Understanding transmembrane helix interaction on the structural level

在结构水平上理解跨膜螺旋相互作用

基本信息

批准号：
7886793
负责人：
Gevorg Grigoryan
金额：
$ 2.52万
依托单位：
UNIVERSITY OF PENNSYLVANIA
依托单位国家：
美国
项目类别：
财政年份：
2009
资助国家：
美国
起止时间：
2009-07-01 至 2010-12-31
项目状态：
已结题

项目摘要

DESCRIPTION (provided by applicant): Understanding how transmembrane (TM) helices recognize each other is an important and challenging problem. Here I propose to utilize the integrin system to study structural and sequence determinants of TM helix interaction preferences. Integrins are a family of dimeric single-pass membrane proteins that act as cell adhesion receptors. Integrins are known to exist in at least two states - an active state, where they bind extracellular ligands and an inactive state, where this binding does not occur. It has been shown that peptides that interfere-with the dimerization of integrin TM helices, by interacting with one of the monomers, cause integrin activation. The ability to consistently design such peptides de novo critically depends on our understanding of TM helix interaction preferences. Therefore, to study these preferences, I will establish a cycle between the computational design of such peptides and their experimental characterization. I will design: 1) peptides that disrupt the TM helix association of alpha2beta1 and alpha4beta1 by interacting with the alpha subunits and 2) peptides that stabilize the TM helix association of alphallbbetaS by forming a trimeric helix bundle with the native dimer. I will also make use of the fact that integrins are a diverse family (with 18 alpha and 8 beta subunits known in vertebrates) to study the problem of designing TM helix interaction specificity. Integrins are involved in many biologically critical processes and are associated with such human conditions as cancer angiogenesis and metastasis and various bleeding disorders. By deciphering the principles of integrin TM interaction specificity, this work will suggest ways to selectively activate or deactivate particular receptors, which can lead to novel therapies. Additionally, understanding the determinants of TM helix interactions in general will have a wider impact on dissecting transmembrane protein folding and interaction. PUBLIC HEALTH RELEVANCE: Integrins are a family of proteins that that are involved in a great variety of biological processes and human diseases, from immune response and leukocyte trafficking to cancer, development and blot clotting. Central to the function of integrins is the association between their transmembrane (TM) regions. This work will shed light on the principles by which TM regions recognize each other, which will provide a way of controlling integrin activity and will likely lead to novel therapies.

描述（由申请人提供）：了解跨膜（TM）螺旋如何相互认识是一个重要且具有挑战性的问题。在这里，我建议利用整合素系统研究TM螺旋相互作用偏好的结构和序列决定因素。整联蛋白是充当细胞粘附受体的二聚体单通膜蛋白的家族。已知整联蛋白至少存在于两个状态 - 一个活性状态，它们结合细胞外配体和一种不活跃的状态，在这种状态下不会发生这种结合。已经表明，通过与其中一个单体相互作用，会导致整联蛋白激活，从而干扰整联蛋白TM螺旋的二聚化的肽。始终如一地设计这种肽的能力在很大程度上取决于我们对TM螺旋相互作用偏好的理解。因此，为了研究这些偏好，我将在此类肽的计算设计及其实验表征之间建立一个周期。我将设计：1）通过与α2Beta1和alpha4beta1的TM螺旋相关的肽通过与α亚基相互作用以及2）肽通过与天然二聚体形成三聚螺旋束，从而稳定Alphallbbetas的TM螺旋结合的肽。我还将利用一个事实，即整联蛋白是一个多样的家族（脊椎动物中已知的18个α和8个β亚基）来研究设计TM螺旋相互作用特异性的问题。整联蛋白参与许多生物学关键过程，并与诸如癌症血管生成和转移以及各种出血疾病等人类状况有关。通过解释整联蛋白TM相互作用特异性的原理，这项工作将提出选择性激活或失效特定受体的方法，从而导致新的疗法。另外，了解一般的TM螺旋相互作用的决定因素将对剖析跨膜蛋白折叠和相互作用产生更广泛的影响。公共卫生相关性：整合素是一个蛋白质家族，涉及各种生物学过程和人类疾病，从免疫反应和白细胞贩运到癌症，发育和印迹凝结。整联蛋白功能的核心是其跨膜（TM）区域之间的关联。这项工作将阐明TM区域相互认识的原理，这将提供一种控制整合素活性的方法，并可能导致新的疗法。