Betal Integrin and Renal Tubulogenesis

β整合素和肾小管发生

• 批准号: 8668041
• 负责人: ROY ZENT
• 金额: $ 33.93万
• 依托单位: VANDERBILT UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-03-04 至 2016-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8668041
• 关键词: Adhesions; Adult; Affect; Binding; Binding Sites; Biochemical; Biological; Biological Assay; Biology; Case Study; Cells; Cytoplasmic Tail; Data; Defect; Development; Distal; Duct (organ) structure; Dysplasia; Epithelial; Etiology; Exhibits; Extracellular Matrix; Funding; Goals; In Vitro; Infant; Integrins; Kidney; Kidney Diseases; Kidney Failure; Knockout Mice; Knowledge; Ligand Binding; Mammals; Manuscripts; Mass Spectrum Analysis; Mediating; Membrane; Metanephric Diverticulum; Morphogenesis; Mus; Mutate; Mutation; Nephrons; Phenotype; Preparation; Process; Property; Protein Binding; Protein Binding Domain; Proteins; Renal tubule structure; Research; Role; Signal Transduction; Syndrome; System; Tail; Talin; Techniques; Testing; Transgenic Mice; dimer; in vivo; insight; migration; mouse development; mouse model; nephrogenesis; novel; programs; receptor; skin disorder

DESCRIPTION (provided by applicant): Integrins, the principal receptors that mediate cell-ECM interactions, are composed of heterodimeric transmembrane and subunits. The 18 and 8 subunits found in mammals combine in a restricted manner to form specific dimers with different ligand binding properties. 1, the most abundantly expressed integrin subunit in the kidney, binds at least 12 subunits. Its short cytoplasmic tail interacts with multiple intracellular molecules tht promote integrin- mediated adhesion, migration and signaling. The best defined of these proteins are talins and kindlins, which we and others showed are required for normal integrin function. These proteins bind to two canonical NPXY motifs found in all integrin cytoplasmic tails: talins to the membrane proximal and kindlins to the membrane distal motifs. In the last funding period, we utilized integrin beta1flox/flox mice to demonstrate that this integrin subunit s required for normal uretereic bud (UB) development, as deleting it using hoxb7cre mice resulted in severe abnormalities in branching morphogenesis. We further showed that mutating canonical NPXY motifs of the integrin 1 cytoplasmic tail also resulted in abnormal UB development. Kidneys with a Y/A mutation in both motifs (thus affecting binding of talins and kindlins) are severely dysmorphic and dysplastic, but have a significantly less severe branching defect than the UB integrin 1-null mice. Thus a key unanswered question in the field of integrin biology and kidney development is how the NPXY motifs regulate integrin function and whether they have distinct functions from each other. We propose to answer this question by testing the hypothesis that binding of talins and kindlins to specific NPYX motifs of the integrin 1 cytoplasmic tail differentially regulates integrin functions required for normal UB development. This hypothesis will be tested by the following three specific aims. 1) Determine if talin binding to the membrane proximal NPXY motif of the integrin 1 cytoplasmic tail is required for normal UB development. 2) Determine if kindlin binding to the membrane distal NPXY motif of the integrin 1 cytoplasmic tail is required for normal UB development and function. 3) Define the mechanisms whereby integrin 1 NPXY motif binding proteins regulate collecting duct cell branching morphogenesis. Completion of these aims will help define the fundamental mechanisms whereby 1 integrins regulate renal tubule formation in the context of UB development. This has implications for our understanding of both congenital renal hypoplasia/dysplasia syndromes and adult renal diseases as UB branching is a key determinant of nephron number.

描述（由申请人提供）：整合素，介导细胞ECM相互作用的主要受体由异二聚体跨膜和亚基组成。在哺乳动物中发现的18和8个亚基以限制的方式组合，形成具有不同配体结合特性的特定二聚体。 1是肾脏中最丰富的整联蛋白亚基，结合至少12个亚基。它的短细胞质尾巴与多个细胞内分子相互作用，促进整合素介导的粘附，迁移和信号传导。这些蛋白质的最佳定义是Talins和Kindlins，我们和其他蛋白质是正常整联蛋白功能所必需的。这些蛋白质与在所有整合素细胞质尾巴中发现的两个规范的NPXY基序结合：TALINS与膜近端和Kindlins与膜远端基序中。在最后的资金期间，我们利用整联蛋白beta1flox/flox小鼠证明了正常输尿管芽（UB）发育所需的整合素亚基S，因为使用HOXB7CRE小鼠删除了它，从而导致分支形成的严重异常。我们进一步表明，整联蛋白1细胞质尾部的突变典型的NPXY基序也导致UB发育异常。在两个基序中具有y/a突变的肾脏（因此影响塔林斯和亲戚的结合）都是严重的畸形和发育不良的肾脏，但与UB 1-NULL小鼠相比，分支缺陷的严重性明显少得多。因此，整合素生物学和肾脏发育领域中的一个关键未解决问题是NPXY基序如何调节整合素的功能以及它们是否彼此具有不同的功能。我们建议通过测试塔林斯和Kindlins与整联蛋白1细胞质尾的特定NPYX基序的假设来回答这个问题，从而差异地调节了正常UB发育所需的整合素函数。该假设将通过以下三个特定目标来检验。 1）确定整联蛋白蛋白的膜近端NPXY基序是否需要正常UB发育中的胞质尾巴。 2）确定kindlin是否与整合素的膜远端NPXY基序结合1胞质尾巴需要正常的UB发育和功能。 3）定义整合素1 NPXY基序结合蛋白调节收集管细胞分支形态发生的机制。这些目的的完成将有助于定义基本机制，从而在UB开发中调节肾小管形成1个基本机制。这对我们对先天性肾功能低下/发育不良综合征和成人肾脏疾病的理解具有影响，因为UB分支是肾脏数量的关键决定因素。