How do microRNAs recognize their targets?
Sites with as little as seven base pairs matching the miRNA 5′ end can confer regulation; such 5′-dominant sites are common in conserved 3′ UTRs.
Source
Principles of microRNA-target recognition
What they did
Combined experimental and computational analyses of miRNA–target pairing rules in animals.
What they found
Seven-bp complementarity to the miRNA 5′ end suffices for in vivo regulation; genome-wide, 5′-dominant sites occur 2–3× more often than random in conserved 3′ UTRs and were often missed by energy-optimized predictors.
The limits
What it doesn't show
Rules are for animal miRNAs studied; not every predicted site is equally functional in every tissue.
Key terms
- microRNA (miRNA)
- Small noncoding RNA guiding post-transcriptional repression.
- Seed / 5′ site
- Short complementarity to the miRNA 5′ end.
- 3′ UTR
- Untranslated region harboring many miRNA sites.
- 5′-dominant site
- Target site relying mainly on 5′ pairing.
- Post-transcriptional regulation
- Control of mRNA stability/translation after transcription.
Flashcards
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Minimal highlighted pairing:
Common questions
Minimal pairing length highlighted?
Seven base pairs to the miRNA 5′ end.
Where are sites enriched?
Conserved 3′ UTRs.
Enrichment vs random?
About 2- to 3-fold.
Why missed before?
Limited pairing ranked poorly in energy-only searches.
More on Gene expression