Background: MMP-9 plays a direct role in the activation of pro-osteoclastogenic genes by cleaving histone H3N-terminal tail (H3NT) and altering chromatin architecture. Although H3 acetylation at K18 has been shown to stimulate MMP-9 enzymatic activity toward H3NT, nothing is known about the influence of other H3NT modifications on this epigenetic reaction.
Results: We show that H3 monomethylation at lysine 27 (H3K27me1) is essential for MMP-9-dependent H3NT proteolysis during RANKL-induced osteoclast differentiation. Through the recognition of H3K27me1 mark, MMP-9 localizes and generates H3NT proteolysis at the genes encoding osteoclast differentiation factors. By using RNAi and small molecule inhibitor approaches, we also confirmed that G9a is the major methyltransferase to catalyze H3K27me1 for MMP-9-dependent H3NT proteolysis and trigger the expression of osteoclast-specific genes.
Conclusions: Our data establish new functions for G9a-mediated H3K27me1 in MMP-9-dependent H3NT proteolysis and demonstrate how histone modification can be exploited to regulate osteoclastogenic gene expression at the molecular level. Further studies are warranted to investigate the detailed mechanism by which G9a overexpression with concomitant dysregulation of osteoclastogenesis contributes to the pathogenesis of bone disorders.
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http://dx.doi.org/10.1186/s13072-018-0193-1 | DOI Listing |
Mol Oncol
August 2024
Department of Biochemistry and Molecular Medicine, Norris Comprehensive Cancer Center, University of Southern California, Los Angeles, CA, USA.
Matrix metalloproteinase 9 (MMP-9) is a member of the MMP family and has been recently identified as a nuclear protease capable of clipping histone H3 N-terminal tails (H3NT). This MMP-9-dependent H3NT proteolysis is critical for establishing an active state of gene transcription during osteoclast differentiation and melanoma development. However, whether H3NT cleavage by MMP-9 plays a similar role in other cellular events has not been explored.
View Article and Find Full Text PDFEpigenetics Chromatin
May 2023
Department of Biochemistry and Molecular Medicine, University of Southern California Keck School of Medicine, 1450 Biggy Street, HNRT 6506, Los Angeles, CA, 90033, USA.
Background: Proteolysis of the histone H3 N-terminal tail (H3NT) is an evolutionarily conserved epigenomic feature of nearly all eukaryotes, generating a cleaved H3 product that is retained in ~ 5-10% of the genome. Although H3NT proteolysis within chromatin was first reported over 60 years ago, the genomic sites targeted for H3NT proteolysis and the impact of this histone modification on chromatin structure and function remain largely unknown. The goal of this study was to identify the specific regions targeted for H3NT proteolysis and investigate the consequence of H3NT "clipping" on local histone post-translational modification (PTM) dynamics.
View Article and Find Full Text PDFOncogene
January 2022
Department of Biochemistry and Molecular Medicine, Norris Comprehensive Cancer Center, University of Southern California, Los Angeles, CA, 90033, USA.
Melanoma is a type of skin cancer that develops in pigment-producing melanocytes and often spreads to other parts of the body. Aberrant gene expression has been considered as a crucial step for increasing the risk of melanomagenesis, but how chromatin reorganization contributes to this pathogenic process is still not well understood. Here we report that matrix metalloproteinase 9 (MMP-9) localizes to the nucleus of melanoma cells and potentiates gene expression by proteolytically clipping the histone H3 N-terminal tail (H3NT).
View Article and Find Full Text PDFEpigenetics Chromatin
May 2021
Department of Biochemistry and Molecular Medicine, Norris Comprehensive Cancer Center, University of Southern California Keck School of Medicine, 1450 Biggy Street, HNRT 6506, Los Angeles, CA, 90033, USA.
Background: Selective proteolysis of the histone H3 N-terminal tail (H3NT) is frequently observed during eukaryotic development, generating a cleaved histone H3 (H3cl) product within a small, but significant, portion of the genome. Although increasing evidence supports a regulatory role for H3NT proteolysis in gene activation, the nuclear H3NT proteases and the biological significance of H3NT proteolysis remain largely unknown.
Results: In this study, established cell models of skeletal myogenesis were leveraged to investigate H3NT proteolysis.
Epigenetics Chromatin
April 2019
Department of Biochemistry and Molecular Medicine, Norris Comprehensive Cancer Center, University of Southern California, Los Angeles, CA, 90089, USA.
Background: MMP-9-dependent proteolysis of histone H3 N-terminal tail (H3NT) is an important mechanism for activation of gene expression during osteoclast differentiation. Like other enzymes targeting their substrates within chromatin structure, MMP-9 enzymatic activity toward H3NT is tightly controlled by histone modifications such as H3K18 acetylation (H3K18ac) and H3K27 monomethylation (H3K27me1). Growing evidence indicates that DNA methylation is another epigenetic mechanism controlling osteoclastogenesis, but whether DNA methylation is also critical for regulating MMP-9-dependent H3NT proteolysis and gene expression remains unknown.
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