Analysis of fibroblast proteins from patients with Duchenne muscular dystrophy by two-dimensional gel electrophoresis.

Duchenne muscular dystrophy (DMD), the most common and severe form of the muscular dystrophies, is an X-linked inborn error of metabolism with multiple tissue involvement. Although the major pathological changes are observed in skeletal muscle, abnormalities have also been detected in the heart, nervous system, red blood cells, lymphocytes and cultured skin fibroblasts. For many reasons, such as readily available tissue material, fewer secondary changes and the potential for prenatal diagnosis, cultured skin fibroblasts should be the tissue of choice to search for the primary defect. Several abnormalities have been reported in DMD fibroblasts, suggesting that the genetic abnormality is expressed in these cells. To search for potentially mutant protein(s) we have compared the protein composition of normal and DMD fibroblasts by two-dimensional gel electrophoresis and have now found one protein spot consistently missing in DMD cells. The nature of this protein and its relation to the DMD gene are unknown.     

应用cDNA检测RFLPs和核酸杂交剂量诊断DMD／BMD基因携带者的研究

用ｄｙｓｔｒｏｐｈｉｎｃＤＮＡ检出ＢｇｌⅡ和ＸｂａⅠＲＦＬＰｓ，结合ＤＮＡ杂交剂量分析法，检测了申请作了ＤＭＤ／ＢＭＤ杂合子鉴定的８个家系６９个人的基因型，通过８个ＲＦＬＰｓ的基因内连锁分析和基因剂量分析，１１名女性被诊断为ＤＭＤ基因突变携带者，４名女性为可能携带者，１２名女性被确认为正常个体，３名未到出现ＤＭＤ临床症状年龄的男孩被诊断为正常个体，此外，在４０名子代中发现２名女性有基因内重组，１名     

High-affinity binding site for a specific nuclear protein in the human IgM gene

Proteins binding to specific regions of DNA with high affinity frequently govern or regulate reactions at the gene level. We have identified a high-affinity binding site in the immunoglobulin mu gene that binds a specific nuclear protein, and have now characterized it fully using nuclear factor 1 (NF-1), a protein purified from the nuclei of HeLa cells and required for the in vitro replication of adenovirus (Ad) DNA. NF-1 protects a 25-base pair (bp) double-stranded segment of DNA which shares a consensus sequence, 5' TGGA/CNNNNNGCCAA 3', with similar binding sites in the Ad-5 terminal repeat and the human c-myc gene. Although this site differs from the enhancer region, a biological function is suggested by the fact that it is DNase I hypersensitive in immunoglobulin-producing lymphoblastoid cells. The binding site for the NF-1 protein in the mu gene, by analogy with the site in the Ad-5 terminal repeat, may represent one component of a cellular origin of replication; alternatively, it may be responsible for the activation of the chromatin in this region.