Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The clinical progression of Duchenne muscular dystrophy (DMD) patients with deletions can be predicted in 93% of cases by whether the deletion maintains or disrupts the translational reading frame (frameshift hypothesis). We have identified and studied a number of patients who have deletions that do not conform to the translational frame hypothesis. The most common exception to the frameshift hypothesis is the deletion of exons 3 to 7 which disrupts the translational reading frame. We identified a Becker muscular dystrophy (BMD) patient, an intermediate, and a DMD patient with this deletion. In all three cases, dystrophin was detected and localized to the membrane. One DMD patient with an inframe deletion of exons 4-18 produced no dystrophin. One patient with a mild intermediate phenotype and a deletion of exon 45, which shifts the reading frame, produced no dystrophin. Two patients with large inframe deletions had discordant phenotypes (exons 3-41, DMD; exons 13-48, BMD), but both produced dystrophin that localized to the sarcolemma. The DMD patient, 113, indicates that dystrophin with an intact carboxy terminus can be produced in Duchenne patients at levels equivalent to some Beckers. The dystrophin analysis from these patients, together with patients reported in the literature, indicate that more than one domain can localize dystrophin to the sarcolemma. Lastly, the data shows that although most patients show correlation of clinical severity to molecular data, there are rare patients which do not conform.
Hum Mol Genet 1993 Jun
PMID:Characterization of translational frame exception patients in Duchenne/Becker muscular dystrophy. 835 93

The severe Duchenne muscular dystrophy (DMD) and the more benign Becker type (BMD) are allelic conditions, controlled by a defective gene at Xp21, caused by the absence (DMD) or a defect in quantity or quality (BMD) of the protein dystrophin. It has been suggested that the C-terminus domain of dystrophin is fundamental to ensure the proper protein sub-cellular localization and function. We wish to report our dystrophin findings in 4 among 142 DMD patients studied for DNA deletions and dystrophin analysis. Although they have a severe clinical course, a positive dystrophin immunofluorescence pattern was seen using C-terminal antibody, and a dystrophin band of reduced molecular weight (corresponding to their DNA deletions), but which maintained the C-terminus was seen through Western blot (WB). Based on these findings, we suggest that in order to partially maintain its function, resulting in a milder phenotype, dystrophin may carry large internal deletions but in addition to the C-terminus, the region encompassing both the N-terminus and the proximal region of the rod domain cannot be absent. Therefore, the prognosis of a Becker phenotype in a young patient should be done with caution if based only on the presence or not of dystrophin.
Hum Mol Genet 1993 Jan
PMID:Is the maintainance of the C-terminus domain of dystrophin enough to ensure a milder Becker muscular dystrophy phenotype? 849 Jun 21

The molecular defect in Duchenne muscular dystrophy is well established as being due to mutations at Xp21 which disrupt the normal synthesis of the 14kb dystrophin mRNA. More recently, several groups have identified a 4.8kb transcript from this locus which shares exons with the carboxy-terminal region of the dystrophin gene. In this paper we present evidence for an additional 2.2kb mRNA transcript. The 5' untranslated region and first 7 amino acids are identical to that published for the 4.8kb transcript. The position of the translational stop codon and 3' untranslated region is similar to that previously described as the truncated fetal dystrophin isoform. This 2.2kb mRNA has a similar tissue distribution to that described for the 4.8kb mRNA but unlike the other transcripts from the DMD locus, the 2.2kb mRNA is expressed in early development. The relevance of this transcript in the clinical expression of muscular dystrophy and developmental delay is discussed.
Hum Mol Genet 1993 May
PMID:Apo-dystrophin-3: a 2.2kb transcript from the DMD locus encoding the dystrophin glycoprotein binding site. 851 89

Dp71, a C-terminal isoform of dystrophin, has been identified as the major DMD gene product in many nonmuscle tissues. In this report, reverse transcriptase-polymerase chain reaction (RT-PCR) was used to clone and characterize four alternatively spliced Dp71 transcripts from cultured human amniocytes. The cDNAs encoding these Dp71 transcripts were shown to be alternatively spliced for exons 71 and/or 78. RT-PCR analysis also revealed that Dp71 transcripts alternatively spliced for exons 71 and/or 78 were expressed at varying levels in a number of adult human tissues, including muscle, heart, brain, kidney, lung, testis and liver. To investigate size heterogeneity at the translational level, Dp71 cDNAs isolated from amniocytes were expressed in E.coli to generate recombinant Dp71 fusion proteins. These fusion proteins were identified on immunoblots using antibodies specific for the C-terminal sequences of dystrophin that either included (antibody 1461) or excluded exon 78 (antibody 462B). The molecular masses of the Dp71 fusion proteins ranged from 71-75 kDa on SDS-PAGE, consistent with their predicted values. Immunoblot analysis using antibodies 1461 and 462B identified multiple Dp71 isoforms of approximately 70-75 kDa on SDS-PAGE in total protein lysates from amniocytes and various adult human tissues. This variation in molecular mass is consistent with the expression of Dp71 isoforms derived from transcripts alternatively spliced for exons 71 and/or 78. Total protein lysates from normal skeletal muscle, DMD muscle, amniocytes and brain were shown to contain beta-dystroglycan, a component of the dystrophin-associated glycoprotein complex (DGC).(ABSTRACT TRUNCATED AT 250 WORDS)
Hum Mol Genet 1995 Sep
PMID:Cloning and characterization of alternatively spliced isoforms of Dp71. 854 29

Dystrophin-associated proteins (DAPs) are classified into a few groups, namely, those comprising of dystroglycan complex, sarcoglycan complex, syntrophin complex and others. Subsarcolemmal actin filaments are connected to laminin in the basement membrane through dystrophin and the dystroglycan complex. This system may function to protect muscle fibers from mechanical damage. Furthermore, the sarcoglycan complex is associated with the system. Defects in the components of the protection system or the sarcoglycan complex or both are characteristically found in various muscular dystrophies. The roles of the syntrophin complex are meagerly understood. In this review, the possible roles of laminin, DAPs and dystrophin in each dystrophy are explained.
Hum Mol Genet 1995
PMID:Dystrophin-associated proteins in muscular dystrophy. 854 69

Dystrophin is the 427-kDa protein product of the Duchenne muscular dystrophy gene (DMD). The function of this protein remains to be elucidated. We have recently reported that dystrophin is phosphorylated, in vivo, in rat skeletal muscle primary cell culture (RE Milner, JL Busaan, CFB Holmes, JH Wang, M Michalak (1993) J Biol Chem 268:21901-21905). This observation suggests that protein phosphorylation may have some role in modulating the function of dystrophin or its interaction with membrane associate dystroglycan. We report here that the carboxyl-terminal of dystrophin is phosphorylated by the MAP kinase p44mpk (mitogen-activated protein kinase), from the sea star oocytes and by soluble extracts of rabbit skeletal muscle. Importantly we showed that native dystrophin in isolated sarcolemmal vesicles is phosphorylated by sea star p44mpk Partial purification and immunological analysis show that a mammalian kinase related to p44mpk is present in the skeletal muscle extracts and that it contributes to phosphorylation of the carboxyl-terminal of dystrophin. This kinase phosphorylates dystrophin on a threonine residue(s). We conclude that phosphorylation of dystrophin may play an important role in the function of this cytoskeletal protein.
Mol Cell Biochem 1995 Nov 08
PMID:Phosphorylation of the carboxyl terminal region of dystrophin by mitogen-activated protein (MAP) kinase. 860 12

Duchenne/Becker muscular dystrophy (DMD/BMD) is a severe X-linked myopathy. In 65% of the patients, the mutations responsible for the disease are macrodeletions in the dystrophin-encoding gene that can be identified with multiplex polymerase chain reaction (PCR) technology. We developed a method for quantitative PCR analysis of deletion carriers involving the use of phosphorimager-based scanning of radioactive-labelled PCR products. We calculated the ratios between the areas of two peaks, one corresponding to the deleted segments to be analysed and the other taken as a reference. In carriers, these ratios (R value) were always about half those obtained in normal females. The final diagnostic result, the diagnostic index (DI), is the ratio of the R values between the propositus and a normal subject. We also assessed the variability of each step of the procedure and the overall variability of the DI value, thus obtaining cut-off values that completely discriminated BMD/DMD deletion carriers from normal females. We were also able to classify, as either 'carrier' or 'normal', several females whose status was not identified with linkage analysis.
Mol Cell Probes 1996 Apr
PMID:A quantitative polymerase chain reaction (PCR) assay completely discriminates between Duchenne and Becker muscular dystrophy deletion carriers and normal females. 873 97

X-linked dilated cardiomyopathy (XLDC) is a familial heart disease presenting in young males as a rapidly progressive congestive heart failure, without clinical signs of skeletal myopathy. This condition has recently been linked to the dystrophin gene in some families and deletions encompassing the genomic region coding for the first muscle exon have been detected. In order to identify the defect responsible for this disease at the molecular level and to understand the reasons for the selective heart involvement, a family with a severe form of XLDC was studied. In the affected members, no deletions of the dystrophin gene were observed. Analysis of the muscle promoter, first exon and intron regions revealed the presence of a single point mutation at the first exon-intron boundary, inactivating the universally conserved 5' splice site consensus sequence of the first intron. This mutation introduced a new restriction site for MseI, which cosegregates with the disease in the analyzed family. Expression of the major dystrophin mRNA isoforms (from the muscle-, brain- and Purkinje cell-promoters) was completely abolished in the myocardium, while the brain- and Purkinje cell- (but not the muscle-) isoforms were detectable in the skeletal muscle. Immunocytochemical studies with anti-dystrophin antibodies showed that the protein was reduced in quantity but normally distributed in the skeletal muscle, while it was undetectable in the cardiac muscle. These findings indicate that expression of the muscle dystrophin isoform is critical for myocardial function and suggest that selective heart involvement in dystrophin-linked dilated cardiomyopathy is related to the absence, in the heart, of a compensatory expression of dystrophin from alternative promoters.
Hum Mol Genet 1996 Jan
PMID:A point mutation in the 5' splice site of the dystrophin gene first intron responsible for X-linked dilated cardiomyopathy. 878 42

In order to characterize the nature of mutations occurring in non-deleted Duchenne (DMD) and Becker muscular dystrophy (BMD) affected males, a total of 40 unrelated Italian patients was studied for the presence of point mutations within the muscle-specific regulatory region of the dystrophin gene. We decided to investigate the dystrophin promoter sequences because nucleotide variations in these regions could impair the expression of the gene and be the underlying molecular defect in some forms of the disease. In four patients suffering from mental retardation, the brain promoter region was also studied. To screen for point mutations, we applied molecular analysis by parallel denaturing gradient gel electrophoresis (DGGE). No sequence alterations were found in either the muscle or the brain promoters, suggesting that mutations in these regions do not represent a common mechanism of mutation in DMD/BMD.
Mol Cell Probes 1995 Dec
PMID:Mutational analysis of muscle and brain specific promoter regions of dystrophin gene in DMD/BMD Italian patients by denaturing gradient gel electrophoresis (DGGE). 880 15

Adenovirus-mediated gene transfer to muscle is a promising technology for gene therapy of Duchenne muscular dystrophy (DMD). However, currently available recombinant adenovirus vectors have several limitations, including a limited cloning capacity of approximately 8.5 kb, and the induction of a host immune response that leads to transient gene expression of 3-4 weeks in immunocompetent animals. Gene therapy for DMD could benefit from the development of adenoviral vectors with an increased cloning capacity to accommodate a full-length (approximately 14 kb) dystrophin cDNA. This increased capacity should also accommodate gene regulatory elements to achieve expression of transduced genes in a tissue-specific manner. Additional vector modifications that eliminate adenoviral genes, expression of which is associated with development of a host immune response, might greatly increase long-term expression of virally delivered genes in vivo. We have constructed encapsidated adenovirus minichromosomes theoretically capable of delivering up to 35 kb of non-viral exogenous DNA. These minichromosomes are derived from bacterial plasmids containing two fused inverted adenovirus origins of replication embedded in a circular genome, the adenovirus packaging signals, a beta-galactosidase reporter gene and a full-length dystrophin cDNA regulated by a muscle-specific enhancer/promoter. The encapsidated minichromosomes are propagated in vitro by trans-complementation with a replication-defective (E1 + E3 deleted) helper virus. We show that the minichromosomes can be propagated to high titer (> 10(8)/ml) and purified on CsCl gradients due to their buoyancy difference relative to helper virus. These vectors are able to transduce myogenic cell cultures and express dystrophin in myotubes. These results suggest that encapsidated adenovirus minichromosomes may be useful for gene transfer to muscle and other tissues.
Hum Mol Genet 1996 Jul
PMID:Encapsidated adenovirus minichromosomes allow delivery and expression of a 14 kb dystrophin cDNA to muscle cells. 881 25


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>