Structure/function analysis of the na/bicarbonate cotransporters

na/碳酸氢盐协同转运蛋白的结构/功能分析

基本信息

批准号：
8126250
负责人：
INYEONG CHOI
金额：
$ 26.24万
依托单位：
EMORY UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2007
资助国家：
美国
起止时间：
2007-07-01 至 2013-06-30
项目状态：
已结题

项目摘要

DESCRIPTION (provided by applicant): ABSTRACT One of the tasks of the kidney is to maintain cellular and total body acid-base homeostasis by reclaiming filtered bicarbonate and making and saving new bicarbonate. The electrogenic sodium/bicarbonate cotransporter (NBCe1) plays a significant role in reabsorbing bicarbonate in the proximal tubules, where more than 80% of filtered bicarbonates are reclaimed. Electrogenic function of NBCe1 is essential for this bicarbonate reabsorption, producing a driving force for sodium and bicarbonate exit across the basolateral membranes of the proximal tubule cells. Altered activities of NBCe cause severe proximal renal tubule acidosis as well as glaucoma and cataracts. The long-term goal of this project is to elucidate molecular mechanisms for electrogenic sodium/bicarbonate transport of NBCe1. We propose to perform an integrated structure/function analysis of NBCe1 and identify the structural domains and amino acid residues that are essential for electrogenicity. The experimental designs are i) to systematically construct a series of chimeric transporters from NBCe1 and the electroneutral sodium/bicarbonate transporter NBCn1 that moves sodium and bicarbonate into the cell, and ii) to construct point mutants of NBCe1 by sequence comparison with NBCn1. There are three specific aims. In Aim 1, we will identify the transmembrane domains of NBCe1 that affect electrogenicity. Chimeric transporters will be constructed by swapping individual transmembrane domains of NBCe1 with the homologous regions of NBCn1. The function of those chimeric transporters will be analyzed by measuring the pH recovery rate and bicarbonate-dependent currents in Xenopus oocytes expressing the proteins. In Aim 2, we will determine amino acid residues affecting electrogenicity. We will select the residues, within identified domains, that might severely alter electrogenic function and mutate them. In Aim 3, we will distinguish functionally essential transmembrane domains and amino acids from structurally supportive ones. This will be done by reconstituting identified domains/amino acids of NBCe1 into the electroneutral transporter. The proposed work will help develop molecular models of electrogenic sodium/bicarbonate movement via NBCe1

项目成果

期刊论文数量（9）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Cation-coupled bicarbonate transporters.

DOI：
10.1002/cphy.c130005
发表时间：
2014-10
期刊：
Comprehensive Physiology
影响因子：
5.8
作者：
Aalkjaer C;Boedtkjer E;Choi I;Lee S
通讯作者：
Lee S

SLC4A transporters.

DOI：
10.1016/b978-0-12-394316-3.00003-x
发表时间：
2012
期刊：
Current topics in membranes
影响因子：
0
作者：
Choi I
通讯作者：
Choi I

Sodium-bicarbonate cotransporter NBCn1/Slc4a7 inhibits NH4Cl-mediated inward current in Xenopus oocytes.

DOI：
10.1113/expphysiol.2011.057844
发表时间：
2011-08
期刊：
Experimental physiology
影响因子：
2.7
作者：
Lee S;Choi I
通讯作者：
Choi I

Inhibition of rat Na+(-)HCO3(-) cotransporter (NBCn1) function and expression by the alternative splice domain.

选择性剪接结构域对大鼠 Na (-)HCO3(-) 协同转运蛋白 (NBCn1) 功能和表达的抑制。

DOI：
10.1113/expphysiol.2009.048603
发表时间：
2009
期刊：
Experimental physiology
影响因子：
2.7
作者：
Yang,HanSoo;Cooper,DeborahS;Rajbhandari,Ira;Park,HaeJeong;Lee,Soojung;Choi,Inyeong
通讯作者：
Choi,Inyeong

Lack of Charge Interaction in the Ion Binding Site Determines Anion Selectivity in the Sodium Bicarbonate Cotransporter NBCe1.