Mechanisms of Integrin Receptor Transmembrane Signaling

项目摘要/摘要 我们的长期研究兴趣在于努力了解细胞表面受体的结构基础 跨膜信号和细胞内蛋白质之间的信息传递。 特别关注的是细胞黏附受体的整合素家族，这是 脊椎动物的功能，对血管系统的运行至关重要。 整合素由两个非共价结合的亚基组成，称为α和β，并具有 在细胞膜上双向传输信号的非凡能力。要做到这一点，单曲 其两个亚基的跨膜螺旋必须编码至少三种功能状态(无效， 由内而外和由外而内的信号)。然而，除了认识到分离 跨膜螺旋伴随着跨膜信号，很少有数据，特别是结构数据， 可用于跨膜螺旋堆积、倾斜和膜包埋。为了努力发现 细胞骨架蛋白talin与整合素β结合后的激活信号 胞浆尾巴是通过细胞膜传递的，我们的研究追求以下具体目标： (I)单体的结构、动力学和膜包埋的测定 整合素βIIB和β3亚基的跨膜螺旋。(Ii)阐明结构、相互作用 异二聚体整合素？IIB和？3跨膜螺旋的膜包埋。(Iii) 评估Talin与？3和？IIB-？3跨膜结构结合的后果， 相互作用和膜包埋。我们正在使用溶液核磁共振波谱来完成这些 目标。产生包含整合素？IIB-？3跨膜和胞浆尾巴的多肽 重组，并在脂质双层模型膜中重组。整合素？IIB-？3介导 因此，血小板聚集是血栓形成的关键调节因素。为了有效地控制和，如果 适用，预防血栓，其病理表现导致心脏病发作和中风， 导致它们形成的分子事件必须被理解。因此，我们的研究有助于 了解血管系统内分子和细胞的相互作用，将有助于 开发治疗血管疾病的药物和疗法。项目叙事 中风和心脏病发作是导致死亡的两个主要原因，它们是由脑血管病变引起的 血管系统。目前的提议为理解一个关键的调解人提供了结构性基础 印迹血小板聚集，将有助于通过药物控制这一过程。

PROJECT SUMMARY/ABSTRACT Our long-term research interest lies in striving to understand the structural basis of cell surface receptor transmembrane signaling and the concomitant relay of information to and from intracellular proteins. Particular focus is placed on the integrin family of cell-adhesion receptors, which is indispensable for the functioning of vertebrates and is of central importance to the operation of the vascular system. Integrins consist of two non-covalently associated subunits, termed alpha and beta, and possess the remarkable ability to transmit signals bidirectionally across the cell membrane. To do so, the single transmembrane helices of their two subunits must encode at least three functional states (inactive, inside-out and outside-in signaling). However, aside from recognizing that a separation of the transmembrane helices accompanies transmembrane signaling, little data, in particular structural data, is available about transmembrane helix packing, tilt and membrane embedding. In an effort to discover how an activating signal, following the binding of the cytoskeletal protein talin to the integrin beta cytosolic tail, is transmitted across the cell membrane, our research pursues the following specific aims: (i) Determination of the structure, dynamics and membrane embedding of the monomeric transmembrane helix of each integrin ?IIb and ?3 subunit. (ii) Elucidation of the structure, interaction and membrane embedding of the heterodimeric integrin ?IIb and ?3 transmembrane helices. (iii) Evaluation of the consequences of talin binding to the ?3 and ?IIb-?3 transmembrane structure, interaction and membrane embedding. We are using solution NMR spectroscopy to accomplish these goals. Peptides encompassing the integrin ?IIb-?3 transmembrane and cytosolic tails are produced recombinantly and they are reconstituted in lipid bilayer model membranes. Integrin ?IIb-?3 mediates blood platelet aggregation and, as such, is a key regulator of thrombosis. To effectively control and, if applicable, prevent thrombi, whose pathological appearances lead to heart attack and stroke, the molecular events leading to their formation must be understood. Thus, our research contributes to the understanding of the interactions of molecules and cells within the vascular system, and will aid in the development of drugs and therapies to treat vascular diseases. PROJECT NARRATIVE Stroke and heart attack, two of the major causes of death, arise from pathological aberrations of the vascular system. The current proposal provides the structural basis for understanding a key mediator of blot platelet aggregation and will aid in providing control of this process by drugs.