Three new collagen VI genes; COL6A4, COL6A5 and COL6A6

三个新的 VI 型胶原蛋白基因；

基本信息

批准号：
8476984
负责人：
Jamie Fitzgerald
金额：
$ 28.16万
依托单位：
OREGON HEALTH & SCIENCE UNIVERSITY
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：
2009-07-30 至 2014-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8476984
关键词：
3q23 Address Affect Anabolism Basement membrane Bethlem Myopathy Biochemical C-terminal COL6A1 COL6A2 COL6A3 Candidate Disease Gene Cells Childhood Chromosomal Breaks Clinical Collagen Type VI DAG/PE-Binding Domain Development Discrimination Disease Elements Extracellular Matrix Family Fibroblasts Frameshift Mutation Gene Mutation Genes Genetic Counseling Genotype Goals Grant Health Human Human Chromosomes In Vitro Individual Knockout Mice Light Messenger RNA Microfibrils Modeling Molecular Mus Muscle Muscle Development Muscular Dystrophies Mutation Myopathy Names Nonsense Codon Patients Phenotype Proteins Recombinants Role Skeletal Muscle Staging Structure Testing Tissues Ullrich Congenital Muscular Dystrophy base congenital muscular dystrophy extracellular gene therapy in vivo member molecular assembly/self assembly mouse development neonate novel therapeutic intervention

项目摘要

DESCRIPTION (provided by applicant): Collagen VI is an extracellular matrix component that forms microfibrillar structures in virtually all tissues. To date, three collagen VI chains have been described; a1(VI), a2(VI) and a3(VI) which assemble in a 1:1:1 ratio. We have identified three additional collagen VI genes at a single locus on human chromosome 3q23 and named them COL6A4, COL6A5 and COL6A6 which encode the a4(VI), a5(VI) and a6(VI) chains, respectively. The COL6A4 gene is disrupted in humans and likely to be non-functional. Mutations in COL6A1, COL6A2 and COL6A3, result in two childhood muscle disorders; the relatively mild Bethlem myopathy (BM) and the more severe Ullrich congenital muscular dystrophy (UCMD). We identified a homozygous frameshift mutation in COL6A6 that results in a premature stop codon and is predicted to result in the complete absence of a6(VI) protein. The affected individual died as a neonate of a muscular dystrophy-like disorder that is more severe than BM or UCMD. We hypothesize that the a6(VI) chain is essential for development. Further, we hypothesize that the COL6A6 gene harbors mutations in individuals with severe congential muscular dystrophy distinct from BM and UCMD. The discovery of three additional collagen VI chains indicates that collagen VI assembly and extracellular microfibril composition is more complicated than previously thought. We hypothesize that the three new chains can substitute for a3(VI) to co-assemble with the a1(VI) and a2(VI) chains to form new molecular assemblies of collagen VI. The Specific Aims are: 1) To identify and characterize COL6A6 mutations in patients with congenital muscular dystrophy. Following identification of mutations, the biochemical consequences on collagen VI assembly and extracellular secretion will then be assessed in vitro in patient fibroblasts. 2) To analyze the function of the a6(VI) chain in vivo. We will generate a line of col6a6-null mice to serve as a model for the human mutation we identified. The effect of the lack of a6(VI) chains on mouse development will be examined in biochemical, immunohistochemical and ultrastructural analyses. 3) To understand the mechanism of a4(VI), a5(VI) and a6(VI) assembly into collagen VI. The potential for the new chains to co-assemble with a1 and a2 to form collagen VI heterotrimers will be assessed in vitro. Then, individual domains will be deleted systematically, and the effect on collagen VI biosynthesis, intracellular assembly and secretion determined. Our finding that the loss of a6(VI) protein leads is lethal in humans extends the severe end of the collagen VI disease spectrum and demonstrates that the a6(VI) chain is essential for normal development. This grant will explore the developmental and pathophysiological role of a6(VI) through the analysis of patient cells and of mice deficient for the col6a6 gene. In addition, we will define the mechanism of assembly of the new chain and explore whether they can form heterogeneous collagen VI structures.

描述（由申请人提供）：胶原蛋白VI是一种细胞外基质组件，几乎在所有组织中形成微纤维结构。迄今为止，已经描述了三个胶原蛋白链。 A1（VI），A2（VI）和A3（VI），以1：1：1的比例组装。我们已经在人类3q23上的单个基因座上确定了三个额外的胶原蛋白VI基因，并将其命名为Col6a4，Col6a5和Col6a6，分别编码A4（VI），A5（VI）和A6（VI）和A6（VI）链。 COL6A4基因在人类中被破坏，可能是非功能。 COL6A1，COL6A2和COL6A3的突变导致两个童年的肌肉疾病。伯特勒肌病（BM）和较严重的ullrich先天性肌肉营养不良（UCMD）。我们确定了COL6A6中的纯合移封突变，该突变导致过早的终止密码子，并预测会导致完全没有A6（VI）蛋白质。受影响的个体死于比BM或UCMD更严重的肌肉营养不良疾病的新生儿。我们假设A6（VI）链对于开发至关重要。此外，我们假设COL6A6基因具有与BM和UCMD不同的严重聚集肌营养不良症患者的突变。发现另外三个胶原蛋白链的发现表明，胶原蛋白VI组件和细胞外微纤维组成比以前想象的要复杂。我们假设这三个新链可以代替A3（VI）与A1（VI）和A2（VI）链共组装以形成胶原蛋白VI的新分子组件。具体目的是：1）识别和表征先天性肌营养不良症患者的COL6A6突变。鉴定突变后，将在患者成纤维细胞中评估胶原VI组装和细胞外分泌的生化后果。 2）分析体内A6（VI）链的功能。我们将生成一系列Col6a6-null小鼠，以作为我们确定的人类突变的模型。缺乏A6（VI）链对小鼠发育的影响将在生化，免疫组织化学和超微结构分析中进行检查。 3）了解A4（VI），A5（VI）和A6（VI）组装的机理中的机制。新链与A1和A2共组装形成胶原蛋白VI杂体三聚体的潜力将在体外评估。然后，将系统地删除各个结构域，并确定对胶原蛋白VI生物合成，细胞内组装和分泌的影响。我们的发现，在人类中，A6（VI）蛋白铅的损失是致命的，它扩展了胶原VI疾病谱的严重末端，并证明A6（VI）链对于正常发育至关重要。该赠款将通过分析患者细胞和缺乏COL6A6基因的小鼠来探讨A6（VI）的发育和病理生理作用。此外，我们将定义新链组装的机理，并探索它们是否可以形成异质性胶原蛋白VI结构。

项目成果

期刊论文数量（10）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

INPPL1 gene mutations in opsismodysplasia.

DOI：
10.1038/jhg.2016.119
发表时间：
2017-02
期刊：
Journal of human genetics
影响因子：
3.5
作者：
Fradet A;Fitzgerald J
通讯作者：
Fitzgerald J

Authentication of collagen VI antibodies.

VI 型胶原蛋白抗体的鉴定。

DOI：
10.1186/s13104-017-2674-x
发表时间：
2017
期刊：
BMC research notes
影响因子：
1.8
作者：
Endicott,Jamie;Holden,Paul;Fitzgerald,Jamie
通讯作者：
Fitzgerald,Jamie

Novel compound heterozygous mutations in inositol polyphosphate phosphatase-like 1 in a family with severe opsismodysplasia.

DOI：
10.1097/mcd.0000000000000136
发表时间：
2016-10
期刊：
Clinical dysmorphology
影响因子：
0.7
作者：
Feist C;Holden P;Fitzgerald J
通讯作者：
Fitzgerald J

The expanded collagen VI family: new chains and new questions.

DOI：
10.3109/03008207.2013.822865
发表时间：
2013
期刊：
Connective tissue research
影响因子：
2.9
作者：
Fitzgerald J;Holden P;Hansen U
通讯作者：
Hansen U

PHENOTYPIC VARIABILITY IN INDIVIDUALS WITH TYPE V OSTEOGENESIS IMPERFECTA WITH IDENTICAL IFITM5 MUTATIONS.

具有相同 IFITM5 突变的 V 型成骨不完美个体的表型变异。

DOI：
发表时间：
2013
期刊：
The Journal of rare disorders
影响因子：
0
作者：
Fitzgerald,Jamie;Holden,Paul;Wright,Hollis;Wilmot,Beth;Hata,Abigail;Steiner,RobertD;Basel,Don
通讯作者：
Basel,Don