The MMSET protein is a histone methyltransferase with characteristics of a transcriptional corepressor.

MMSET, identified by its fusion to the IgH locus in t(4;14)-associated multiple myeloma, possesses domains found within chromatin regulators, including the SET domain. MMSET protein is overexpressed and highly associated with chromatin in myeloma cell lines carrying t(4;14). MMSET possesses methyltransferase activity for core histone H3 lysine 4 and histone ...
4 lysine 20, whereas MMSET made in cells only modified H4. Segments of MMSET fused to the Gal4 DNA binding domain repressed transcription of a chromatin-embedded Gal4 reporter gene. MMSET-mediated repression was associated with increased H4K20 methylation gene and loss of histone acetylation. Consistent with this repressive activity, MMSET could form a complex with HDAC1 and HDAC2, mSin3a, and the histone demethylase LSD1, suggesting that it is a component of corepressor complexes. Furthermore, MMSET coexpression enhances HDAC1- and HDAC2-mediated repression in transcriptional reporter assays. Finally, shRNA-mediated knockdown of MMSET compromised viability of a myeloma cell line, suggesting a biologic role for the protein in malignant cell growth. Collectively, these data suggest that, by acting directly as a modifier of chromatin as well as through binding of other chromatin-modifying enzymes, MMSET influences gene expression and potentially acts as a pathogenic agent in multiple myeloma.
Mesh Terms:
Animals, Catalysis, Cell Line, Cell Nucleus, Cell Survival, Chromosomes, Human, Pair 4, Gene Expression Regulation, Histone-Lysine N-Methyltransferase, Histones, Humans, Isoenzymes, Melanoma, Mice, Models, Molecular, Protein Binding, Protein Structure, Tertiary, Rabbits, Repressor Proteins, Transcription, Genetic
Blood
Date: Mar. 15, 2008
Download Curated Data For This Publication
94243
Switch View:
  • Interactions 8