| First Author | Poon VY | Year | 2016 |
| Journal | BMC Genomics | Volume | 17 |
| Issue | 1 | Pages | 777 |
| PubMed ID | 27716060 | Mgi Jnum | J:239334 |
| Mgi Id | MGI:5828341 | Doi | 10.1186/s12864-016-3139-7 |
| Citation | Poon VY, et al. (2016) miR-27b shapes the presynaptic transcriptome and influences neurotransmission by silencing the polycomb group protein Bmi1. BMC Genomics 17(1):777 |
| abstractText | BACKGROUND: MicroRNAs (miRNAs) are short non-coding RNAs that are emerging as important post-transcriptional regulators of neuronal and synaptic development. The precise impact of miRNAs on presynaptic function and neurotransmission remains, however, poorly understood. RESULTS: Here, we identify miR-27b-an abundant neuronal miRNA implicated in neurological disorders-as a global regulator of the presynaptic transcriptome. miR-27b influences the expression of three quarters of genes associated with presynaptic function in cortical neurons. Contrary to expectation, a large majority of these genes are up-regulated by miR-27b. This stimulatory effect is mediated by miR-27b-directed silencing of several transcriptional repressors that cooperate to suppress the presynaptic transcriptome. The strongest repressive activity appears to be mediated by Bmi1, a component of the polycomb repressive complex implicated in self-renewal of neural stem cells. miR-27b knockdown leads to reduced synaptogenesis and to a marked decrease in neural network activity, which is fully restored by RNAi-mediated silencing of Bmi1. CONCLUSIONS: We conclude that silencing of Bmi1 by miR-27b relieves repression of the presynaptic transcriptome and supports neurotransmission in cortical networks. These results expand the repressive activity of Bmi1 to genes involved in synaptic function and identify a unique post-transcriptional circuitry that stimulates expression of synaptic genes and promotes synapse differentiation. |
