Synaptic enrichment of microRNAs in adult mouse forebrain is related to structural features of their precursors.

Department of Psychiatry and Psychiatric Institute, MC912, University of Illinois at Chicago, 1601 W, Taylor Street, Chicago, IL 60612, USA. neils@uic.edu

Within mouse forebrain, a subset of microRNAs are significantly enriched in synaptoneurosomes (a synaptic fraction containing pinched-off dendritic spines) and a subset are significantly depleted relative to total forebrain homogenate. Here I show that, as a group, the pre-miR hairpin precursors of synaptically enriched microRNAs exhibit significantly different structural features than those that are non-enriched or depleted. Precursors of synaptically enriched microRNAs tend to have a) shorter uninterrupted double-stranded stem segments, and b) more symmetrical bulges containing a single nucleotide on each side. These structural differences may provide a basis for the differential binding of proteins that mediate dendritic transport of pre-miRs, or that prevent pre-miRs from being prematurely processed into mature miRNAs during the transport process. Reviewers: This article was reviewed by I. King Jordan and Jerzy Jurka.

PMID: 18957138 [PubMed - indexed for MEDLINE]

PMCID: PMC2588566