LBP-p40 binds DNA tightly through associations with histones H2A, H2B, and H4.
Laminin binding protein precursor p40 (LBP-p40) was long believed to be located exclusively in the cytoplasm. We recently reported localization of epitope-tagged LBP-p40 to the nucleus tightly associated with nuclear structure as well as on ribosomes. In this paper, we analyze the interaction of LBP-p40 with DNA and nuclear proteins in vitro. LBP-p40 was found to bind to a double-stranded DNA cellulose column at moderate salt. However, when mixed with a high salt nuclear extract, LBP-p40 was eluted from the DNA cellulose column only at higher salt. An LBP-p40 affinity column indicated that both histone H1 and in particular the core histones associate with LBP-p40. Using recombinant core histone molecules fused with glutathione S-transferase (GST), we demonstrate that histones H2A, H2B, and H4 are capable of interacting with LBP-p40, whereas H3 is not. These results suggest that association of LBP-p40 with histones H2A, H2B, and H4 confers tight binding of LBP-p40 to chromatin DNA in the nucleus.
Kinoshita
K
K
Division of Gene Therapy Science, Osaka University School of Medicine, Japan.
Kaneda
Y
Y
Sato
M
M
Saeki
Y
Y
Wataya-Kaneda
M
M
Hoffmann
A
A
D000818:Animals; D002286:Carcinoma, Ehrlich Tumor; D002482:Cellulose / Q000031:analogs & derivatives / Q000378:metabolism; D004247:DNA / Q000378:metabolism; D006367:HeLa Cells; D006657:Histones / Q000378:metabolism*; D006801:Humans; D051379:Mice; D009687:Nuclear Proteins / Q000378:metabolism; D011485:Protein Binding; D011498:Protein Precursors / Q000378:metabolism*; D017474:Receptors, Laminin / Q000378:metabolism*; D012269:Ribosomal Proteins / Q000378:metabolism; D014407:Tumor Cells, Cultured
C033190:DNA-cellulose; D006657:Histones; D009687:Nuclear Proteins; D011498:Protein Precursors; D017474:Receptors, Laminin; D012269:Ribosomal Proteins; D002482:Cellulose; D004247:DNA