Osteocalcin gene promoter-binding factors are tissue-specific nuclear matrix components
Biochemistry & Molecular Pharmacology
Graduate School of Biomedical Sciences; Department of Cell Biology
Life Sciences | Medicine and Health Sciences
The nuclear matrix appears to play an important role in developmental gene expression during osteoblast differentiation. To better understand this role, we examined nuclear matrix DNA-binding proteins that are sequence-specific and interact with the osteocalcin gene promoter. Multiple protein-DNA interactions involving two distinct nuclear matrix proteins occur within the 5' regulatory sequences (nt -640 to -430). One of these proteins, NMP-1, is a ubiquitous, cell growth-regulated protein that is related to the transcription factor ATF and resides in both the nuclear matrix and the nonmatrix nuclear compartment. The other protein, NMP-2, is a cell type-specific, 38-kDa promoter factor that recognizes binding sites resembling the consensus site for the CCAAT/enhancer-binding protein C/EBP and is localized exclusively on the nuclear matrix. NMP-1 and NMP-2 each interact with two nuclear matrix protein-binding elements. These elements are present near key regulatory sites of the osteocalcin gene promoter, such as the principal steroid hormone (vitamin D)-responsive sequences. Binding in this region of the osteocalcin gene promoter suggests transient associations with the nuclear matrix that are distinct from the stable interactions of matrix attachment regions. Our results are consistent with involvement of the nuclear matrix in concentrating and/or localizing transcription factors that mediate the basal and steroid hormone responsiveness of osteocalcin gene transcription.
Proc Natl Acad Sci U S A. 1993 Apr 15;90(8):3162-6.
Proceedings of the National Academy of Sciences of the United States of America
Bidwell, Joseph P.; Van Wijnen, Andre J.; Fey, Edward G.; Dworetzky, Steven I.; Penman, Sheldon; Stein, Janet L.; Lian, Jane B.; and Stein, Gary S., "Osteocalcin gene promoter-binding factors are tissue-specific nuclear matrix components" (1993). GSBS Student Publications. 99.