Enhancer Of mRNA Decapping Protein 4 (EDC4)

RCD8 promoted the association of DCP1A and DCP2, and overexpressed DCP1A and DCP2 did not associate in its absence. RCD8 associated with DCP2 and stimulated its decapping activity in vitro. The deduced 1,215-amino acid protein contains a central serine-rich region and a putative nuclear localization sequence (NLS) near its C terminus; however, it lacks zinc finger, leucine zipper, and RNA-binding motifs, which are found in other autoantigens. Immunoblot analysis indicated that GE1 is expressed as a 160-kD protein. Epitope mapping analysis suggested that the functional NLS-containing hydrophilic region of GE1 is the site recognized by patient serum. Immunofluorescence microscopy using rat antisera to the recombinant protein demonstrated speckled, mostly nuclear expression.