Antimicrobial Activities of Cysteine-rich Peptides Specific to Bacteriocytes of the Pea Aphid Acyrthosiphon pisum
Antimicrobial Activities of Cysteine-rich Peptides Specific to Bacteriocytes of the Pea Aphid Acyrthosiphon pisum
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DOI：
10.1264/jsme2.me18148
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发表时间：
2019-03
影响因子：
2.2
通讯作者：
Nahoko Uchi;Mitsutaka Fukudome;N. Nozaki;Miyuzu Suzuki;Ken-ichi Osuki;S. Shigenobu;T. Uchiumi
中科院分区：
文献类型：
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作者：
Nahoko Uchi;Mitsutaka Fukudome;N. Nozaki;Miyuzu Suzuki;Ken-ichi Osuki;S. Shigenobu;T. Uchiumi
蚜虫与细菌内共生菌Buchnera aphidicola具有互惠共生关系。我们先前报道了豌豆蚜Acyrthosiphon pisum中的7个富含半胱氨酸的多肽，并将它们命名为细菌细胞特异性富含半胱氨酸的多肽(BCR)；这些多肽仅在细菌细胞中表达，这些细胞是特殊的含有共生体的蚜虫细胞。豆科植物根瘤中发现的类似的共生器官特异性富含半胱氨酸多肽称为富含半胱氨酸多肽(NCR)。NCR多肽以根瘤中的根瘤菌为靶标，是共生固氮所必需的。中华根瘤菌BACA(膜蛋白)突变体对NCR多肽敏感，不能建立共生关系。根据BCR多肽和NCR多肽在结构和表达上的相似性，我们推测蚜虫BCR多肽具有类似于某些NCR多肽的抗菌活性。我们合成了BCR多肽，并研究了它们的抗菌活性及其对大肠杆菌细菌膜的影响。多肽BCR1、BCR3、BCR5和BCR8具有抗菌活性，膜通透性增加。与紫花苜蓿BacA同源的大肠杆菌SBMA突变体对BCR多肽的敏感性高于野生型。我们的结果表明，BCR多肽具有控制内共生菌所需的特性，类似于豆类中的NCR多肽。
Aphids have a mutualistic relationship with the bacterial endosymbiont Buchnera aphidicola. We previously reported seven cysteine-rich peptides in the pea aphid Acyrthosiphon pisum and named them Bacteriocyte-specific Cysteine-Rich (BCR) peptides; these peptides are exclusively expressed in bacteriocytes, special aphid cells that harbor symbionts. Similar symbiotic organ-specific cysteine-rich peptides identified in the root nodules of leguminous plants are named Nodule-specific Cysteine-Rich (NCR) peptides. NCR peptides target rhizobia in the nodules and are essential for symbiotic nitrogen fixation. A BacA (membrane protein) mutant of Sinorhizobium is sensitive to NCR peptides and is unable to establish symbiosis. Based on the structural and expressional similarities between BCR peptides and NCR peptides, we hypothesized that aphid BCR peptides exhibit antimicrobial activity, similar to some NCR peptides. We herein synthesized BCR peptides and investigated their antimicrobial activities and effects on the bacterial membrane of Escherichia coli. The peptides BCR1, BCR3, BCR5, and BCR8 exhibited antimicrobial activities with increased membrane permeability. An sbmA mutant of E. coli, a homolog of bacA of S. meliloti, was more sensitive to BCR peptides than the wild type. Our results suggest that BCR peptides have properties that may be required to control the endosymbiont, similar to NCR peptides in legumes.