Investigating Molecular Assembly and Dynamics of Tick Cement proteins

摘要 壁虱必须用它们有刺的口器(腹口)深深地刺入宿主的真皮 (皮肤)，然后将龟头包在水泥锥体中，以保持坚固、疼痛和瘙痒- 自由附着，随后将传染病病原体传播到受害者体内。两种类型 在扁虱身上发现了大量的水泥；早期的水泥在几分钟后就会分泌出来 附着并迅速硬化，附着后24小时分泌的晚期粘固剂 并逐渐变硬。这些分泌的水泥锥由几个 富含甘氨酸的蛋白质(GRP)是一个由多种蛋白质组成的大家族，以其 粘附性和拉伸特性。这些特性可能在宿主皮肤中发挥重要作用 在长时间内获得不间断的血液供应的依恋。我们的长- 在地区资助申请中的学期计划是揭示细胞的功能和生化特性 新型GRP在水泥锥体组装、隐形附着、吞血(供血)和 气候适应。我们将检验我们的中心假设，即生化和生物力学 GRP的属性有助于未检测到的对主机的连接，从而提供对 作为水泥锥体器械的脚手架，不间断地提供血液。我们的 多学科团队将使用人工膜喂养的组合来验证这一假说， 结构、蛋白质组学和反向遗传学方法。具体目标是：1)确定 独特的唾液GRP在骨水泥锥体组装和安全附着体中的作用 人工膜投加系统，以及2)定义未表征的生物化学特性 重组表达的骨水泥锥体蛋白。靶向扁虱水泥蛋白可能提供一种 创新的方式为扁虱的依附创造敌意的情况，并最终中断 把扁虱传播的病原体接种到寄主体内。了解水泥的作用机理 使扁虱能够稳定地、隐形地附着的组件将提供对 开发新的控制和预防方法。

Summary Ticks must use their barbed mouthparts (hypostome) to pierce deeply into the host’s dermis (skin), then encase the hypostome in a cement cone in order to maintain a firm, pain and itch- free attachment, subsequently transmitting infectious disease agents into the victim. Two types of cement have been found in ticks; early cement which is secreted only minutes after attachment and hardens rapidly, and late cement which is secreted 24 hours after attachment to the host and hardens gradually. These secreted cement cones are composed of several glycine-rich proteins (GRPs) which are a large family of diverse proteins that are known for their adhesive and tensile characteristics. Such properties may play an important role in host skin attachment to gain an uninterrupted supply of blood over a prolonged period of time. Our long- term plan in the AREA grant application is to reveal the functions and biochemical properties of novel GRPs in cement cone assembly, stealth attachment, hematophagy (blood feeding) and climatic adaptation. We will test our central hypothesis that biochemical and biomechanical properties of GRPs assist in the undetected attachment to the host, providing access to an uninterrupted supply of blood by serving as scaffolding for the cement cone apparatus. Our multidisciplinary team will test the hypothesis using a combination of artificial membrane feeding, structural, proteomics, and reverse genetics approaches. Specific aims are to: 1) determine the role of unique salivary GRPs in cement cone assembly and secure attachment by using an artificial membrane feeding system, and 2) define the biochemical properties of uncharacterized recombinantly expressed cement cone proteins. Targeting tick cement proteins may provide an innovative way to create a hostile situation for tick attachment, and ultimately interrupt the inoculation of tick-borne pathogens into the host. Understanding the mechanisms of cement assembly that allow the tick to secure a stable, stealthy attachment will provide insight into developing new control and prevention methods.