TY - JOUR
T1 - Characterization of the DNA-binding protein antigen Ku recognized by autoantibodies from patients with rheumatic disorders
AU - Mimori, T.
AU - Hardin, J. A.
AU - Steitz, J. A.
N1 - Copyright:
Copyright 2004 Elsevier B.V., All rights reserved.
PY - 1986
Y1 - 1986
N2 - We have characterized the biochemical nature of the Ku protein, the antigen recognized by autoantibodies from certain patients with scleroderma, polymyositis overlap syndrome. From extracts of HeLa cells labeled with [32P]orthophosphate, anti-Ku antibodies precipitated a high molecular weight nucleic acid identified as DNA because of sensitivity to DNase I and resistance to RNase. From extracts of cells labeled with [35S]methionine, these antibodies precipitated two polypeptides of 70,000 and 80,000 Da. These proteins were purified using immunoaffinity column chromatography. In immunoblots most sera containing anti-Ku antibodies recognized both Ku proteins but one serum bound only to the 70,000-Da subunit. When nucleosomal segments of chromatin were used as antigen, anti-Ku antibodies precipitated dinucleosomes and larger forms of chromatin but not mononucleosomes. Thus, the Ku antigen is a novel DNA-binding protein that is at least partially exposed on nucleosomal segments of chromatin.
AB - We have characterized the biochemical nature of the Ku protein, the antigen recognized by autoantibodies from certain patients with scleroderma, polymyositis overlap syndrome. From extracts of HeLa cells labeled with [32P]orthophosphate, anti-Ku antibodies precipitated a high molecular weight nucleic acid identified as DNA because of sensitivity to DNase I and resistance to RNase. From extracts of cells labeled with [35S]methionine, these antibodies precipitated two polypeptides of 70,000 and 80,000 Da. These proteins were purified using immunoaffinity column chromatography. In immunoblots most sera containing anti-Ku antibodies recognized both Ku proteins but one serum bound only to the 70,000-Da subunit. When nucleosomal segments of chromatin were used as antigen, anti-Ku antibodies precipitated dinucleosomes and larger forms of chromatin but not mononucleosomes. Thus, the Ku antigen is a novel DNA-binding protein that is at least partially exposed on nucleosomal segments of chromatin.
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M3 - Article
C2 - 3511059
AN - SCOPUS:0023018810
SN - 0021-9258
VL - 261
SP - 2274
EP - 2278
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 5
ER -