The Emery-Dreifuss muscular dystrophy protein, emerin, is a nuclear membrane protein.
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 emerin-related 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 immunohistochemistry, 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.
Manilal
S
S
MRIC Biotechnology Group, N.E. Wales Institute, UK.
Nguyen
T M
TM
Sewry
C A
CA
Morris
G E
GE
D000328:Adult; D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D002467:Cell Nucleus / Q000378:metabolism; D018604:Epitope Mapping; D005333:Fetus / Q000378:metabolism; D006801:Humans; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D009132:Muscles / Q000378:metabolism; D009136:Muscular Dystrophies / Q000378:metabolism* / Q000473:pathology; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D011817:Rabbits; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D013946:Thymopoietins / Q000235:genetics / Q000378:metabolism*
D000911:Antibodies, Monoclonal; D008565:Membrane Proteins; D009687:Nuclear Proteins; D011993:Recombinant Fusion Proteins; D013946:Thymopoietins; C092710:emerin