Molecular cloning of Aralar, a new member of the mitochondrial carrier superfamily that binds calcium and is present in human muscle and brain
Molecular cloning of Aralar, a new member of the mitochondrial carrier superfamily that binds calcium and is present in human muscle and brain
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DOI：
10.1074/jbc.273.36.23327
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发表时间：
1998-09-04
影响因子：
4.8
通讯作者：
Satrústegui, J
中科院分区：
文献类型：
--
作者：
del Arco, A;Satrústegui, J
我们已经鉴定了一个新的钙依赖性线粒体载体蛋白亚家族，其成员来自酿酒酵母、秀丽隐杆线虫和各种哺乳动物物种。该亚家族的成员具有二分结构：具有线粒体溶质载体超家族特征的羧基末端一半和含有各种 EF 手结构域的氨基末端延伸。该亚科的一个成员（我们称之为 Aralar）是从人类心脏 cDNA 文库中克隆出来的。相应的cDNA包含2037个碱基对的开放阅读框，编码678个氨基酸的多肽。 Aralar 的羧基端一半（氨基酸 321-678）与氧化戊二酸、柠檬酸和腺嘌呤核苷酸载体（28-29% 同一性）具有高度相似性，而氨基端一半（氨基酸 1-320）包含三个典型的 EF 手。通过 Ca-45(2+) 叠加和钙依赖性迁移率变化测定，显示 Aralar 氨基末端一半可结合钙。在用 Aralar 转染的 COS 细胞中，该蛋白的亚细胞定位完全是线粒体。针对 Aralar 氨基末端融合蛋白的抗体可识别脑线粒体组分中的 70 kDa 蛋白。 Northern印迹分析表明该蛋白在心脏、大脑和骨骼肌中表达。结构域结构、线粒体定位以及在可兴奋组织中的存在表明 Aralar 可能具有作为钙依赖性线粒体溶质载体的功能。
We have identified a new calcium-dependent subfamily of mitochondrial carrier proteins with members in Saccharomyces cerevisiae, Caenorhabditis elegans, and various mammalian species. The members of this subfamily have a bipartite structure: a carboxyl-terminal half with the characteristic features of the mitochondrial solute carrier superfamily and an amino-terminal extension harboring various EF-hand domains. A member of this subfamily (that we have termed Aralar) was cloned from a human heart cDNA library. The corresponding cDNA comprises an open reading frame of 2037 base pairs encoding a polypeptide of 678 amino acids. The carboxyl-terminal half of Aralar (amino acids 321-678) has high similarity with the oxoglutarate, citrate, and adenine nucleotide carriers (28-29% identity), whereas the amino-terminal half (amino acids 1-320) contains three canonical EF-hands. Aralar amino-terminal half was shown to bind calcium by Ca-45(2+) overlay and calcium-dependent mobility shift assays. The sub cellular localization of the protein in COS cells transfected with Aralar was exclusively mitochondrial. Antibodies against Aralar amino-terminal fusion protein recognized a 70-kDa protein in brain mitochondrial fractions. Northern blot analysis showed that the protein was expressed in heart, brain, and skeletal muscle. The domain structure, mitochondrial localization, and presence in excitable tissues suggests a possible function of Aralar as calcium-dependent mitochondrial solute carrier.