scholarly journals The Genes, Proteins, and the Cell Biological Processes Underlying Emery-Dreifuss Muscular Dystrophy

2017 ◽  
Vol 6 (1) ◽  
pp. 14-18
Author(s):  
Elise Alexandra Kikis ◽  
Megan Elizabeth Mastey
Keyword(s):  
Muscular Dystrophy ◽  
Nuclear Envelope ◽  
Autosomal Dominant ◽  
Nuclear Lamina ◽  
Autosomal Recessive Inheritance ◽  
Envelope Proteins ◽  
Lamin A ◽  
Dominant Form ◽  
Specific Effects ◽  
Autosomal Dominant Form

Emery-Dreifuss Muscular Dystrophy (EDMD) is a type of muscular dystrophy characterized by contractures, or shortening of muscles or joints in the elbows and Achilles tendons, muscle wasting and weakness as well as cardiomyopathy. There are two main forms of inherited EDMD, X-linked recessive and autosomal dominant. There is also a rarer form of autosomal recessive inheritance with only a few cases ever reported. The X-linked form of EDMD is caused by mutation of the STA gene that encodes the protein emerin, while the autosomal dominant form is caused by a missense mutation on the LMNA gene, which encodes lamin A/C proteins. Both emerin and lamin A/C are nuclear envelope proteins that interact with other proteins to create a connective network that attaches the nuclear lamina to the cytoskeleton. These nuclear envelope proteins interact via accessory proteins to chromatin and also thereby stimulate gene expression. The exact mechanism of how mutations in these genes lead to muscular dystrophy is not well understood. The “structural hypothesis,” states that the absence of these envelope proteins result in a weakened cell and would eventually end in nuclear disruption. The “gene regulatory hypothesis” states that emerin and lamin may be transcription factors whose absence results in tissue-specific effects. This review will addresses these hypotheses, describes what is known about the cell and molecular biology underlying EDMD and considers recent as advances in therapeutics.

Nuclear envelope defects associated withLMNAmutations cause dilated cardiomyopathy and Emery-Dreifuss muscular dystrophy

2001 ◽  
Vol 114 (24) ◽  
pp. 4447-4457 ◽  
Author(s):  
Wahyu Hendrati Raharjo ◽  
Paul Enarson ◽  
Teresa Sullivan ◽  
Colin L. Stewart ◽  
Brian Burke
Keyword(s):  
Muscular Dystrophy ◽  
Dilated Cardiomyopathy ◽  
Hela Cells ◽  
Autosomal Dominant ◽  
Nuclear Periphery ◽  
Point Mutations ◽  
Molecular Organization ◽  
Structural Defects ◽  
Lamin A ◽  
Dominant Form

Nuclear lamin A and C alleles that are linked to three distinct human diseases have been expressed both in HeLa cells and in fibroblasts derived from Lmna null mice. Point mutations that cause dilated cardiomyopathy (L85R and N195K) and autosomal dominant Emery-Dreifuss muscular dystrophy (L530P) modify the assembly properties of lamins A and C and cause partial mislocalization of emerin, an inner nuclear membrane protein, in HeLa cells. At the same time, these mutant lamins interfere with the targeting and assembly of endogenous lamins and in this way may cause significant changes in the molecular organization of the nuclear periphery. By contrast, lamin A and C molecules harboring a point mutation (R482W), which gives rise to a dominant form of familial partial lipodystrophy, behave in a manner that is indistinguishable from wild-type lamins A and C, at least with respect to targeting and assembly within the nuclear lamina. Taken together, these results suggest that nuclear structural defects could contribute to the etiology of both dilated cardiomyopathy and autosomal dominant Emery-Dreifuss muscular dystrophy.

scholarly journals Progress in Understanding the Pathogenesis of Oculopharyngeal Muscular Dystrophy

2003 ◽  
Vol 30 (1) ◽  
pp. 8-14 ◽  
Author(s):  
Xueping Fan ◽  
Guy A. Rouleau
Keyword(s):  
Muscular Dystrophy ◽  
Autosomal Dominant ◽  
Oculopharyngeal Muscular Dystrophy ◽  
Intranuclear Inclusions ◽  
Intranuclear Inclusion ◽  
Limb Weakness ◽  
Dominant Form ◽  
Autosomal Dominant Form ◽  
Swallowing Difficulties

Oculopharyngeal muscular dystrophy (OPMD) is an adult-onset disorder characterized by progressive eyelid drooping (ptosis), swallowing difficulties (dysphagia), and proximal limb weakness. The autosomal dominant form of this disease is caused by expansions of a (GCG)6 repeat to (GCG)8-13 in the PABPN1 gene. These mutations lead to the expansion of a polyalanine stretch from 10 to 12-17 alanines in the N-terminal domain of PABPN1. Mutated PABPN1 (mPABPN1) induces the formation of muscle intranuclear inclusions that are thought to be the hallmark of this disease. In this review, we discuss: 1) OPMD genetics and PABPN1 function studies; 2) diseases caused by polyalanine expansions and cellular polyalanine toxicity; 3) mPABPN1-induced intranuclear inclusion toxicity; 4) role of oligomerization of mPABPN1 in the formation and toxicity of OPMD intranuclear inclusions and; 5) recruitment of subcellular components to the OPMD inclusions. We present a potential molecular mechanism for OPMD pathogenesis that accounts for these observations.

The cell cycle dependent mislocalisation of emerin may contribute to the Emery-Dreifuss muscular dystrophy phenotype

2002 ◽  
Vol 115 (2) ◽  
pp. 341-354 ◽  
Author(s):  
Elizabeth A. L. Fairley ◽  
Andrew Riddell ◽  
Juliet A. Ellis ◽  
John Kendrick-Jones
Keyword(s):  
Cell Cycle ◽  
Muscular Dystrophy ◽  
Nuclear Envelope ◽  
Nuclear Membrane ◽  
Transmembrane Domain ◽  
Nuclear Lamina ◽  
Lamin A ◽  
Wild Type ◽  
Cycle Dependent ◽  
Mutant Forms

Emerin is the nuclear membrane protein defective in X-linked Emery-Dreifuss muscular dystrophy (X-EDMD). The majority of X-EDMD patients have no detectable emerin. However, there are cases that produce mutant forms of emerin, which can be used to study its function. Our previous studies have shown that the emerin mutants S54F, P183T, P183H, Del95-99, Del236-241 (identified in X-EDMD patients) are targeted to the nuclear membrane but to a lesser extent than wild-type emerin. In this paper, we have studied how the mislocalisation of these mutant emerins may affect nuclear functions associated with the cell cycle using flow cytometry and immunofluorescence microscopy. We have established that cells expressing the emerin mutant Del236-241 (a deletion in the transmembrane domain), which was mainly localised in the cytoplasm, exhibited an aberrant cell cycle length. Thereafter, by examining the intracellular localisation of endogenously expressed lamin A/C and exogenously expressed wild-type and mutant forms of emerin after a number of cell divisions, we determined that the mutant forms of emerin redistributed endogenous lamin A/C. The extent of lamin A/C redistribution correlated with the amount of EGFP-emerin that was mislocalised. The amount of EGFP-emerin mislocalized, in turn, was associated with alterations in the nuclear envelope morphology. The nuclear morphology and redistribution of lamin A/C was most severely affected in the cells expressing the emerin mutant Del236-241.It is believed that emerin is part of a novel nuclear protein complex consisting of the barrier-to-autointegration factor (BAF), the nuclear lamina, nuclear actin and other associated proteins. The data presented here show that lamin A/C localisation is dominantly directed by its interaction with certain emerin mutants and perhaps wild-type emerin as well. These results suggest that emerin links A-type lamins to the nuclear envelope and that the correct localisation of these nuclear proteins is important for maintaining cell cycle timing.

A Late Autosomal Dominant Form of Limb-Girdle Muscular Dystrophy

1974 ◽  
Vol 12 (3) ◽  
pp. 159-172 ◽  
Author(s):  
W. De Coster ◽  
J. De Reuck ◽  
E. Thiery
Keyword(s):  
Muscular Dystrophy ◽  
Autosomal Dominant ◽  
Limb Girdle Muscular Dystrophy ◽  
Dominant Form ◽  
Autosomal Dominant Form

CADASIL Syndrome: A Genetic Form of Vascular Dementia

1998 ◽  
Vol 11 (2) ◽  
pp. 71-77 ◽  
Author(s):  
Stephen Salloway ◽  
Joseph Hong
Keyword(s):  
Vascular Dementia ◽  
Autosomal Dominant ◽  
Microvascular Disease ◽  
The Elderly ◽  
Dominant Form ◽  
Genetic Features ◽  
Autosomal Dominant Form ◽  
Family Gene ◽  
Cerebral Arteriopathy ◽  
Genetic Form

Mental disorders due to cerebral microvascular disease have been known for over 100 years. Recently, an autosomal dominant form of cerebral arteriopathy (CADASIL) has been described in association with a Notch3 family gene on the short arm of chromosome 19. CADASIL causes subcortical lacunar infarction and dementia in over 80% of cases and depression in a large proportion of patients. Clinically, CADASIL may appear to be very similar to hypertensive microvascular disease (Binswanger's disease), a condition that is seen in the elderly. This article reviews the clinical, pathologic, and genetic features of CADASIL. CADASIL is of interest to neurologists and psychiatrists because it is the first syndrome of vascular dementia and depression with an identified gene. How the gene causes the widespread arteriopathy is not yet known. Insights gained from the study of CADASIL should help us better understand its etiology, as well as the options for treatment of the more common forms of microvascular disease seen in the elderly.

scholarly journals Copy number variation in MODY diabetes - Familial case presentation

2018 ◽  
Vol 2 (2) ◽  
pp. 73
Author(s):  
Naida Lojo-Kadric ◽  
Zelija Velija Asimi ◽  
Jasmin Ramic ◽  
Ksenija Radic ◽  
Lejla Pojskic
Keyword(s):  
Insulin Secretion ◽  
Copy Number ◽  
Autosomal Dominant ◽  
Single Gene ◽  
Maturity Onset Diabetes ◽  
Dominant Form ◽  
Case Presentation ◽  
Monogenic Diseases ◽  
Number Variation ◽  
Autosomal Dominant Form

MODY (maturity-onset diabetes of the young) is an autosomal dominant form of diabetes that is usually manifested before the 25-year of life. This type of diabetes is caused by defects in the primary insulin secretion. There are several types of MODY, which are monogenic diseases, where mutations in a single gene are responsible for a particular type of MODY. Currently, there are eleven types of MODY, from which the most common types are MODY 2 and MODY 3 (with mutations on GCK and HNF1A genes, respectively). We identified very rare MODY 7 type of diabetes in three family members by MLPA analysis.

scholarly journals A New Locus on Chromosome 12p13.3 for Pseudohypoaldosteronism Type II, an Autosomal Dominant Form of Hypertension

2000 ◽  
Vol 67 (2) ◽  
pp. 302-310 ◽  
Author(s):  
Sandra Disse-Nicodème ◽  
Jean-Michel Achard ◽  
Isabelle Desitter ◽  
Anne-Marie Houot ◽  
Albert Fournier ◽  
...  
Keyword(s):  
Autosomal Dominant ◽  
Type Ii ◽  
Dominant Form ◽  
Pseudohypoaldosteronism Type Ii ◽  
Autosomal Dominant Form ◽  
Pseudohypoaldosteronism Type

scholarly journals PCAF Involvement in Lamin A/C-HDAC2 Interplay during the Early Phase of Muscle Differentiation

Cells ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 1735
Author(s):  
Spartaco Santi ◽  
Vittoria Cenni ◽  
Cristina Capanni ◽  
Giovanna Lattanzi ◽  
Elisabetta Mattioli
Keyword(s):  
Muscular Dystrophy ◽  
Early Phase ◽  
Myogenic Differentiation ◽  
Nuclear Lamina ◽  
Muscle Differentiation ◽  
Lamin A ◽  
Histone Deacetylase 2 ◽  
Muscle Gene Expression ◽  
Muscle Gene ◽  
Human Muscle Cells

Lamin A/C has been implicated in the epigenetic regulation of muscle gene expression through dynamic interaction with chromatin domains and epigenetic enzymes. We previously showed that lamin A/C interacts with histone deacetylase 2 (HDAC2). In this study, we deepened the relevance and regulation of lamin A/C-HDAC2 interaction in human muscle cells. We present evidence that HDAC2 binding to lamin A/C is related to HDAC2 acetylation on lysine 75 and expression of p300-CBP associated factor (PCAF), an acetyltransferase known to acetylate HDAC2. Our findings show that lamin A and farnesylated prelamin A promote PCAF recruitment to the nuclear lamina and lamin A/C binding in human myoblasts committed to myogenic differentiation, while protein interaction is decreased in differentiating myotubes. Interestingly, PCAF translocation to the nuclear envelope, as well as lamin A/C-PCAF interaction, are reduced by transient expression of lamin A mutated forms causing Emery Dreifuss muscular dystrophy. Consistent with this observation, lamin A/C interaction with both PCAF and HDAC2 is significantly reduced in Emery–Dreifuss muscular dystrophy myoblasts. Overall, these results support the view that, by recruiting PCAF and HDAC2 in a molecular platform, lamin A/C might contribute to regulate their epigenetic activity required in the early phase of muscle differentiation.

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