The Emery-Dreifuss Muscular Dystrophy Protein, Emerin, is a Nuclear Membrane Protein

• Published in: Human molecular genetics Vol. 5; no. 6; pp. 801 - 808
• Main Authors: Manilal, S., Man, Nguyen thi, Sewry, C. A., Morris, G. E.
• Format: Journal Article
• Language: English
• Published: Oxford Oxford University Press 01.06.1996
• Subjects: Adult; Animals; Antibodies, Monoclonal - immunology; Biological and medical sciences; Cell Nucleus - metabolism; Diseases of striated muscles. Neuromuscular diseases; Epitope Mapping; Escherichia coli; Fetus - metabolism; Humans; Medical sciences; Membrane Proteins - genetics; Membrane Proteins - metabolism; Muscles - metabolism; Muscular Dystrophies - metabolism; Muscular Dystrophies - pathology; Neurology; Nuclear Proteins - genetics; Nuclear Proteins - metabolism; Rabbits; Recombinant Fusion Proteins - genetics; Recombinant Fusion Proteins - metabolism; Thymopoietins - genetics; Thymopoietins - metabolism; Human; Neuromuscular diseases; Nervous system diseases; Membrane protein; Pathogenesis; Gene product; Monoclonal antibody; Gene expression; Nuclear envelope; Genetic disease; Emery Dreifuss muscular dystrophy; Genetics; Diagnosis; Localization
• ISSN: 0964-6906; 1460-2083; 1460-2083
• DOI: 10.1093/hmg/5.6.801

A large fragment of emerin cDNA was prepared by PCR and expressed as a recombinant protein in Escherichia coli. Using this as immunogen, we prepared a panel of 12 monoclonal antibodies which recognise at least four different epitopes on emerin in order to ensure that emerin can be distinguished from non-specific cross-reacting proteins. All the mAbs recognised a 34 kDa protein in all tissues tested, though minor emerinrelated bands were also detected in some tissues. Immunofluorescence microscopy showed that emerin is located at the nuclear rim in all tissues examined. A muscle biopsy from an Emery-Dreifuss muscular dystrophy (EMDM) patient showed complete absence of emerin by both Western blotting and immunohisto-chemistry, suggesting a simple diagnostic antibody test for EDMD families. Biochemical fractionation of brain and liver tissues showed that emerin was present in nuclei purified by centrifugation through 65% sucrose and was absent from soluble fractions (post-100 000 g). From these results, together with sequence and structural homologies between emerin, thymopoietins and the nuclear lamina-associated protein, LAP2, we suggest that emerin will prove to be one member of a family of inner nuclear membrane proteins.