Emerin is an inner nuclear membrane protein, which is the gene product resp
onsible for X-linked Emery-Dreifuss muscular dystrophy (X-EDMD). lit this s
tudy we extracted emerin front mammalian cells and examined the DNA binding
property by in vitro binding assay with double-strand DNA cellulose. We pr
epared emerins from two sources; the native emerin in HeLa cells and the re
combinant human emerin produced in COS7. These samples were incubated with
DNA cellulose, and the bound proteins were directly eluted with salt-contai
ning buffers. These elutants were subsequently analyzed by SDS-PAGE and wes
tern blotting. The results showed that 1) both HeLa cell emerin and recombi
nant COS7 emerin were recovered in the elutants of the binding assays, and
2) several other nuclear proteins were always co-isolated in the purificati
on procedure of recombinant COS7 emeriti. These results suggest that emerin
is tightly integrated in some protein "complex" with other nuclear compone
nts and hinds DNA asa protein complex. In this study we demonstrated that e
meriti directly or indirectly binds to DNA.