Cytoskeletal Membrane Anchors: Key Switchboards for Cellular Communication, Mecha

细胞骨架膜锚：细胞通信、机甲的关键交换机

• 批准号: 8265194
• 负责人: Volkmar Heinrich
• 金额: $ 26.02万
• 依托单位: UNIVERSITY OF CALIFORNIA AT DAVIS
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-09-01 至 2016-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8265194
• 关键词: Actins; Adhesives; Affinity; Behavior; Binding; Biochemical; Biochemistry; Biomedical Engineering; Cadherins; Calcium; Cell Communication; Cell Surface Receptors; Cell membrane; Cell physiology; Cell surface; Cells; Cellular biology; Chemicals; Chemistry; Collaborations; Communication; Complex; Custom; Cytoplasmic Tail; Cytoskeleton; Defect; Diagnosis; Disease; Dissociation; Docking; Drug usage; Elements; Event; Extracellular Domain; Failure; Fluorescence; Fluorescent Probes; Foundations; Functional Imaging; Future; Generic Drugs; Homing; Immune; Individual; Inflammation; Inflammatory; Integrins; Leukocytes; Life; Ligands; Link; Malignant Neoplasms; Measurement; Measures; Mechanical Stimulation; Mechanical Stress; Mechanics; Mediating; Membrane; Molecular; Molecular Biology; N-Cadherin; Nanotubes; Nature; Neoplasm Metastasis; P-selectin ligand protein; Physiologic pulse; Physiological; Play; Process; Proteins; Reaction; Regulation; Reporter; Research; Role; Rupture; Scheme; Side; Signal Transduction; Site; Spectrum Analysis; Staging; Stimulus; Stress; Structure-Activity Relationship; Techniques; Testing; Time; Translating; Work; adapter protein; base; cancer cell; cantilever; cell motility; experience; extracellular; fighting; genetic manipulation; innovation; insight; instrument; interest; laser tweezer; leukocyte activation; mechanical behavior; migration; nano; neutrophil; novel; physical property; receptor; receptor binding; research study; response; single molecule; tool

DESCRIPTION (provided by applicant): A cell's communication with its surroundings is central to numerous physiological functions in both normal and diseased states. It requires that encounters with extracellular ligands can be "sensed" inside the cell, and conversely, that the strength of extracellular ligand-receptor interactions can be modulated by intracellular processes. Adapter proteins that link the cytoplasmic domains of cell-surface receptors to the cytoskeleton ("cytoskeletal membrane anchors") are likely to play a crucial biophysical role in this bidirectional communication, i.e., not only as cell-signaling messengers, but also as structural elements that mediate, and possibly regulate, a cell's response to mechanical stimuli. Accordingly, this application puts forward the paradigm that serial linkages of the form extracellular ligand - transmembrane receptor - cytoskeletal anchor - cortical actin represent functional units that act as key biophysical switchboards in cellular communication. Often such serial linkages are exposed to physical stress, in which case the strength hierarchy of individual molecular interactions, along with the physical properties of the plasma membrane and the actin cortex, provide the mechanistic foundation of their mechanoregulatory behavior. Understanding these complex mechanisms requires an interdisciplinary, nano-to-microscale approach. We propose to systematically dissect the individual contributions of the constituents of two types of serial transmembrane linkages. Aims 1 and 2 will establish the structural behavior of serial linkages involving the integrin LFA-1 and E- and N-cadherins. Aim 1 will focus on extracellular binding by quantifying the dynamics of formation and force-dependent failure of the respective receptor:ligand bonds (using cutting-edge force- probe instruments, i.e., our side-view AFM and optical tweezers). Aim 2 will examine the mechanical behavior and the molecular determinants of the cytoskeletal anchors of these receptors. Combining force probing and fluorescent functional imaging, Aim 3 will investigate how this structural organization correlates with cellula function. For example, we will explore the mechanisms of leukocyte activation by mechano-chemical stimuli. This strategy will open new avenues toward establishing a biologically plausible and physically realistic understanding of these remarkable mechanosignaling paths, and thus also toward novel bottom-up strategies for diagnosis and treatment of diseases. PUBLIC HEALTH RELEVANCE: Although vital processes like the migration of immune cells to sites of inflammation, or the migration, homing, and invasion of cancer cells during metastasis, rely heavily on the regulation of the cells' ability to hold on to each other at one stage and let o at another, it remains poorly understood how a cell, at the "opportune" moment, "instructs" the extracellular domains of its docking molecules to "let go". Likewise, little is known about how a cell "translates" external mechanical stimuli into well-defined cytoplasmic responses. This application posits that cytoskeletal membrane anchors are key switchboards in force-sensitive cellular communication. Using innovative biophysical concepts and tools, this project will elucidate mechanoregulatory processes that are inaccessible to existing techniques, and thus provide new insight for future bottom-up strategies to fight cancer, immune defects, and other diseases.

描述（由申请人提供）：在正常和患病状态下，细胞与周围环境的交流是许多生理功能的核心。它要求与细胞外配体的接触可以在细胞内“感知”，相反，细胞外配体-受体相互作用的强度可以通过细胞内过程调节。连接细胞表面受体的细胞质结构域和细胞骨架（“细胞骨架膜锚”）的衔接蛋白可能在这种双向通信中发挥重要的生物物理作用，即，不仅作为细胞信号信使，而且作为介导和可能调节细胞对机械刺激反应的结构元件。因此，该应用提出了细胞外配体-跨膜受体-细胞骨架锚点-皮质肌动蛋白的序列连接形式，代表了细胞通信中充当关键生物物理交换机的功能单位。通常，这些序列连接暴露在物理应力下，在这种情况下，单个分子相互作用的强度等级，以及质膜和肌动蛋白皮层的物理性质，为它们的机械调节行为提供了机制基础。理解这些复杂的机制需要跨学科的、纳米到微观尺度的方法。我们建议系统地剖析两种类型的串联跨膜连接的成分的个人贡献。目的1和2将建立涉及整合素LFA-1和E-和n -钙粘蛋白的串联连接的结构行为。目标1将通过量化各自受体：配体键的形成和力依赖失败的动力学来关注细胞外结合（使用尖端的力探测仪器，即我们的侧视图AFM和光学镊子）。目的2将检查这些受体的细胞骨架锚的机械行为和分子决定因素。结合力探测和荧光功能成像，Aim 3将研究这种结构组织如何与细胞功能相关。例如，我们将探索由机械化学刺激激活白细胞的机制。这一策略将为建立对这些显著的机械信号通路的生物学上合理和物理上现实的理解开辟新的途径，从而也为疾病的诊断和治疗开辟新的自下而上的策略。