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Kalani L, Kim BH, de Chavez AR, Roemer A, Mikhailov A, Merritt JK, Good KV, Chow RL, Delaney KR, Hendzel MJ, Zhou Z, Neul JL, Vincent JB, Ausió J. Testing the PEST hypothesis using relevant Rett mutations in MeCP2 E1 and E2 isoforms. Hum Mol Genet 2024:ddae119. [PMID: 39137370 DOI: 10.1093/hmg/ddae119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2024] [Revised: 07/19/2024] [Accepted: 08/07/2024] [Indexed: 08/15/2024] Open
Abstract
Mutations in methyl-CpG binding protein 2 (MeCP2), such as the T158M, P152R, R294X, and R306C mutations, are responsible for most Rett syndrome (RTT) cases. These mutations often result in altered protein expression that appears to correlate with changes in the nuclear size; however, the molecular details of these observations are poorly understood. Using a C2C12 cellular system expressing human MeCP2-E1 isoform as well as mouse models expressing these mutations, we show that T158M and P152R result in a decrease in MeCP2 protein, whereas R306C has a milder variation, and R294X resulted in an overall 2.5 to 3 fold increase. We also explored the potential involvement of the MeCP2 PEST domains in the proteasome-mediated regulation of MeCP2. Finally, we used the R294X mutant to gain further insight into the controversial competition between MeCP2 and histone H1 in the chromatin context. Interestingly, in R294X, MeCP2 E1 and E2 isoforms were differently affected, where the E1 isoform contributes to much of the overall protein increase observed, while E2 decreases by half. The modes of MeCP2 regulation, thus, appear to be differently regulated in the two isoforms.
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Affiliation(s)
- Ladan Kalani
- Department of Biochemistry and Microbiology, University of Victoria, 3800 Finnerty Rd, Victoria, BC V8W 2Y2, Canada
| | - Bo-Hyun Kim
- Department of Biochemistry and Microbiology, University of Victoria, 3800 Finnerty Rd, Victoria, BC V8W 2Y2, Canada
| | - Alberto Ruiz de Chavez
- Department of Biology, University of Victoria, 3800 Finnerty Rd, Victoria, BC V8W 2Y2, Canada
| | - Anastasia Roemer
- Departments of Oncology and Cell Biology, Faculty of Medicine and Dentistry, University of Alberta, 11560 University Ave, Edmonton, AB T6G 2H7, Canada
| | - Anna Mikhailov
- Molecular Neuropsychiatry & Development (MiND) Lab, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, 250 College St, Toronto, ON M5T 1R8, Canada
| | - Jonathan K Merritt
- Vanderbilt Kennedy Center, Departments of Pediatrics, Pharmacology, and Special Education, Vanderbilt University Medical Center and Vanderbilt University, 1211 Medical Center Dr, Nashville, TN 37232, United States
| | - Katrina V Good
- Department of Biochemistry and Microbiology, University of Victoria, 3800 Finnerty Rd, Victoria, BC V8W 2Y2, Canada
- Molecular Neuropsychiatry & Development (MiND) Lab, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, 250 College St, Toronto, ON M5T 1R8, Canada
| | - Robert L Chow
- Department of Biology, University of Victoria, 3800 Finnerty Rd, Victoria, BC V8W 2Y2, Canada
| | - Kerry R Delaney
- Department of Biology, University of Victoria, 3800 Finnerty Rd, Victoria, BC V8W 2Y2, Canada
| | - Michael J Hendzel
- Departments of Oncology and Cell Biology, Faculty of Medicine and Dentistry, University of Alberta, 11560 University Ave, Edmonton, AB T6G 2H7, Canada
| | - Zhaolan Zhou
- Department of Genetics, Epigenetics Institute, University of Pennsylvania Perelman School of Medicine, 3400 Civic Center Blvd, Philadelphia, PA 19104, United States
| | - Jeffrey L Neul
- Vanderbilt Kennedy Center, Departments of Pediatrics, Pharmacology, and Special Education, Vanderbilt University Medical Center and Vanderbilt University, 1211 Medical Center Dr, Nashville, TN 37232, United States
| | - John B Vincent
- Molecular Neuropsychiatry & Development (MiND) Lab, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, 250 College St, Toronto, ON M5T 1R8, Canada
- Institute of Medical Science, University of Toronto, 27 King's College Cir, Toronto, ON M5S 1A8, Canada
- Department of Psychiatry, University of Toronto, 27 King College Cir, Toronto, ON M5T 1R8, Canada
| | - Juan Ausió
- Department of Biochemistry and Microbiology, University of Victoria, 3800 Finnerty Rd, Victoria, BC V8W 2Y2, Canada
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Cao Z, Min X, Xie X, Huang M, Liu Y, Sun W, Xu G, He M, He K, Li Y, Yuan J. RIPK1 activation in Mecp2-deficient microglia promotes inflammation and glutamate release in RTT. Proc Natl Acad Sci U S A 2024; 121:e2320383121. [PMID: 38289948 PMCID: PMC10861890 DOI: 10.1073/pnas.2320383121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Accepted: 12/27/2023] [Indexed: 02/01/2024] Open
Abstract
Rett syndrome (RTT) is a devastating neurodevelopmental disorder primarily caused by mutations in the methyl-CpG binding protein 2 (Mecp2) gene. Here, we found that inhibition of Receptor-Interacting Serine/Threonine-Protein Kinase 1 (RIPK1) kinase ameliorated progression of motor dysfunction after onset and prolonged the survival of Mecp2-null mice. Microglia were activated early in myeloid Mecp2-deficient mice, which was inhibited upon inactivation of RIPK1 kinase. RIPK1 inhibition in Mecp2-deficient microglia reduced oxidative stress, cytokines production and induction of SLC7A11, SLC38A1, and GLS, which mediate the release of glutamate. Mecp2-deficient microglia release high levels of glutamate to impair glutamate-mediated excitatory neurotransmission and promote increased levels of GluA1 and GluA2/3 proteins in vivo, which was reduced upon RIPK1 inhibition. Thus, activation of RIPK1 kinase in Mecp2-deficient microglia may be involved both in the onset and progression of RTT.
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Affiliation(s)
- Ze Cao
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai201203, China
- Shanghai Key Laboratory of Aging Studies, Shanghai201210, China
| | - Xia Min
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai201203, China
- University of Chinese Academy of Sciences, Beijing100049, China
| | - Xingxing Xie
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai201203, China
- University of Chinese Academy of Sciences, Beijing100049, China
| | - Maoqing Huang
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai201203, China
- University of Chinese Academy of Sciences, Beijing100049, China
| | - Yingying Liu
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai201203, China
- University of Chinese Academy of Sciences, Beijing100049, China
| | - Weimin Sun
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai201203, China
- Shanghai Key Laboratory of Aging Studies, Shanghai201210, China
- University of Chinese Academy of Sciences, Beijing100049, China
| | - Guifang Xu
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai201203, China
| | - Miao He
- Institutes of Brain Science, Department of Neurology, State Key Laboratory of Medical Neurobiology and Ministry of Education Frontiers Center for Brain Science, Zhongshan Hospital, Fudan University, Shanghai200032, China
| | - Kaiwen He
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai201203, China
- University of Chinese Academy of Sciences, Beijing100049, China
| | - Ying Li
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai201203, China
- Shanghai Key Laboratory of Aging Studies, Shanghai201210, China
- University of Chinese Academy of Sciences, Beijing100049, China
| | - Junying Yuan
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai201203, China
- Shanghai Key Laboratory of Aging Studies, Shanghai201210, China
- University of Chinese Academy of Sciences, Beijing100049, China
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