Larsson N G, Garman J D, Oldfors A, Barsh G S, Clayton D A
Department of Development Biology, Bechman Center for Molecular and Genetic Medicine, Stanford University School of Medicine, Calfornia 94305-5427, USA.
Nat Genet. 1996 Jul;13(3):296-302. doi: 10.1038/ng0796-296.
Mitochondrial transcription factor A (mtTFA) is a key regulator of mammalian mitochondrial DNA transcription. We report here that a testis-specific isoform of mouse mtTFA lacks the mitochondrial targeting sequence and is present in the nucleus of spermatocytes and elongating spermatids, thus representing the first reported mammalian gene encoding protein isoforms targeted for the mitochondria or the nucleus. The presence of the mitochondrial transcriptional activator in the nucleus raises the possibility of a role for this protein in both genetic systems. Mutations in the nuclear mtTFA gene may therefore exhibit phenotypic consequences due to altered function in either or both genetic compartments.
线粒体转录因子A（mtTFA）是哺乳动物线粒体DNA转录的关键调节因子。我们在此报告，小鼠mtTFA的一种睾丸特异性同工型缺乏线粒体靶向序列，存在于精母细胞和伸长型精子细胞的细胞核中，因此代表了首个被报道的编码靶向线粒体或细胞核的蛋白质同工型的哺乳动物基因。线粒体转录激活因子在细胞核中的存在增加了该蛋白在两个遗传系统中发挥作用的可能性。因此，核mtTFA基因中的突变可能由于在一个或两个遗传区室中的功能改变而表现出表型后果。
