The Caenorhabditis elegans rop-1 gene encodes the homologue of the human 60-kDa Ro autoantigen

As a first step toward establishing a genetic system for the elucidation of the cellular role(s) of the Ro ribonucleoproteins (RoRNP), we have cloned the gene encoding the homologue of the human 60-kDa Ro protein (Ro60) in Caenorhabditis elegans (Ce). This Ce gene is present as a single copy and contains a 643-codon open reading frame interrupted by three introns. The encoded protein, Rop1p, shares 40% identity and 63% overall similarity with both the human and amphibian Ro60. Recombinant protein has been produced in Escherichia coli and used to elicit anti-Rop1p antibodies. Immunological analysis indicated that the Ro60 epitopes have been poorly conserved. Gene-fusion expression studies in transgenic nematodes will provide a new avenue of research to shed light on the function of these particles.