Molecular cloning of nucleobindin, a novel DNA-binding protein that contains both a signal peptide and a leucine zipper structure.
We have previously reported that KML1-7 cells cloned from a lupus-prone MRL/l mouse produced a soluble factor that preferentially expanded anti-DNA antibody production across the H-2 barrier. We purified this factor, a 55 kD protein that we termed nucleobindin (Nuc), and obtained its cDNA clone. Although the gene for Nuc encodes a signal peptide and, in fact, Nuc was identified as a secreted protein, Nuc had a DNA-binding property. The putative polypeptide predicted from the cDNA sequence featured a signal peptide, a leucine zipper structure and a basic amino acid-rich region. The DNA-binding property of Nuc was destroyed by deletion of either the leucine zipper structure or the basic amino acid-rich region. The amino acid sequences of Nuc are highly conserved between mouse and human. We discuss the possible role of Nuc in autoimmunity.
Miura
K
K
Institute for Comprehensive Medical Science, Fujita Health University, Aichi, Japan.
Titani
K
K
Kurosawa
Y
Y
Kanai
Y
Y
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002135:Calcium-Binding Proteins; D002460:Cell Line; D003001:Cloning, Molecular; D004247:DNA / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000235:genetics*; D004926:Escherichia coli / Q000235:genetics; D006133:Growth Substances / Q000737:chemistry / Q000235:genetics*; D006801:Humans; D016350:Leucine Zippers / Q000235:genetics*; D051379:Mice; D008969:Molecular Sequence Data; D016296:Mutagenesis; D009419:Nerve Tissue Proteins; D000080866:Nucleobindins; D021382:Protein Sorting Signals / Q000737:chemistry / Q000235:genetics*; D011994:Recombinant Proteins; D012689:Sequence Homology, Nucleic Acid; D013329:Structure-Activity Relationship
D002135:Calcium-Binding Proteins; D004268:DNA-Binding Proteins; D006133:Growth Substances; D009419:Nerve Tissue Proteins; D000080866:Nucleobindins; D021382:Protein Sorting Signals; D011994:Recombinant Proteins; D004247:DNA