The nuclear matrix protein NMP-1 is the transcription factor YY1
Department of Cell Biology
Medical Subject Headings
Animals; Antibody Specificity; Base Sequence; Binding Sites; Blotting, Western; Cell Compartmentation; Cell Nucleolus; Cell Nucleus; Cross Reactions; DNA; DNA-Binding Proteins; purification; Erythroid-Specific DNA-Binding Factors; Hela Cells; Humans; Molecular Sequence Data; Nuclear Matrix; Oligodeoxyribonucleotides; Protein Binding; Rats; Recombinant Proteins; Transcription Factors; purification; YY1 Transcription Factor
Cell Biology | Life Sciences | Medicine and Health Sciences
NMP-1 was initially identified as a nuclear matrix-associated DNA-binding factor that exhibits sequence-specific recognition for the site IV regulatory element of a histone H4 gene. This distal promoter domain is a nuclear matrix interaction site. In the present study, we show that NMP-1 is the multifunctional transcription factor YY1. Gel-shift and Western blot analyses demonstrate that NMP-1 is immunoreactive with YY1 antibody. Furthermore, purified YY1 protein specifically recognizes site IV and reconstitutes the NMP-1 complex. Western blot and gel-shift analyses indicate that YY1 is present within the nuclear matrix. In situ immunofluorescence studies show that a significant fraction of YY1 is localized in the nuclear matrix, principally but not exclusively associated with residual nucleoli. Our results confirm that NMP-1/YY1 is a ubiquitous protein that is present in both human cells and in rat osteosarcoma ROS 17/2.8 cells. The finding that NMP-1 is identical to YY1 suggests that this transcriptional regulator may mediate gene-matrix interactions. Our results are consistent with the concept that the nuclear matrix may functionally compartmentalize the eukaryotic nucleus to support regulation of gene expression.
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Citation: Proc Natl Acad Sci U S A. 1995 Nov 7;92(23):10526-30.