The Nuclear Matrix Protein NMP-1 is the Transcription Factor YY1

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 92; no. 23; pp. 10526 - 10530
• Main Authors: Guo, Bo, Odgren, Paul R., van Wijnen, Andre J., Last, Thomas J., Nickerson, Jeffrey, Penman, Sheldon, Lian, Jane B., Stein, Janet L., Stein, Gary S.
• Format: Journal Article
• Language: English
• Published: United States National Academy of Sciences of the United States of America 07-11-1995; National Acad Sciences; National Academy of Sciences
• Subjects: Activating transcription factors; Animals; Antibodies; Antibody Specificity; Base Sequence; Binding Sites; Blotting, Western; Cell Compartmentation; Cell Nucleolus - chemistry; Cell Nucleolus - ultrastructure; Cell Nucleus - chemistry; Cell Nucleus - ultrastructure; Cellular biology; Cross Reactions; DNA; DNA - metabolism; DNA-Binding Proteins - genetics; DNA-Binding Proteins - immunology; DNA-Binding Proteins - isolation & purification; DNA-Binding Proteins - metabolism; Erythroid-Specific DNA-Binding Factors; Genes; Genetics; Globalization; HeLa Cells; Humans; Molecular Sequence Data; Nuclear interactions; Nuclear matrix; Nuclear Matrix - chemistry; Nuclear matrix associated proteins; Oligodeoxyribonucleotides - metabolism; Oligonucleotides; Protein Binding; Proteins; Rats; Recombinant Proteins - isolation & purification; Recombinant Proteins - metabolism; Transcription factors; Transcription Factors - genetics; Transcription Factors - immunology; Transcription Factors - isolation & purification; Transcription Factors - metabolism; YY1 Transcription Factor
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.92.23.10526

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.