Transient Expression of Adipogenic Transcription Factor Zfp423 Regulates Muscle Satellite Cell Function
Transcriptional control of proliferation and differentiation within muscle stem cells is critical for the repair and regeneration of skeletal muscle tissue following injury or disease. Addison et al. (e00447-18) identify Zfp423, an adipogenic transcription factor, as a regulator of population expansion and myogenic progression in muscle stem cells. They show that Zfp423 is transiently and dynamically expressed upon activation of satellite cells and demonstrate that in vivo satellite cell-specific deletion of Zfp423 impedes muscle repair. In contrast, sustained misexpression of Zfp423 transforms myoblasts into adipocyte-like cells. These findings provide new insights into the role of Zfp423 in mesenchymal progenitor cells.
Roles of the E3 Ubiquitin Ligases RNF20 and RNF40 in DNA Repair
Histone posttranslational modifications play a significant role in modulating DNA repair. While several histone modifications are known to signal the presence of DNA damage and/or recruit enzymes to DNA lesions, the roles of many other histone modifications in DNA repair remain to be characterized. So et al. (e00488-18) describe a role for monoubiquitination of histone H2B by the E3 ubiquitin ligases RNF20 and RNF40 in DNA repair. Ubiquitination of H2B by RNF20 and RNF40 after DNA damage is likely regulated by kinases ATM and ATR. These findings posit H2B ubiquitination as a distinct pathway in the DNA damage response.
- Copyright © 2019 American Society for Microbiology.
