A B-cell-specific DNA recombination complex
Research output: Contribution to journal › Research article › Contributed › peer-review
Contributors
Abstract
We have purified and biochemically characterized a multiprotein complex designated SWAP. In a DNA transfer assay, SWAP preferentially recombines ("swaps") sequences derived from Ig heavy chain switch regions. We identified four of the proteins in the SWAP complex: B23 (nucleophosmin), C23 (nucleolin), poly(ADP-ribose) polymerase (PARP), and SWAP-70. The first three are proteins known to be present in most cells. B23 promotes single-strand DNA reannealing and the formation of joint molecules in a D-loop assay between homologous, but also between Smu and Sgamma sequences. SWAP-70 is a novel protein of 70 kDa. Its cDNA was cloned and sequenced, and the protein was overexpressed in Escherichia coli. SWAP-70 protein expression was found only in B lymphocytes that had been induced to switch to various Ig isotypes and in switching B-cell lines. SWAP-70 is a nuclear protein, has a weak affinity for DNA, binds ATP, and forms specific, high affinity complexes with B23, C23, and poly(ADP-ribose) polymerase. These findings are consistent with SWAP being the long elusive "switch recombinase" and with SWAP-70 being the specific recruiting element that assembles the switch recombinase from universal components.
Details
Original language | English |
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Pages (from-to) | 17025-35 |
Number of pages | 11 |
Journal | The Journal of biological chemistry |
Volume | 273 |
Issue number | 27 |
Publication status | Published - 3 Jul 1998 |
Peer-reviewed | Yes |
Externally published | Yes |
External IDs
Scopus | 0032479427 |
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Keywords
Keywords
- Adenosine Triphosphate/metabolism, Amino Acid Sequence, Animals, B-Lymphocytes/metabolism, Base Sequence, Cloning, Molecular, DNA, Recombinant/genetics, DNA-Binding Proteins/genetics, Escherichia coli/genetics, Guanine Nucleotide Exchange Factors, Hot Temperature, Kinetics, Mice, Mice, Inbred C57BL, Minor Histocompatibility Antigens, Molecular Sequence Data, Nuclear Proteins/genetics, Nucleophosmin, Phosphoproteins/metabolism, Poly(ADP-ribose) Polymerases/metabolism, Protein Binding, Recombination, Genetic