MOLECULAR MECHANISMS OF CELL SUBSTRATE INTERACTIONS

细胞基质相互作用的分子机制

• 批准号: 2572358
• 负责人: S K AKIYAMA
• 金额: --
• 依托单位: NATIONAL INSTITUTE OF DENTAL & CRANIOFACIAL RESEARCH
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/2572358
• 关键词: cell adhesion; cell growth regulation; cell migration; fibronectins; integrins; intermolecular interaction; molecular cloning; protein structure function; tissue /cell culture

Fibronectin and integrin receptors play important roles in such processes as embryonic development, wound healing, and the progression of cancer. Techniques involving monoclonal antibodies, molecular and cell biology, and biophysical chemistry are used to elucidate molecular mechanisms of fibronectin-receptor interactions with the long-term goals of producing novel bioadhesive substrates and developing rational bases for medical intervention in diseases involving abnormal cellular adhesion and migration. The central cell-binding region of fibronectin requires two distinct sequences for activity: an RGD sequence and a PHSRN synergistic sequence. Bacterially-expressed 20 kd cell adhesive fragments of fibronectin, consisting of the complete ninth and tenth type III modules containing the RGD and the PHSRN sequences, have been cloned and expressed. These fragments have been found to retain the full biological activity attributable to the central cell binding region of intact fibronectin when present in solution as an inhibitor of fibronectin function. The structure of the 20 kd murine fibronectin fragment is being analyzed using biophysical techniques. Although the ninth and tenth modules have been found to interact, the PHSRN and RGD sites are located at relatively distant sites that probably do not interact directly. The through-space distance of the PHSRN and RGD sites is small enough to be spanned by a single integrin receptor. Certain monoclonal antibodies that bind to beta1 integrins can up-regulate their ligand-binding activity. One such activating antibody, designated 12G10, appears to bind to a "ligand-induced" conformation. This antibody can also inhibit proliferation of cultured cells. This growth arrest occurs near the G1/S boundary of the cell cycle and is suggestive of a mechanism for integrin-mediated modulation of the cell cycle.

纤维连接蛋白和整合素受体在这一过程中起重要作用。 胚胎发育，伤口愈合， 癌症的进展。 涉及单克隆抗体的技术， 分子和细胞生物学以及生物物理化学被用来 阐明纤连蛋白-受体相互作用的分子机制 其长期目标是生产新型生物粘附基质， 为疾病的医疗干预建立合理的基础 涉及异常的细胞粘附和迁移。 中央 纤连蛋白的细胞结合区需要两个不同的序列 对于活性：RGD序列和PHSRN协同序列。 细菌表达的纤连蛋白的20 kd细胞粘附片段， 由完整的第九和第十类III模块组成 含有RGD和PHSRN序列的基因，已经被克隆， 表达。 这些碎片被发现保留了完整的 归因于中央细胞结合区的生物活性 当存在于溶液中时， 纤连蛋白功能。 20 kd鼠纤维连接蛋白的结构 正在使用生物物理技术分析碎片。 虽然 已经发现第九和第十模块相互作用，PHSRN 和RGD位点位于相对较远的位点， 不要直接互动。 PHSRN的穿越空间距离 和RGD位点小到足以被单个整合素跨越 受体的 某些与β 1整联蛋白结合的单克隆抗体 可以上调它们的配体结合活性。 一个这样的激活 命名为12 G10的抗体似乎与“配体诱导的” 构象 该抗体还可以抑制 培养细胞 这种生长停滞发生在G1/S边界附近， 细胞周期，并提示了整合素介导的细胞凋亡的机制。 调节细胞周期。