid tissues was investigated. Virus binding to a peptide library representing the full GroEL molecule revealed a single binding site that coincides with the site that anchors two GroEL rings to form the native GroEL tetradecamer. In the functional form of the GroEL protein, virus binding would compete with the formation of the two GroEL rings. Using a mAb raised against a Buchnera-specific GroEL epitope, GroEL was detected in Buchnera cells by immunoblotting and immunocytochemistry, but not in the aphid haemolymph, fat body or gut. From the prediction here that GroEL virus interactions are probably severely limited by competition with other GroEL molecules, and the evidence that GroEL is not available to interact with virus particles in vivo, it is concluded that GroEL virus interactions are unlikely to contribute to virus transmission by aphids.