Loss of O-GlcNAcylation on MeCP2 at Threonine 203 Leads to Neurodevelopmental Disorders / 神经科学通报·英文版

Mutations of the X-linked methyl-CpG-binding protein 2 (MECP2) gene in humans are responsible for most cases of Rett syndrome (RTT), an X-linked progressive neurological disorder. While genome-wide screens in clinical trials have revealed several putative RTT-associated mutations in MECP2, their causal relevance regarding the functional regulation of MeCP2 at the etiologic sites at the protein level requires more evidence. In this study, we demonstrated that MeCP2 was dynamically modified by O-linked-β-N-acetylglucosamine (O-GlcNAc) at threonine 203 (T203), an etiologic site in RTT patients. Disruption of the O-GlcNAcylation of MeCP2 specifically at T203 impaired dendrite development and spine maturation in cultured hippocampal neurons, and disrupted neuronal migration, dendritic spine morphogenesis, and caused dysfunction of synaptic transmission in the developing and juvenile mouse cerebral cortex. Mechanistically, genetic disruption of O-GlcNAcylation at T203 on MeCP2 decreased the neuronal activity-induced induction of Bdnf transcription. Our study highlights the critical role of MeCP2 T203 O-GlcNAcylation in neural development and synaptic transmission potentially via brain-derived neurotrophic factor.

Differential proteomic analysis of transgenic Bt rice and its non-transgenic parental rice / 国际药学研究杂志

Objective Under the methodology of differential proteomics and bioinformatics,the impact of the exogenous gene on the expression of rice in the proteome is discussed,aiming to explore into the study of genetically modified rice in the proteomics. Methods The total protein was extracted from genetically modified rice Huahui No.1(HH1) and non-transgenic rice Minghui 63 (MH63),the method of two-dimensional gel electrophoresis was applied to generate corresponding proteome two-dimensional poly?acrylamide gel(2D-PAGE)electrophoresis spectrum;then,the mass spectrometry and bioinformatics analysis were conducted after the selection of protein spots with significant differences. Results The comparing and matching of protein spots between transgenic Bt (cry1Ab/1Ac)rice and non-transgenic rice 2D-PAGE profiles identified 28 protein spots with significant differences. With non-trans?genic rice as a reference,transgenic Bt rice held 18 relatively high and 10 relatively low expressions;mass spectrometry and bioinfor?matics retrieval were made on the different protein spots. It was found that the differentiated protein was mainly involved in energy me?tabolism,protein synthesis,redox stress response and other biological processes. Conclusion Differences exist between transgenic Bt HH1 and its parental rice MH63 on the expression of proteome;however,there are neither anti-nutritional and allergenic protein, nor new or toxic proteins among these differentiated proteins.