MOLECULAR PHYSIOLOGY OF BAND 3 LIKE PROTEINS OF KIDNEY

肾带 3 样蛋白的分子生理学

• 批准号: 6176522
• 负责人: SETH Leo ALPER
• 金额: $ 28.3万
• 依托单位: BETH ISRAEL DEACONESS MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-01-15 至 2003-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6176522
• 关键词: Xenopus oocyte; acidity /alkalinity; band 3 protein; bicarbonates; fatty acylation; gene mutation; genetic regulation; glycosylation; intracellular transport; ion transport; kidney cell; kidney function; laboratory mouse; membrane transport proteins; molecular cloning; protein isoforms; protein structure function; renal tubular transport; site directed mutagenesis; sulfates; tissue /cell culture; transfection

DESCRIPTION (Adapted from the Applicant's Abstract): The AE anion exchanger gene family encodes complex polytopic transmembrane polypeptides that contribute to regulation of intracellular pH (pHi), cell [Cl-], and cell volume through their mediation of electroneutral Cl-/HCO3- exchange. AE-mediated Cl-/HCO3- exchange in polarized epithelia also regulates secretion and reabsorption of proton equivalents and of Cl-. AE-mediated Cl-/HCO3-exchange is thought to be of widespread physiological importance in many cell types. AE1 deficiencies have been particularly associated with hereditary syndromes of spherocytic anemia and of distal renal tubular acidosis. Deficiencies of AE2 or AE3 activity have yet to be defined. Deficiency of a different Cl-/HCO3- exchange activity leads to congenital chloride diarrhea. This competitive continuation grant application proposes to extend past and current experiments by pursuit of the following Specific Aims: 1. Further define structural loci of the regulatory differences among AE isoforms, especially AE1 and AE2. 2. Study natural variants of the AE genes and a different class of anion exchanger for clues about ion translocation pathways and mechanisms. These will include: a. AE1 mutations that cosegregate and likely contribute to heritable distal renal tubular acidosis b. AE polypeptides of genetically related fish that live in river or in soda lake environments c. a more distantly related member of the bicarbonate-transporter superfamily cloned from yeast d. the unrelated sulfate transporter DRA that when mutated results in congenital chloride diarrhea. 3. Further compare and define the mechanisms of electroneutral and electrogenic anion exchange mediated by AE1 E699Q and likely mediated by AE2 E1007Q. 4. Apply directed mutagenesis to define the residues of AE1 and AE2 that contribute to binding and transport of substrate anions and to deduce constraints on secondary and tertiary structure of AE polypeptides. 5. Define aspects of transcriptional and translational regulation of AE gene products in kidney of mutant and parental mouse strains and in cultured kidney cells.

描述（改编自申请人的摘要）：AE阴离子交换剂 基因家族编码复杂的多面体跨膜多肽 有助于调节细胞内 pH (pHi)、细胞 [Cl-] 和细胞 通过介导电中性 Cl-/HCO3- 交换来调节体积。 AE 介导的极化上皮细胞中的 Cl-/HCO3- 交换也调节 质子当量和 Cl- 的分泌和重吸收。 AE介导的 Cl-/HCO3-交换被认为具有广泛的生理重要性 许多细胞类型。 AE1 缺陷与以下因素特别相关： 球形红细胞性贫血和远端肾小管遗传性综合征 酸中毒。 AE2 或 AE3 活性的缺陷尚未确定。 不同的 Cl-/HCO3- 交换活性的缺乏会导致先天性 氯化物腹泻。 这项竞争性的延续拨款申请提出 通过追求以下具体内容来扩展过去和当前的实验 目标： 1. 进一步明确AE之间调控差异的结构位点 同工型，尤其是 AE1 和 AE2。 2. 研究 AE 基因的自然变体和不同类别的阴离子 交换器以获取有关离子易位途径和机制的线索。 这些 将包括： 一个。 AE1 突变共分离并可能导致遗传 远端 肾小管性酸中毒 b.生活在河流或水中的遗传相关鱼类的 AE 多肽 苏打湖环境 c.碳酸氢根转运蛋白中关系较远的成员 从酵母中克隆的超家族 d.不相关的硫酸盐转运蛋白 DRA 突变时会导致 先天性氯化物腹泻。 3. 进一步比较和定义电中性和电中性的机理 由 AE1 E699Q 介导的生电阴离子交换，可能由 AE2 介导 E1007Q。 4. 应用定向诱变来定义 AE1 和 AE2 的残基， 有助于底物阴离子的结合和运输并推断 AE多肽二级和三级结构的限制。 5. 定义 AE 转录和翻译调控的各个方面 突变体和亲代小鼠肾中以及培养物中的基因产物 肾细胞。