Y box-binding protein-1 binds preferentially to single-stranded nucleic acids and exhibits 3'-->5' exonuclease activity.

• We have previously shown that Y box-binding protein-1 (YB-1) binds preferentially to cisplatin-modified Y box sequences. Based on structural and biochemical data, we predicted that this protein binds single-stranded nucleic acids. In the present study we confirmed the prediction and also discovered some unexpected functional features of YB-1. We found that the cold shock domain of the protein is necessary but not sufficient for double-stranded DNA binding while the C-tail domain interacts with both single-stranded DNA and RNA independently of the cold shock domain. In an in vitro translation system the C-tail domain of the protein inhibited translation but the cold shock domain did not. Both in vitro pull-down and in vivo co-immunoprecipitation assays revealed that YB-1 can form a homodimer. Deletion analysis mapped the C-tail domain of the protein as the region of homodimerization. We also characterized an intrinsic 3'-->5' DNA exonuclease activity of the protein. The region between residues 51 and 205 of its 324-amino acid extent is required for full exonuclease activity. Our findings suggest that YB-1 functions in regulating DNA/RNA transactions and that these actions involve different domains.

Ämnesord

MEDICIN OCH HÄLSOVETENSKAP  -- Medicinska och farmaceutiska grundvetenskaper -- Cell- och molekylärbiologi (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Basic Medicine -- Cell and Molecular Biology (hsv//eng)

Nyckelord

Binding Sites

Binding

Competitive

CCAAT-Enhancer-Binding Proteins

chemistry

genetics

metabolism

Cisplatin

pharmacology

DNA

metabolism

DNA

Single-Stranded

metabolism

DNA-Binding Proteins

Dimerization

Exonucleases

metabolism

Glutathione Transferase

genetics

metabolism

Humans

Mutation

NFI Transcription Factors

Nuclear Proteins

Oligonucleotides

metabolism

Protein Binding

drug effects

Protein Biosynthesis

RNA-Binding Proteins

genetics

metabolism

Recombinant Fusion Proteins

genetics

metabolism

Transcription Factors

Tumor Cells

Cultured

Y-Box-Binding Protein 1

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)