Hormone Receptors and the Nuclear Matrix

ATP-Dependent Release of Glucocorticoid Receptors from the Nuclear Matrix

“…16,1996 GLUCOCORTICOID RECEPTORS AND THE NUCLEAR MATRIX 1997 past 15 years (2,3,27). The in vitro binding of steroid receptors to the nuclear matrix is saturable, high affinity, and hormone dependent (2,50,66). Although nuclear matrix binding of human AR is mainly directed by its LBD (74), the DBD appears to possess the predominant nuclear matrix-binding domain of human (74) and rat (this study) GRs.…”

“…The centrally located DNAbinding domain (DBD) and carboxy-terminal ligand-binding domain (LBD) are required for nuclear matrix binding of the androgen receptor and glucocorticoid receptor (GR), although the relative contributions of the DBD and LBD to matrix binding differ between these two highly related proteins (74). The relative proportions of steroid receptors, particularly the sex steroid receptors (2), that are bound to the nuclear matrix vary among different target tissues. A 10-kDa protein isolated from chick oviduct nuclear matrix binds with high affinity and specificity to the progesterone receptor (PR) (66), suggesting that specific acceptor proteins may be responsible for cell type differences in steroid receptor binding to the matrix.…”

“…16,1996 GLUCOCORTICOID RECEPTORS AND THE NUCLEAR MATRIX 1997 past 15 years (2,3,27). The in vitro binding of steroid receptors to the nuclear matrix is saturable, high affinity, and hormone dependent (2,50,66).…”

Osteocalcin gene promoter-binding factors are tissue-specific nuclear matrix components.

“…There is other evidence of nuclear matrix contribution to the regulation of gene expression. This includes the preferential association of actively transcribed genes with the matrix (8)(9)(10)(11)(12), the localization of RNA synthesis and pre-mRNA splicing on the matrix (13)(14)(15), and the presence of steroid receptors in the matrix fraction (16)(17)(18). Our recent studies showed that a cell cycle-regulated histone gene interacts with the nuclear matrix when actively transcribed in proliferating cells and that a sequence-specific, activating transcription factor (ATF)-related histone gene promoterbinding factor associates with the nuclear matrix (19).…”

Sequence-specific DNA-binding proteins are components of a nuclear matrix-attachment site.

“…However, it remains to be established how the nuclear matrix supports this organization of chromatin, and more importantly, the biochemical composition and sequence specificity of these anchorage sites are only beginning to be defined (6). The nuclear matrix has also been reported to have a role in mRNA transcription and processing via its involvement in attachment and/or association with newly transcribed mRNA (9), ribonucleoprotein particles (10), pre-mRNA splicing machinery (11,12), and steroid receptors (13,14). To attribute structure-function relationships to these reported associations, it is essential to characterize the nuclear matrix proteins involved and the nature of their interactions.…”