Open AccessCloning and nucleotide sequence of cDNA for Ki antigen, a highly conserved nuclear protein detected with sera from patients with systemic lupus erythematosus
Author(s) -
NIKAIDO T.,
SHIMADA K.,
SHIBATA M.,
HATA M.,
SAKAMOTO M.,
TAKASAKI Y.,
SATO C.,
TAKAHASHI T.,
NISHIDA Y.
Publication year - 1990
Publication title -
clinical & experimental immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.329
H-Index - 135
eISSN - 1365-2249
pISSN - 0009-9104
DOI - 10.1111/j.1365-2249.1990.tb05180.x
Subject(s) - complementary dna , antigen , autoantibody , biology , nucleic acid sequence , microbiology and biotechnology , molecular cloning , gene , cloning (programming) , lupus erythematosus , peptide sequence , antibody , escherichia coli , cdna library , extractable nuclear antigens , virology , immunology , genetics , anti nuclear antibody , computer science , programming language
SUMMARY Patients with systemic lupus erythematosus (SLE) produce autoantibodies against a variety of nuclear antigens including Ki antigen. Although anti‐Ki autoantibodies were found in a significant number of SLE patients, the nature of Ki antigen is poorly characterized. By using anti‐Ki serum as a probe we have cloned a bovine cDNA directing the synthesis in Escherichia coli of a polypeptide immunologically indistinguishable from the authentic Ki antigen. A homologous human cDNA was also cloned and its nucleotide sequence predicted the entire primary structure of a novel nuclear protein with a molecular weight of 29 508 and with highly hydrophilic and weakly acidic character. The gene is highly conserved not only in the coding region but also in the 3′‐untranslated region. The bacterially produced Ki antigen would be valuable for diagnosis of SLE.