MeCP2 Suppresses Nuclear MicroRNA Processing and Dendritic Growth by Regulating the DGCR8/Drosha Complex
TL;DR: It is reported that MeCP2 regulates gene expression posttranscriptionally by suppressing nuclear microRNA processing by binding directly to DiGeorge syndrome critical region 8 (DGCR8), a critical component of the nuclear micro RNA-processing machinery, and interferes with the assembly of Drosha and DG CR8 complex.
About: This article is published in Developmental Cell.The article was published on 2014-03-10 and is currently open access. It has received 220 citations till now. The article focuses on the topics: Drosha & Microprocessor complex.
Citations
More filters
TL;DR: Small non-coding RNAs that function as guide molecules in RNA silencing are involved in nearly all developmental and pathological processes in animals and their dysregulation is associated with many human diseases.
Abstract: MicroRNAs (miRNAs) are small non-coding RNAs that function as guide molecules in RNA silencing. Targeting most protein-coding transcripts, miRNAs are involved in nearly all developmental and pathological processes in animals. The biogenesis of miRNAs is under tight temporal and spatial control, and their dysregulation is associated with many human diseases, particularly cancer. In animals, miRNAs are ∼22 nucleotides in length, and they are produced by two RNase III proteins--Drosha and Dicer. miRNA biogenesis is regulated at multiple levels, including at the level of miRNA transcription; its processing by Drosha and Dicer in the nucleus and cytoplasm, respectively; its modification by RNA editing, RNA methylation, uridylation and adenylation; Argonaute loading; and RNA decay. Non-canonical pathways for miRNA biogenesis, including those that are independent of Drosha or Dicer, are also emerging.
4,256 citations
01 Jan 1993
TL;DR: In vitro footprinting indicates that MBD binding can protect a 12 nucleotide region surrounding a methyl-CpG pair, with an approximate dissociation constant of 10(-9) M.
Abstract: MeCP2isachromosomal protein whichbinds toDNA that ismethylated atCpG.Insitu immunofluorescence inmouse cells hasshownthattheprotein ismost concentrated inpericentromeric heterochromatin, suggesting that MeCP2mayplay arole intheformation ofInert chromatin. Herewe haveIsolated a minimal methyl-CpG binding domaln (MBD) fromMeCP2.MBD Is85aminoacids Inlength, andbindsexclusively to DNA thatcontains one or more symmetrically methylated CpGs.MBD hasnegligable non-specific affinity forDNA,confirming thatnon-specific and methyl-CpG specific binding domainsofMeCP2are distinct. Invitrofootprlnting Indicates thatMBDbinding can protect a 12nucleotide regionsurrounding a methyl-CpG pair, withan approximate dissociation constant of10-9M.
582 citations
TL;DR: Molecular insights are yielded into the critical functions of MeCP2 that promise to simplify the understanding of RTT pathology.
Abstract: Rett syndrome (RTT) is a severe neurological disorder caused by mutations in the X-linked gene MECP2 (methyl-CpG-binding protein 2). Two decades of research have fostered the view that MeCP2 is a multifunctional chromatin protein that integrates diverse aspects of neuronal biology. More recently, studies have focused on specific RTT-associated mutations within the protein. This work has yielded molecular insights into the critical functions of MeCP2 that promise to simplify our understanding of RTT pathology.
295 citations
TL;DR: The emerging role of epigenetics and epigenomics in DKD and the translational potential of candidate epigenetic factors and non-coding RNAs as biomarkers and drug targets for DKD are highlighted.
Abstract: The development and progression of diabetic kidney disease (DKD), a highly prevalent complication of diabetes mellitus, are influenced by both genetic and environmental factors. DKD is an important contributor to the morbidity of patients with diabetes mellitus, indicating a clear need for an improved understanding of disease aetiology to inform the development of more efficacious treatments. DKD is characterized by an accumulation of extracellular matrix, hypertrophy and fibrosis in kidney glomerular and tubular cells. Increasing evidence shows that genes associated with these features of DKD are regulated not only by classical signalling pathways but also by epigenetic mechanisms involving chromatin histone modifications, DNA methylation and non-coding RNAs. These mechanisms can respond to changes in the environment and, importantly, might mediate the persistent long-term expression of DKD-related genes and phenotypes induced by prior glycaemic exposure despite subsequent glycaemic control, a phenomenon called metabolic memory. Detection of epigenetic events during the early stages of DKD could be valuable for timely diagnosis and prompt treatment to prevent progression to end-stage renal disease. Identification of epigenetic signatures of DKD via epigenome-wide association studies might also inform precision medicine approaches. Here, we highlight the emerging role of epigenetics and epigenomics in DKD and the translational potential of candidate epigenetic factors and non-coding RNAs as biomarkers and drug targets for DKD. This Review describes the current understanding of the role of epigenetics and epigenomics in diabetic kidney disease (DKD) and how epigenetic mechanisms might contribute to metabolic memory. The authors also discuss how epigenetic factors and non-coding RNAs could be used as biomarkers and drug targets for DKD diagnosis, prognosis and treatment.
257 citations
TL;DR: It is reported that lentivirus-based transgenic cynomolgus monkeys (Macaca fascicularis) expressing human MeCP2 in the brain exhibit autism-like behaviours and show germline transmission of the transgene, indicating the feasibility and reliability of using genetically engineered non-human primates to study brain disorders.
Abstract: Methyl-CpG binding protein 2 (MeCP2) has crucial roles in transcriptional regulation and microRNA processing. Mutations in the MECP2 gene are found in 90% of patients with Rett syndrome, a severe developmental disorder with autistic phenotypes. Duplications of MECP2-containing genomic segments cause the MECP2 duplication syndrome, which shares core symptoms with autism spectrum disorders. Although Mecp2-null mice recapitulate most developmental and behavioural defects seen in patients with Rett syndrome, it has been difficult to identify autism-like behaviours in the mouse model of MeCP2 overexpression. Here we report that lentivirus-based transgenic cynomolgus monkeys (Macaca fascicularis) expressing human MeCP2 in the brain exhibit autism-like behaviours and show germline transmission of the transgene. Expression of the MECP2 transgene was confirmed by western blotting and immunostaining of brain tissues of transgenic monkeys. Genomic integration sites of the transgenes were characterized by a deep-sequencing-based method. As compared to wild-type monkeys, MECP2 transgenic monkeys exhibited a higher frequency of repetitive circular locomotion and increased stress responses, as measured by the threat-related anxiety and defensive test. The transgenic monkeys showed less interaction with wild-type monkeys within the same group, and also a reduced interaction time when paired with other transgenic monkeys in social interaction tests. The cognitive functions of the transgenic monkeys were largely normal in the Wisconsin general test apparatus, although some showed signs of stereotypic cognitive behaviours. Notably, we succeeded in generating five F1 offspring of MECP2 transgenic monkeys by intracytoplasmic sperm injection with sperm from one F0 transgenic monkey, showing germline transmission and Mendelian segregation of several MECP2 transgenes in the F1 progeny. Moreover, F1 transgenic monkeys also showed reduced social interactions when tested in pairs, as compared to wild-type monkeys of similar age. Together, these results indicate the feasibility and reliability of using genetically engineered non-human primates to study brain disorders.
241 citations
References
More filters
TL;DR: Although they escaped notice until relatively recently, miRNAs comprise one of the more abundant classes of gene regulatory molecules in multicellular organisms and likely influence the output of many protein-coding genes.
32,946 citations
"MeCP2 Suppresses Nuclear MicroRNA P..." refers background in this paper
..., microRNAs (miRNAs), which are known to specifically suppress generation of many proteins that are important for cell proliferation, development, and tumorigenesis (Bartel, 2004; Bushati and Cohen, 2007; Fire et al., 1998)....
[...]
...…possibility is that MeCP2 controls posttranscriptional regulators, e.g., microRNAs (miRNAs), which are known to specifically suppress generation of many proteins that are important for cell proliferation, development, and tumorigenesis (Bartel, 2004; Bushati and Cohen, 2007; Fire et al., 1998)....
[...]
TL;DR: To their surprise, it was found that double-stranded RNA was substantially more effective at producing interference than was either strand individually, arguing against stochiometric interference with endogenous mRNA and suggesting that there could be a catalytic or amplification component in the interference process.
Abstract: Experimental introduction of RNA into cells can be used in certain biological systems to interfere with the function of an endogenous gene Such effects have been proposed to result from a simple antisense mechanism that depends on hybridization between the injected RNA and endogenous messenger RNA transcripts RNA interference has been used in the nematode Caenorhabditis elegans to manipulate gene expression Here we investigate the requirements for structure and delivery of the interfering RNA To our surprise, we found that double-stranded RNA was substantially more effective at producing interference than was either strand individually After injection into adult animals, purified single strands had at most a modest effect, whereas double-stranded mixtures caused potent and specific interference The effects of this interference were evident in both the injected animals and their progeny Only a few molecules of injected double-stranded RNA were required per affected cell, arguing against stochiometric interference with endogenous mRNA and suggesting that there could be a catalytic or amplification component in the interference process
15,374 citations
"MeCP2 Suppresses Nuclear MicroRNA P..." refers background in this paper
..., microRNAs (miRNAs), which are known to specifically suppress generation of many proteins that are important for cell proliferation, development, and tumorigenesis (Bartel, 2004; Bushati and Cohen, 2007; Fire et al., 1998)....
[...]
...…possibility is that MeCP2 controls posttranscriptional regulators, e.g., microRNAs (miRNAs), which are known to specifically suppress generation of many proteins that are important for cell proliferation, development, and tumorigenesis (Bartel, 2004; Bushati and Cohen, 2007; Fire et al., 1998)....
[...]
TL;DR: The two RNase III proteins, Drosha and Dicer, may collaborate in the stepwise processing of miRNAs, and have key roles in miRNA-mediated gene regulation in processes such as development and differentiation.
Abstract: Hundreds of small RNAs of approximately 22 nucleotides, collectively named microRNAs (miRNAs), have been discovered recently in animals and plants. Although their functions are being unravelled, their mechanism of biogenesis remains poorly understood. miRNAs are transcribed as long primary transcripts (pri-miRNAs) whose maturation occurs through sequential processing events: the nuclear processing of the pri-miRNAs into stem-loop precursors of approximately 70 nucleotides (pre-miRNAs), and the cytoplasmic processing of pre-miRNAs into mature miRNAs. Dicer, a member of the RNase III superfamily of bidentate nucleases, mediates the latter step, whereas the processing enzyme for the former step is unknown. Here we identify another RNase III, human Drosha, as the core nuclease that executes the initiation step of miRNA processing in the nucleus. Immunopurified Drosha cleaved pri-miRNA to release pre-miRNA in vitro. Furthermore, RNA interference of Drosha resulted in the strong accumulation of pri-miRNA and the reduction of pre-miRNA and mature miRNA in vivo. Thus, the two RNase III proteins, Drosha and Dicer, may collaborate in the stepwise processing of miRNAs, and have key roles in miRNA-mediated gene regulation in processes such as development and differentiation.
5,191 citations
"MeCP2 Suppresses Nuclear MicroRNA P..." refers background in this paper
...The biogenesis of miRNAs begins with the transcription of the primary miRNAs from the genome, followed by its processing through Drosha/DiGeorge syndrome critical region 8 (DGCR8)containing nuclearmachinery and cytosolic Dicer complex (Denli et al., 2004; Gregory et al., 2004; Han et al., 2004; Lee et al., 2003)....
[...]
...…of miRNAs begins with the transcription of the primary miRNAs from the genome, followed by its processing through Drosha/DiGeorge syndrome critical region 8 (DGCR8)containing nuclearmachinery and cytosolic Dicer complex (Denli et al., 2004; Gregory et al., 2004; Han et al., 2004; Lee et al., 2003)....
[...]
TL;DR: This study reports the first disease-causing mutations in RTT and points to abnormal epigenetic regulation as the mechanism underlying the pathogenesis of RTT.
Abstract: Rett syndrome (RTT, MIM 312750) is a progressive neurodevelopmental disorder and one of the most common causes of mental retardation in females, with an incidence of 1 in 10,000-15,000 (ref. 2). Patients with classic RTT appear to develop normally until 6-18 months of age, then gradually lose speech and purposeful hand use, and develop microcephaly, seizures, autism, ataxia, intermittent hyperventilation and stereotypic hand movements. After initial regression, the condition stabilizes and patients usually survive into adulthood. As RTT occurs almost exclusively in females, it has been proposed that RTT is caused by an X-linked dominant mutation with lethality in hemizygous males. Previous exclusion mapping studies using RTT families mapped the locus to Xq28 (refs 6,9,10,11). Using a systematic gene screening approach, we have identified mutations in the gene (MECP2 ) encoding X-linked methyl-CpG-binding protein 2 (MeCP2) as the cause of some cases of RTT. MeCP2 selectively binds CpG dinucleotides in the mammalian genome and mediates transcriptional repression through interaction with histone deacetylase and the corepressor SIN3A (refs 12,13). In 5 of 21 sporadic patients, we found 3 de novo missense mutations in the region encoding the highly conserved methyl-binding domain (MBD) as well as a de novo frameshift and a de novo nonsense mutation, both of which disrupt the transcription repression domain (TRD). In two affected half-sisters of a RTT family, we found segregation of an additional missense mutation not detected in their obligate carrier mother. This suggests that the mother is a germline mosaic for this mutation. Our study reports the first disease-causing mutations in RTT and points to abnormal epigenetic regulation as the mechanism underlying the pathogenesis of RTT.
4,503 citations
"MeCP2 Suppresses Nuclear MicroRNA P..." refers background in this paper
...Loss-of-function mutations of MECP2 lead to RTT, whereas duplication of MECP2-containing locus leads to autism spectrum disorders....
[...]
...Frame-shifting and truncated mutations around amino acid 380, which led to a deletion of 100 aa from the C terminus, are frequently identified mutations pmental Cell 28, 547–560, March 10, 2014 ª2014 Elsevier Inc. 549 in patients with RTT (Bebbington et al., 2010)....
[...]
...Our finding of a posttranscriptional function of MeCP2 in regulating miRNA maturation suggests that intervening dysregulated miRNA processing represents a potential therapeutic approach in the treatment of RTT....
[...]
...The C-terminal deletions accounted for 15% of all genetic mutations identified among the patients with RTT (Bebbington et al., 2010)....
[...]
...Loss- and gain-of-function mutations of the X-linked gene MECP2 (methyl-CpG binding protein 2) lead to severe neurodevelopmental disorders in humans, such as Rett syndrome (RTT) and autism....
[...]
TL;DR: The data suggest that two global mechanisms of gene regulation, DNA methylation and histone deacetylation, can be linked by MeCP2, an abundant nuclear protein that is essential for mouse embryogenesis.
Abstract: Cytosine residues in the sequence 5'CpG (cytosine-guanine) are often postsynthetically methylated in animal genomes. CpG methylation is involved in long-term silencing of certain genes during mammalian development and in repression of viral genomes. The methyl-CpG-binding proteins MeCP1 and MeCP2 interact specifically with methylated DNA and mediate transcriptional repression. Here we study the mechanism of repression by MeCP2, an abundant nuclear protein that is essential for mouse embryogenesis. MeCP2 binds tightly to chromosomes in a methylation-dependent manner. It contains a transcriptional-repression domain (TRD) that can function at a distance in vitro and in vivo. We show that a region of MeCP2 that localizes with the TRD associates with a corepressor complex containing the transcriptional repressor mSin3A and histone deacetylases. Transcriptional repression in vivo is relieved by the deacetylase inhibitor trichostatin A, indicating that deacetylation of histones (and/or of other proteins) is an essential component of this repression mechanism. The data suggest that two global mechanisms of gene regulation, DNA methylation and histone deacetylation, can be linked by MeCP2.
3,396 citations
"MeCP2 Suppresses Nuclear MicroRNA P..." refers background in this paper
...…nuclear protein, MeCP2 could not only repress gene transcription by binding to methylated DNA 556 Developmental Cell 28, 547–560, March 10, 2014 ª2014 Elsevier and recruiting transcriptional repressors (Nan et al., 1998) but also suppress miRNA processing by binding to RNA-binding domains of DGCR8....
[...]
...MeCP2 was found to primarily bind to methylated CpG islands and acts as a transcriptional repressor by recruiting histone deacetylase complex (HDAC) (Lewis et al., 1992; Nan et al., 1993, 1998; reviewed in Guy et al., 2011)....
[...]