Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0026850 (muscular dystrophy)
 5,870 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Plectin, a member of the cytolinkers protein family, plays a crucial role in cells as a stabilizing element of cells against mechanical stress. Its absence results in muscular dystrophy, skin blistering, and signs of neuropathy. The C-terminal domain of plectin contains several highly homologous repeat domains that also occur in other cytolinkers. Secondary structure analysis revealed that the building block of these domains, the PLEC repeat, is similar to the ankyrin repeat. We present a model that attempts to explain how the C-terminal domain, which comprises approximately 1900 amino acid, could be stabilized to maintain its structural integrity even under extensive mechanical stress. In this model, larger solenoid modules formed from PLEC repeats can be disulfide-bridged via conserved cysteines. Our hypothesis suggests that this process could be mediated by cytoplasmic NOS-generated products, such as the radical peroxynitrite. Reinforcement of molecular structure would provide a rationale why during exercising or physical stress radicals are formed without necessarily being deleterious. This article contains supplementary material that may be viewed at the BioEssays website at http://www.interscience.wiley.com/jpages/0265-9247/suppmat/23/v23_11.1064.html.
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PMID:Plectin repeats and modules: strategic cysteines and their presumed impact on cytolinker functions. 1174 22

Cardiac ankyrin-repeated protein (CARP) has been shown to associate with a transcription factor, YB-1, that may activate expression of the ventricular myosin light chain-2 gene during cardiogenesis. CARP is induced in the adult hypertrophic heart subjected to pressure overload, suggesting that CARP may play important functional roles in both embryonic and adult hearts. Although CARP expression was initially believed to be restricted to the heart, we found recently that CARP is induced strongly in human fetal skeletal muscle and in experimentally denervated skeletal muscle, leading us to speculate that CARP may also play important roles in skeletal muscle. In the present study, we found that in rats initially damaged by a single injection of bupivacaine, CARP expression was induced strongly in regenerating muscles with a peak 3 days after the injection, followed by down-regulation to undetectable levels after 28 days. Although CARP was coexpressed with embryonic myosin heavy chain (MHC) in regenerating myofibers, CARP expression persisted even after down-regulation of embryonic MHC expression, whereas it began to decrease before the onset of slow or fast MHC expression, suggesting that CARP is expressed at a specific differentiation stage during muscle regeneration. We analyzed the expression of CARP in muscle biopsy specimens from 14 patients with muscular dystrophy (MD) and detected high expression of CARP in 13 of the 14 cases. CARP-positive myofibers were detected more often in congenital muscular dystrophy (CMD) than in Duchenne muscular dystrophy (DMD). We found that CARP was expressed exclusively, and at a high level, in small regenerating myofibers that express embryonic MHC in DMD, which suggested that CARP could be used as a marker of muscle regeneration in DMD. On the other hand, in CMD, expression of CARP was not limited to regenerating fibers, being detectable in myofibers expressing embryonic MHC and those expressing mature-type MHC. These findings suggest that the differentiation stage of CARP-positive myofibers in DMD and CMD may differ.
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PMID:Cardiac-restricted ankyrin-repeated protein is differentially induced in duchenne and congenital muscular dystrophy. 1274 80

Cardiac ankyrin-repeated protein (CARP) was originally identified as a protein specifically expressed in cardiomyocytes, but has recently been found to be upregulated in some muscle diseases including muscular dystrophy and myopathy, suggesting that CARP may be induced in some pathologic conditions. In this study, we immunohistochemically analyzed 69 renal biopsy samples from patients with glomerular diseases and 2 individuals with normal kidney. We found that CARP was expressed in renal podocytes at a high level in 10 of 13 cases of crescentic glomerulonephritis, 7 of 19 cases of diabetic nephropathy, and 12 of 20 cases of lupus nephritis, although it was not expressed in endocapillary glomerulonephritis, minimal change disease, thin basement membrane disease, membranous glomerulonephritis, and normal kidney. Interestingly, in lupus nephritis, CARP expression tended to be induced in cases exhibiting nephrotic syndrome, but less so in cases without nephrotic syndrome, suggesting that CARP expression is correlated with the severity of proteinuria. Furthermore, we found that CARP was not expressed in membranous glomerulonephritis but evidently expressed in most cases of membranous lupus nephritis. Although membranous glomerulonephritis and membranous lupus nephritis are sometimes morphologically indistinguishable, it is suggested that their pathologic mechanisms differ. Therefore, we propose that examination of CARP expression is useful for precise differential diagnosis of membranous glomerulonephritis and membranous lupus nephritis.
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PMID:Upregulated expression of cardiac ankyrin-repeated protein in renal podocytes is associated with proteinuria severity in lupus nephritis. 1723 33

p94/calpain 3 is a skeletal muscle-specific Ca(2+)-regulated cysteine protease (calpain), and genetic loss of p94 protease activity causes muscular dystrophy (calpainopathy). In addition, a small in-frame deletion in the N2A region of connectin/titin that impairs p94-connectin interaction causes a severe muscular dystrophy (mdm) in mice. Since p94 via its interaction with the N2A and M-line regions of connectin becomes part of the connectin filament system that serves as a molecular scaffold for the myofibril, it has been proposed that structural and functional integrity of the p94-connectin complex is essential for health and maintenance of myocytes. In this study, we have surveyed the interactions made by p94 and connectin N2A inside COS7 cells. This revealed that p94 binds to connectin at multiple sites, including newly identified loci in the N2A and PEVK regions of connectin. Functionally, p94-N2A interactions suppress p94 autolysis and protected connectin from proteolysis. The connectin N2A region also contains a binding site for the muscle ankyrin repeat proteins (MARPs), a protein family involved in the cellular stress responses. MARP2/Ankrd2 competed with p94 for binding to connectin and was also proteolyzed by p94. Intriguingly, a connectin N2A fragment with the mdm deletion possessed enhanced resistance to proteases, including p94, and its interaction with MARPs was weakened. Our data support a model in which MARP2-p94 signaling converges within the N2A connectin segment and the mdm deletion disrupts their coordination. These results also implicate the dynamic nature of connectin molecule as a regulatory scaffold of p94 functions.
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PMID:Multiple molecular interactions implicate the connectin/titin N2A region as a modulating scaffold for p94/calpain 3 activity in skeletal muscle. 1831 72