Tagging Methyl-CpG-Binding Domain Proteins Reveals Different Spatiotemporal Expression and Supports Distinct Functions

Abstract

Aim: DNA methylation is recognized by methyl-CpG-binding domain (MBD) proteins. Multiple MBDs are linked to neurodevelopmental disorders in humans and mice. However, the functions of MBD2 are poorly understood. We characterized Mbd2 knockout mice and determined spatiotemporal expression of MBDs and MBD2–NuRD (nucleosome remodeling deacetylase) interactions. Experimental procedures: We analyzed behavioral phenotypes, generated biotin-tagged MBD1 and MBD2 knockin mice, and performed biochemical studies of MBD2–NuRD. Results: Most behavioral measures are minimally affected in Mbd2 knockout mice. In contrast to other MBDs, MBD2 shows distinct expression patterns. Conclusion: Unlike most MBDs, MBD2 is ubiquitously expressed in all tissues examined and appears dispensable for brain functions measured in this study. We provide novel genetic tools and reveal new directions to investigate MBD2 functions in vivo.

Keywords::

• chromatin regulation
• DNA-binding protein
• DNA methylation
• gene knockout
• MBD1
• MBD2
• MeCP2
• methyl-CpG-binding domain protein
• mouse genetics
• NuRD

Supplementary data

To view the supplementary data that accompany this paper please visit the journal website at: www.tandfonline.com/doi/full/10.2217/epi-2015-0004

Acknowledgements

The authors thank the Intellectual and Developmental Disabilities Research Center at Children’s Hospital Boston (M Thompson; P30 HD18655) for the generation of Tavi knockin mice. They thank the Neurobehavior Testing Core of the Penn Medicine Neuroscience Center (WT O’Brien) for supporting behavioral tests and all members of the Zhou laboratory for helpful discussion.

Financial & competing interests disclosure

This work was supported by a Predoctoral Training Grant T32GM008216 to KH Wood, US NIH grant R01 MH091850 to Z Zhou, and P50MH096891, Project 2 to ES Brodkin. Z Zhou is a Pew Scholar in the biomedical sciences. Additional support was provided by the Analytical Neurochemistry Core of the Intellectual and Developmental Disabilities Research Center at Children’s Hospital of Philadelphia and the University of Pennsylvania (U54 HD086984). The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

No writing assistance was utilized in the production of this manuscript.

Ethical conduct of research

The authors state that they have obtained appropriate institutional review board approval or have followed the principles outlined in the Declaration of Helsinki for all human or animal experimental investigations. In addition, for investigations involving human subjects, informed consent has been obtained from the participants involved.

Additional information

Funding

This work was supported by a Predoctoral Training Grant T32GM008216 to KH Wood, US NIH grant R01 MH091850 to Z Zhou, and P50MH096891, Project 2 to ES Brodkin. Z Zhou is a Pew Scholar in the biomedical sciences. Additional support was provided by the Analytical Neurochemistry Core of the Intellectual and Developmental Disabilities Research Center at Children’s Hospital of Philadelphia and the University of Pennsylvania (U54 HD086984). The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed. No writing assistance was utilized in the production of this manuscript.