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Updated: May 13, 2026
A Non-random Mouse Model for Pharmacological Reactivation of Mecp2 on the Inactive X Chromosome
Published on: May 22, 2019
An AT-hook domain in MeCP2 determines the clinical course of Rett syndrome and related disorders
Steven Andrew Baker1, Lin Chen, Angela Dawn Wilkins
1Program in Developmental Biology, Baylor College of Medicine, Houston, TX 77030, USA.
Abstract:
Mutations in the X-linked MECP2 cause Rett syndrome, a devastating neurological disorder typified by a period of apparently normal development followed by loss of cognitive and psychomotor skills. Data from rare male patients suggest symptom onset and severity can be influenced by the location of the mutation, with amino acids 270 and 273 marking the difference between neonatal encephalopathy and death, on the one hand, and survival with deficits on the other. We therefore generated two mouse models expressing either MeCP2-R270X or MeCP2-G273X. The mice developed phenotypes at strikingly different rates and showed differential ATRX nuclear localization within the nervous system, over time, coinciding with phenotypic progression. We discovered that MeCP2 contains three AT-hook-like domains over a stretch of 250 amino acids, like HMGA DNA-bending proteins; one conserved AT-hook is disrupted in MeCP2-R270X, lending further support to the notion that one of MeCP2's key functions is to alter chromatin structure.
Insights
Mutations in the Methyl CpG Binding Protein 2 (MECP2) gene cause Rett syndrome. Specific mutation locations in males influence disease severity and progression, impacting neurological development.
Area of Science:
- Genetics
- Neuroscience
- Molecular Biology
Background:
- Rett syndrome is a severe neurological disorder caused by mutations in the X-linked MECP2 gene.
- In males, MECP2 mutation location influences symptom onset and severity.
Purpose of the Study:
- To investigate the impact of specific MECP2 mutations (R270X and G273X) on neurological phenotypes in mouse models.
- To explore the relationship between mutation site, disease progression, and ATRX localization.
Main Methods:
- Generated mouse models expressing specific MECP2 mutations (MeCP2-R270X and MeCP2-G273X).
- Monitored phenotypic development and ATRX nuclear localization over time.
Main Results:
- Mice with R270X and G273X mutations exhibited distinct rates of phenotypic development.
- Differential ATRX nuclear localization correlated with phenotypic progression in the nervous system.
- Identified three AT-hook-like domains in MeCP2, with one disrupted in MeCP2-R270X.
Conclusions:
- The location of MECP2 mutations significantly impacts disease progression and neurological deficits.
- MeCP2's function in altering chromatin structure is supported by the disruption of an AT-hook domain in the R270X mutation.
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