cDNA cloning of a novel autoantigen targeted by a minor subset of anti-centromere antibodies.
Using autoimmune serum from a patient with anti-centromere antibodies, we have identified and partially characterized a novel protein with a mol. wt of approximately 27 kD (hereafter referred to as p27). A cDNA expression library was screened with this serum, and two overlapping inserts were isolated among three positive clones other than clones corresponding to centromere protein (CENP)-B and CENP-C. Analysis of the sequence showed an open reading frame of approximately 0.6 kb encoding 199 amino acids with a predicted mol. wt of 21.5 kD. Immunoblotting analysis with bacterial recombinant p27 showed that approximately 2% of anti-centromere antibody-positive patients had autoantibodies to p27, whereas only one of 215 autoimmune patients without anti-centromere antibodies reacted with the recombinant. All five cases with anti-p27 antibodies, who were diagnosed as having scleroderma and/or Sjögren's syndrome, showed internal organ involvement. Although affinity-purified anti-p27 human or mouse polyclonal antibodies failed to stain any cellular structures in an immunofluorescence study, the potential association of anti-p27 with anti-centromere antibodies suggests that this novel autoantigen might play a role in mitosis.
Muro
Y
Y
Department of Dermatology, Nagoya University School of Medicine, Japan.
Yamada
T
T
Himeno
M
M
Sugimoto
K
K
D000368:Aged; D000595:Amino Acid Sequence; D000818:Animals; D001323:Autoantibodies / Q000097:blood / Q000276:immunology; D001324:Autoantigens / Q000097:blood / Q000235:genetics* / Q000276:immunology; D001483:Base Sequence; D015153:Blotting, Western; D002503:Centromere / Q000276:immunology*; D051936:Centromere Protein B; D002868:Chromosomal Proteins, Non-Histone / Q000235:genetics / Q000276:immunology; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D004268:DNA-Binding Proteins; D005260:Female; D006801:Humans; D008297:Male; D051379:Mice; D008875:Middle Aged; D008969:Molecular Sequence Data; D012859:Sjogren's Syndrome / Q000097:blood / Q000276:immunology
D001323:Autoantibodies; D001324:Autoantigens; C497926:CENPB protein, human; C497927:Cenpb protein, mouse; D051936:Centromere Protein B; D002868:Chromosomal Proteins, Non-Histone; D018076:DNA, Complementary; D004268:DNA-Binding Proteins; C060905:centromere protein C