权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Molecular and Biochemical Studies on Compensatory Mechanisms for Total Band 3 Deficiency in Japanese Black Cattle

日本黑牛总带 3 缺陷补偿机制的分子和生化研究

基本信息

批准号：
09460145
负责人：
INABA Mutsumi
金额：
$ 7.87万
依托单位：
The University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1999
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09460145/
关键词：
Red cells Membrane proteins Band 3 Hereditary diseases Anion transport Acid-base balance Membrane skeleton Japanese black cattle

项目摘要

Band 3 has been believed to be essential to survival of mammals. The aim of this research project is to define compensatory mechanisms for total band 3 deficiency in cattle.1) Linkage analyses showed that the genotype for R664X mutation determined by PCR-RFLP coinherited with the red cell phenotype of dominantly inherited HS and band 3 deficiency, demonstrating that R664X mutation is the principal molecular cause for dominant hereditary band 3 deficiency in cattle associated with HS.2) Extensive studies on the red cell membrane proteins demonstrated that the major proximal causes for the membrane instability of homozygous and heterozygous cells appear to be the loss of band 3-ankyrin-spectrin association, and the reduction of spectrin, respectively. Quantitation of mutant mRNA co-injection of normal and mutant RNA into Xenopus oocytes, and in vitro synthesis/immunoprecipitation of normal and the mutant bend 3 demonstrated a dominant-negative effect of the mutant protein in vivo on the expression of normal band 3. A hypothetical possibility for pathogenesis of HS in the affected animals involves : (1) Band 3-independent assembly of membrane skeleton to the plasma membrane. (2) Translocation of reduced normal band 3-ankyrin and their association with spectrin to strengthen interactions between the lipid bilayer and the skeleton in heterozygous but not m homozygous red cells.3) Bovine red cells with total band 3 deficiency possessed anion transport activity mediated by AE2, with substrate specificity an sensitivity to stilbene disulfonate which were extremely lower than those in normal cells. T e rapid anion exchange was not compensated at all, indicating that the function of band 3 is not obligatory to 0ィイD22ィエD2/C0ィイD22ィエD2 exchange.

Band 3一直被认为是哺乳动物生存所必需的。1)连锁分析表明，R664X突变的基因型与显性遗传性HS和带状3缺乏的红细胞表型是共遗传的，证明R664X突变是牛显性遗传性带状3缺失的主要分子原因。2)对红细胞膜蛋白的广泛研究表明，纯合和杂合细胞膜不稳定性的主要近端原因似乎分别是带3-Ankyrin-Spectrin结合的丧失和Spectrin的减少。将正常和突变的RNA共同注射到非洲爪哇卵母细胞中，以及正常和突变的bend 3蛋白的体外合成/免疫沉淀的定量结果表明，突变的蛋白在体内对正常带3的表达具有显性-负性效应。HS发病机制的一个假设可能涉及：(1)膜骨架与质膜的带3独立组装。(2)在杂合子而不是纯合子红细胞中，还原的正常带3-Ankyrin的移位及其与血影蛋白的结合增强了脂双层与骨架之间的相互作用。3)总带3缺陷的牛红细胞具有AE2介导的阴离子转运活性，底物特异性对二苯乙烯二磺酸的敏感性极低。快速阴离子交换完全没有补偿，表明带3的功能不是0ィイD22ィエD2/C0ィイD22ィエD2交换所必需的。