The R882H DNMT3A hot spot mutation stabilizes the formation of large DNMT3A oligomers with low DNA methyltransferase activity
| Autor: | David M. Bolduc, Nicholas A. Larsen, Alan Rolfe, Tuong-Vi Nguyen, Rachel B. Darman, Pete Smith, Markus Warmuth, Peter Fekkes, Yahong Wang, Lihua Yu, Ping Zhu, Frédéric H. Vaillancourt, Shihua Yao, Anand Selvaraj, Jiyuan Ke |
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| Rok vydání: | 2019 |
| Předmět: |
Models
Molecular 0301 basic medicine Biochemistry Genome DNA methyltransferase DNA Methyltransferase 3A 03 medical and health sciences Mutant protein Humans DNA (Cytosine-5-)-Methyltransferases Epigenetics Protein Structure Quaternary Molecular Biology chemistry.chemical_classification 030102 biochemistry & molecular biology Hematopoietic stem cell differentiation Point mutation DNA Cell Biology Cell biology 030104 developmental biology Enzyme chemistry Mutation embryonic structures DNA methylation Enzymology Protein Multimerization |
| Zdroj: | J Biol Chem |
| ISSN: | 0021-9258 |
| Popis: | DNMT3A (DNA methyltransferase 3A) is a de novo DNA methyltransferase responsible for establishing CpG methylation patterns within the genome. DNMT3A activity is essential for normal development, and its dysfunction has been linked to developmental disorders and cancer. DNMT3A is frequently mutated in myeloid malignancies with the majority of mutations occurring at Arg-882, where R882H mutations are most frequent. The R882H mutation causes a reduction in DNA methyltransferase activity and hypomethylation at differentially-methylated regions within the genome, ultimately preventing hematopoietic stem cell differentiation and leading to leukemogenesis. Although the means by which the R882H DNMT3A mutation reduces enzymatic activity has been the subject of several studies, the precise mechanism by which this occurs has been elusive. Herein, we demonstrate that in the context of the full-length DNMT3A protein, the R882H mutation stabilizes the formation of large oligomeric DNMT3A species to reduce the overall DNA methyltransferase activity of the mutant protein as well as the WT–R882H complex in a dominant-negative manner. This shift in the DNMT3A oligomeric equilibrium and the resulting reduced enzymatic activity can be partially rescued in the presence of oligomer-disrupting DNMT3L, as well as DNMT3A point mutations along the oligomer-forming interface of the catalytic domain. In addition to modulating the oligomeric state of DNMT3A, the R882H mutation also leads to a DNA-binding defect, which may further reduce enzymatic activity. These findings provide a mechanistic explanation for the observed loss of DNMT3A activity associated with the R882H hot spot mutation in cancer. |
| Databáze: | OpenAIRE |
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