COBRE: UNE MED CTR:P6 ROLE OF RECYCLING IN INTEGRIN-MEDIATED SIGNALING

本子项目是利用由NIH/NCRR资助的中心赠款提供的资源的众多研究子项目之一。子项目和研究者（PI）可能已经从另一个NIH来源获得了主要资金，因此可以在其他CRISP条目中表示。列出的机构是中心的，不一定是研究者的机构。整合素是真核细胞粘附于细胞外基质（ECM）的主要受体。通过配体结合，整合素聚集到细胞骨架连接的局灶黏附复合物上，在癌细胞中发挥重要作用，影响肿瘤的信号转导、基因表达、增殖、凋亡调控、侵袭转移、血管生成和新生血管。为了传递信号，整合素必须定位于质膜并能够重新定位到病灶粘附处。虽然它们的内部化已被广泛研究，但很少有研究涉及整合素回收的调节。我们的长期目标是确定内源性运输对通过细胞粘附分子介导的信号转导的影响。由于异常的信号转导是癌症的主要原因，内吞运输的失调可能对局灶黏附完整性和肿瘤形成有重要影响。中心假设是，循环是β - 1整合素定位到局灶黏附的关键，也是整合素介导的细胞信号传导事件的关键。我们将首先确定β 1-整合素回收的程度，通过破坏回收和分析β 1-整合素在质膜上的水平。接下来，我们将使用RNAi来研究蛋白质参与调节β 1整合素循环。最后，我们将评估受损循环对整合素介导的信号传导和局灶粘附功能的影响，分析局灶粘附和细胞运动的底物磷酸化。我们的预期是：(1)再循环影响整合素在细胞内的行程；(2)整合素的再循环受EHD1、rabensyn -5、syntaxin 13和rabb家族蛋白的调控；(3)再循环受损会对整合素和其他蛋白在局点粘附的定位产生负面影响，影响正常的信号转导、细胞增殖和运动。这些结果将对癌症产生重要影响，因为清楚地了解通过局灶黏附控制信号的因素对于开发损害异常细胞生长的工具至关重要。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Integrins are the major eukaryote receptors for cell adhesion to the extracellular matrix(ECM). Upon ligand binding, integrins cluster to cytoskeleton-linked focal adhesion complexes and play significant roles in cancer cells, affecting signal transduction, gene expression, proliferation, apoptosis regulation, invasion, metastasis, and angiogenesis as well as neovascularization of tumors. To transmit signals, integrins must localize to the plasma membrane and be able to relocate to focal adhesions. While their internalization has been studied extensively, few studies have addressed the regulation of integrin recycling. Our long term goal is to determine the impact of endoctic trafficking on signal transduction mediated through cell adhesion molecules. Since aberrant signal transduction is a prime cause of cancer, dysregulation of endocytic trafficking may have an important bearing on focal adhesion integrity and tumor formation. The central hypothesis is that recycling is key to beta 1-integrin localization to focal adhesions and critical for integrin-mediated cellular signaling events. We will first determine the extent to which beta 1-integrins recycle, by impairing recycling and analyzing levels of beta 1-integrins on the plasma membrane. Next, we will use RNAi to study involvement of proteins in regulating beta 1-integrin recycling. Finally, we will assess the impact of impaired recycling on integrin-mediated signaling and focal adhesion function, analyzing the phospohorylation of substrates localized to focal adhesions and cell motility. Our expectations are: (1) recycling affects the intracellular itinerary of integrins (2) recycling of integrins is regulated by EHD1, Rabenosyn-5, syntaxin 13 and Rab-family proteins (3) impaired recycling will negatively affect localization of integrins and other proteins to focal adhesions, affecting normal siganl tranduction, cell proliferation and motility. These outcomes will have important ramifications for cancer, since a clear understanding of the elements controlling signaling via focal adhesions is essential for development of tools to impair aberrant cell growth.