MicroRNA-92a is a circadian modulator of neuronal excitability in Drosophila.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 28276426.
- Also identified by DOI 10.1038/ncomms14707 and PMC identifier 5347142.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Many biological and behavioural processes of animals are governed by an endogenous circadian clock, which is dependent on transcriptional regulation. Here we address post-transcriptional regulation and the role of miRNAs in Drosophila circadian rhythms. At least six miRNAs show cycling expression levels within the pigment dispersing factor (PDF) cell-pacemaker neurons; only mir-92a peaks during the night. In vivo calcium monitoring, dynamics of PDF projections, ArcLight, GCaMP6 imaging and sleep assays indicate that mir-92a suppresses neuronal excitability. In addition, mir-92a levels within PDF cells respond to light pulses and also affect the phase shift response. Translating ribosome affinity purification (TRAP) and in vitro luciferase reporter assay indicate that mir-92a suppresses expression of sirt2, which is homologous to human sir2 and sirt3. sirt2 RNAi also phenocopies mir-92a overexpression. These experiments indicate that sirt2 is a functional mir-92a target and that mir-92a modulates PDF neuronal excitability via suppressing SIRT2 levels in a rhythmic manner.
Medical subject headings
- Circadian Clocks
- Circadian Rhythm
- Gene Expression Regulation
- MicroRNAs
- Neurons