Chávez O, Harricane M C, Alemán V, Dorbani L, Larroque C, Mornet D, Rendon A, Martínez-Rojas D
Department of Physiology, Biophysics and Neuroscience, CINVESTAV-IPN, Av. 1PN2508, Colonia San Pedro Zacatenco, A.p. 14-740, México, D.F, 07360, México.
Biochem Biophys Res Commun. 2000 Aug 2;274(2):275-80. doi: 10.1006/bbrc.2000.3118.
In the brain, Dp71 is the most abundant protein product of the DMD gene and by alternative splicing of exon 78 two isoforms can be expressed, Dp71d and Dp71f. To explore the subcellular distribution of these Dp71 isoforms, specific monoclonal antibodies were used. Dp71d (with exon 78) was found in microsomes, while Dp71f (without exon 78) was detected in mitochondria. To determine the alterations which the absence of dystrophin proteins induces, we compared the expression of Dp71d in microsomes and Dp71f in mitochondria from mdx and mdx(3CV) mice. Dp71d in microsomes of mdx was similar to that of wild-type mice and, as expected, in mdx(3CV) this protein was undetectable. However, in mitochondria from mdx(3CV), Dp71f was overexpressed in comparison to mitochondria from mdx mice. Because in mdx(3CV) mice all the dystrophin proteins are mutated or diminished, we concluded that the protein detected in mitochondria is not a Dp71f but a novel product named Dp71f-like protein.
在大脑中，Dp71是DMD基因最丰富的蛋白质产物，通过外显子78的可变剪接可表达两种异构体，即Dp71d和Dp71f。为了探究这些Dp71异构体的亚细胞分布，使用了特异性单克隆抗体。发现Dp71d（含有外显子78）存在于微粒体中，而Dp71f（不含外显子78）在线粒体中被检测到。为了确定肌营养不良蛋白缺失所诱导的变化，我们比较了mdx和mdx(3CV)小鼠微粒体中Dp71d和线粒体中Dp71f的表达情况。mdx小鼠微粒体中的Dp71d与野生型小鼠相似，正如预期的那样，在mdx(3CV)小鼠中无法检测到这种蛋白质。然而，与mdx小鼠的线粒体相比，mdx(3CV)小鼠线粒体中的Dp71f过表达。由于在mdx(3CV)小鼠中所有的肌营养不良蛋白都发生了突变或减少，我们得出结论，在线粒体中检测到的蛋白质不是Dp71f，而是一种名为Dp71f样蛋白的新产物。
