A novel ADP/ATP transporter in the mitosome of the microaerophilic human parasite Entamoeba histolytica
A novel ADP/ATP transporter in the mitosome of the microaerophilic human parasite Entamoeba histolytica
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DOI：
10.1016/j.cub.2005.02.068
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发表时间：
2005-04-26
期刊：
影响因子：
9.2
通讯作者：
Tovar, J
中科院分区：
文献类型：
--
作者：
Chan, KW;Slotboom, DJ;Tovar, J
最近的数据表明，缺乏氧化磷酸化的微需氧和寄生原生动物含有线粒体同源物[1-6]，这些细胞器与线粒体具有共同的祖先。这种广泛的保留表明，线粒体同源物可能有一个共同的功能，使它们对真核细胞至关重要。我们确定了溶组织内阿米巴线粒体同源物的线粒体载体家族（MCF）补体，也称为密码子[5]或更常见的线粒体[3]。MCF蛋白通过将线粒体基质中的生化途径与细胞溶质中的生化途径连接起来，支持线粒体代谢能量产生、DNA复制和氨基酸代谢[7]。因此，MCF多样性密切反映了线粒体代谢多样性的重要方面。溶组织内阿米巴有丝分裂体已经失去了所有，但一种单一类型的MCF蛋白，通过一种新的机制，这是不依赖于膜电位的ATP和ADP的运输。系统发育分析证实，内阿米巴ADP/ATP载体不同于原型线粒体ADP/ATP载体，这一观察结果得到其不同底物和抑制剂特异性的支持。由于酵母和人类线粒体的许多功能依赖于由该家族的专门成员转运的溶质，因此内阿米巴线粒体必须仅包含需要腺嘌呤核苷酸交换的这些过程的一小部分。
Recent data suggest that microaerophilic and parasitic protozoa, which lack oxidative phosphorylation, nevertheless contain mitochondrial homologs [1-6], organelles that share common ancestry with mitochondria. Such widespread retention suggests there may be a common function for mitochondrial homologs that makes them essential for eukaryotic cells. We determined the mitochondrial carrier family (MCF) complement of the Entamoeba histolytica mitochondrial homolog, also known as a crypton [5] or more commonly as a mitosome [3]. MCF proteins support mitochondrial metabolic energy generation, DNA replication, and amino-acid metabolism by linking biochemical pathways in the mitochondrial matrix with those in the cytosol [7]. MCF diversity thus closely mirrors important facets of mitochondrial metabolic diversity. The Entamoeba histolytica mitosome has lost all but a single type of MCF protein, which transports ATP and ADP via a novel mechanism that is not reliant on a membrane potential. Phylogenetic analyses confirm that the Entamoeba ADP/ATP carrier is distinct from archetypal mitochondrial ADP/ATP carriers, an observation that is supported by its different substrate and inhibitor specificity. Because many functions of yeast and human mitochondria rely on solutes transported by specialized members of this family, the Entamoeba mitosome must contain only a small subset of these processes requiring adenine nucleotide exchange.