Originally Published In
Saunders WS, Chue C, Goebl M, et al. Molecular cloning of a human homologue of Drosophila heterochromatin protein HP1 using anti-centromere autoantibodies with anti-chromo specificity. J Cell Sci. 1993;104 ( Pt 2):573–582.
We have identified a novel autoantibody specificity in scleroderma that we term anti-chromo. These antibodies recognize several chromosomal antigens with apparent molecular mass of between 23 and 25 kDa, as determined by immunoblots. Anti-chromo autoantibodies occur in 10-15% of sera from patients with anti-centromere antibodies (ACA). We used anti-chromo antibodies to screen a human expression library and obtained cDNA clones encoding a 25 kDa chromosomal autoantigen. DNA sequence analysis reveals this protein to be a human homologue of HP1, a heterochromatin protein of Drosophila melanogaster. We designate our cloned protein HP1Hs alpha. Epitope mapping experiments using both human and Drosophila HP1 reveal that anti-chromo antibodies target a region at the amino terminus of the protein. This region contains a conserved motif, the chromo domain (or HP1/Pc box), first recognized by comparison of Drosophila HP1 with the Polycomb gene product. Both proteins are thought to play a role in creating chromatin structures in which gene expression is suppressed. Anti-chromo thus defines a novel type of autoantibody that recognizes a conserved structural motif found on a number of chromosomal proteins.
Saunders, W; Chue, C; Goebl, M; Craig, Carolyn; Clark, Robert F.; Powers, J; Eissenberg, J; Elgin, Sarah C.R.; Rothfield, N; and Earnshaw, W, "Molecular cloning of a human homologue of Drosophila heterochromatin protein HP1 using anti-centromere autoantibodies with anti-chromo specificity" (1993). Biology Faculty Publications & Presentations. 215.