一种与带3抗原相关的45 kDa蛋白质在肾线粒体中选择性表达。

A 45-kDa protein antigenically related to band 3 is selectively expressed in kidney mitochondria.

作者信息

Ostedgaard L S, Jennings M L, Karniski L P, Schuster V L

机构信息

Department of Medicine, University of Iowa, Iowa City 52242.

出版信息

Proc Natl Acad Sci U S A. 1991 Feb 1;88(3):981-5. doi: 10.1073/pnas.88.3.981.

DOI:10.1073/pnas.88.3.981

PMID:1704136

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC50938/

Abstract

Anion exchange similar to that catalyzed by erythrocyte band 3 occurs across many nonerythroid cell membranes. To identify anion-exchange proteins structurally related to band 3, we immunoblotted rabbit kidney medullary membrane fractions with anti-band 3 antibodies. Immunoblots using antibodies to the cytoplasmic domain of band 3 revealed cross-reactive proteins in the plasma membrane fraction only. In contrast, two monoclonal antibodies against band 3 membrane domain labeled a 45-kDa protein; further immunoblotting and immunogold studies of membrane fractions and kidney sections using one of the anti-membrane domain antibodies showed that labeling was strongest in mitochondria of H(+)-secreting collecting duct cells. Tissue-to-tissue expression of the 45-kDa mitochondrial protein was variable: kidney medulla greater than heart greater than kidney cortex much greater than liver. We conclude that a 45-kDa protein with immunological cross-reactivity to the erythrocyte band 3 membrane domain is expressed in mitochondria in a highly cell-specific fashion and speculate that the protein may play a role in mitochondrial anion transport.

摘要

类似于红细胞带3催化的阴离子交换发生在许多非红细胞细胞膜上。为了鉴定与带3结构相关的阴离子交换蛋白，我们用抗带3抗体对兔肾髓质膜组分进行了免疫印迹分析。使用针对带3细胞质结构域的抗体进行的免疫印迹仅在质膜组分中显示出交叉反应蛋白。相比之下，两种针对带3膜结构域的单克隆抗体标记了一种45 kDa的蛋白；使用其中一种抗膜结构域抗体对膜组分和肾切片进行的进一步免疫印迹和免疫金研究表明，在分泌H⁺的集合管细胞的线粒体中标记最强。这种45 kDa线粒体蛋白在不同组织中的表达存在差异：肾髓质＞心脏＞肾皮质＞肝脏。我们得出结论，一种与红细胞带3膜结构域具有免疫交叉反应性的45 kDa蛋白以高度细胞特异性的方式在线粒体中表达，并推测该蛋白可能在线粒体阴离子转运中发挥作用。