M6A-facilitated hippocampal learning and memory through Ythdf1

ABSTRACT: N6-methyladenosine (m6A) is the most prevalent internal RNA modification in mammalian messenger RNAs (mRNAs). While m6A has been shown to mark groups of mRNAs for coordinated degradation in various physiological processes, the relevance of m6A in affecting translation remains to be determined in intact biological systems in vivo. Here we show that, through its reader protein Ythdf1, m6A promotes a pulse of protein synthesis of target transcripts in response to neuronal stimuli in the adult mouse hippocampus, thereby facilitating learning and memory processes. Mice with genetic deletion of the Ythdf1 gene (Ythdf1-/-) exhibit learning and memory defects, as well as impaired hippocampal synaptic transmission and long-term potentiation (LTP). Selective re-expression of Ythdf1 in the hippocampus of adult Ythdf1-/- mice fully rescues the behavioral and synaptic defects, while hippocampus-specific knockdown of Ythdf1 or Mettl3, the catalytic component of m6A methyltransferase complex, recapitulates the hippocampal deficiency in adult mice. At the molecular level, transcriptome-wide mapping of m6A sites and RNA binding sites of Ythdf1 on hippocampal mRNAs using crosslinking immunoprecipitation followed by high-throughput sequencing (CLIP-seq) uncovered key neuronal genes, including those involved in synaptic transmission and long-term potentiation. Nascent protein labelling and tether reporter assays in cultured hippocampal neurons revealed that Ythdf1 is critical for initiating a pulse of protein synthesis of target transcripts in a neuronal-stimulus-dependent manner. Collectively, our results uncover a pathway of mRNA m6A methylation in learning and memory, which is mediated through Ythdf1 in response to stimuli.

ORGANISM(S): Mus musculus

PROVIDER: GSE106607 | GEO | 2018/08/17

REPOSITORIES: GEO