Disease relevance of Emd

• The product of the X-linked Emery-Dreifuss muscular dystrophy gene is a protein called emerin, which is localized to the nuclear membrane [1].
• Mutated or nonexpressed emerin occurs in patients with muscular dystrophy [2].

High impact information on Emd

• On the basis of the mutations present in these patients, it would appear that emerin possesses two non-overlapping nuclear envelope targeting sequences [1].
• Aberrant intracellular targeting and cell cycle-dependent phosphorylation of emerin contribute to the Emery-Dreifuss muscular dystrophy phenotype [1].
• We have also demonstrated that emerin can occur in four different phosphorylated forms, three of which appear to be associated with the cell cycle [1].
• We have expressed full-length recombinant human emerin in an in vitro coupled reticulocyte system; it has a molecular mass of 34 kDa, inserts into microsomes in a type II orientation, and does not exhibit any N-linked glycosylation or cleavage event [1].
• Expression and subcellular distribution of emerin were studied in lymphoblastoid cell lines established from four patients with Emery-Dreifuss muscular dystrophy containing different mutations in the emerin gene [1].

Biological context of Emd

• Our data suggest that emerin participates in the reorganisation of the nuclear envelope at the end of mitosis [3].
• In contrast to the homogeneous distribution of emerin in the nuclear envelope of interphase cells, this protein shows a focal accumulation in the nuclear membranes of late telophase cells [3].

Anatomical context of Emd

• Emerin increase in regenerating muscle fibers [4].
• The fate of emerin during skeletal muscle regeneration was investigated in an animal model by means of crush injury [4].
• This finding suggests an involvement of emerin during the muscle fiber regeneration process, in analogy with its reported involvement in muscle cell differentiation in vitro [4].

Associations of Emd with chemical compounds

• To verify whether emerin is contained in these membrane stacks, we have induced the formation of AL by exposure of rat cells (line RV-SMC) to sublethal doses of the antimitotic drug vinblastine sulfate and found that emerin is present in the nuclear envelope, but is absent from AL [3].
• However, the RNA level of emerin was not altered under these conditions, implying that the parallel induction of emerin is independent of the sterol regulatory element binding regulation pathway [2].
• To investigate whether sterol regulatory element binding proteins or indirectly cholesterol activates the transcription of stearoyl CoA desaturase and emerin, we cultured Chinese hamster ovary (CHO), either in cholesterol-rich or cholesterol-depleted mediums [2].

Other interactions of Emd

• Induction of stearoyl CoA desaturase is associated with high-level induction of emerin RNA [2].

Analytical, diagnostic and therapeutic context of Emd

• Emerin protein was detected in two of these patients by immunoblotting [1].
• Confocal laser scanning microscopy after double-labeling experiments with emerin and tubulin shows that emerin is concentrated in areas of the mitotic spindle and in the midbody of mitotic cells suggesting a close interaction of these proteins [3].

References