Shokeen Bhumika, Park Jane, Duong Emily, Rambhia Sonam, Paul Manash, Weinberg Aaron, Shi Wenyuan, Lux Renate
Section of Periodontics, Division of Constitutive & Regenerative Sciences, UCLA School of Dentistry, Los Angeles, CA 90095, USA.
David Geffen School of Medicine, UCLA, Los Angeles, CA 90095, USA.
Microorganisms. 2020 Jan 2;8(1):70. doi: 10.3390/microorganisms8010070.
RadD, a major adhesin of oral fusobacteria, is part of a four-gene operon encoding the small lipoprotein FAD-I and two currently uncharacterized small proteins encoded by the and genes. Previously, we described a role for FAD-I in the induction of human B-defensin 2 (hBD2) upon contact with oral epithelial cells. Here, we investigated potential roles for , and in interspecies interaction and biofilm formation. Gene inactivation mutants were generated for each of these genes in the and subspecies of and characterized for their adherence to partner species, biofilm formation, and operon transcription. Binding to was increased in all mutant strains with Δ having the most significant effect. This increased adherence was directly proportional to elevated transcript levels and resulted in significantly different architecture and height of the biofilms formed by Δ and compared to the wild-type parent. In conclusion, FAD-I is important for fusobacterial interspecies interaction as its lack leads to increased production of the RadD adhesin suggesting a role of FAD-I in its regulation. This regulatory effect does not require the presence of functional RadD.
RadD是口腔梭杆菌的一种主要黏附素，它是一个四基因操纵子的一部分，该操纵子编码小脂蛋白FAD-I以及由 和 基因编码的另外两种目前尚未明确特征的小蛋白。此前，我们描述了FAD-I在与口腔上皮细胞接触时诱导人β-防御素2（hBD2）产生方面的作用。在此，我们研究了 、 和 在种间相互作用和生物膜形成中的潜在作用。在 的 和 亚种中针对这些基因分别构建了基因失活突变体，并对它们与伙伴物种的黏附、生物膜形成及操纵子转录进行了表征。所有突变菌株与 的结合均增加，其中Δ 的影响最为显著。这种增加的黏附与 转录水平升高成正比，并且与野生型亲本相比，由Δ 和 形成的生物膜在结构和高度上存在显著差异。总之，FAD-I对梭杆菌种间相互作用很重要，因为其缺失会导致RadD黏附素产生增加，这表明FAD-I在其调控中发挥作用。这种调节作用不需要功能性RadD的存在。
