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. 2003 Jun;132(2):709-17.
doi: 10.1104/pp.103.023630.

MicroRNAs: at the root of plant development?

Bonnie Bartel  1 , David P Bartel
Affiliations

MicroRNAs: at the root of plant development?

Bonnie Bartel et al. Plant Physiol. 2003 Jun.
No abstract available

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Figures

Figure 1.
Figure 1.
Current models for the biogenesis and possible roles of miRNAs and siRNAs. See text for references. A, The portion of the primary transcript that contains the miRNA sequence (red) resides on one arm of a predicted stem-loop precursor structure. The transcription start and stop sites for miRNA primary transcripts have not yet been defined. In animals, the hairpin precursor (in brackets) is processed from the primary transcript, but such intermediates have not been detected in plants. Either the primary transcript or this processed hairpin is cleaved by Dicer to yield paired approximately 21-nt RNAs with 2-nt 3′ overhangs, 5′ phosphates, and 3′ hydroxyls. One strand of this short-lived double-stranded intermediate accumulates as the mature miRNA (in red), which acts as a guide RNA within the miRNP/RISC complex. B, Long dsRNA is processed into many different siRNA species. siRNAs from both strands of the precursor accumulate within RISC complexes. C, The near perfect pairing between many plant miRNAs and their mRNA targets directs the RISC to cleave the target near the center of the complementarity site. This is also the classical mode of action for siRNAs during RNAi. D, Characterized animal miRNAs appear to recognize multiple sites in the 3′-untranslated region (UTR) of target mRNAs. Because they bind to their targets with numerous mismatches, the miRNP/RISC does not cleave the message. Although the message levels remain constant, protein levels decrease, perhaps from translational attenuation. Whether any plant miRNAs act via this mechanism is not known. E, Some endogenous siRNAs, known as heterochromatic siRNAs, are thought to direct histone methylation, which is correlated with transcriptional silencing of the modified regions. Many of the non-miRNA small RNAs that have been cloned from Arabidopsis might act similarly.
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References

    1. Aida M, Ishida T, Fukaki H, Fujisawa H, Tasaka M (1997) Genes involved in organ separation in Arabidopsis: an analysis of the cup-shaped cotyledon mutant. Plant Cell 9: 841–857 - PMC - PubMed
    1. Allshire R (2002) RNAi and heterochromatin: a hushed-up affair. Science 297: 1818–1819 - PubMed
    1. Ambros V, Bartel B, Bartel DP, Burge CB, Carrington JC, Chen X, Dreyfuss G, Eddy S, Griffiths-Jones S, Marshall M et al. (2003) A uniform system for microRNA annotation. RNA 9: 277–279 - PMC - PubMed
    1. Bohmert K, Camus I, Bellini C, Bouchez D, Caboche M, Benning C (1998) AGO1 defines a novel locus of Arabidopsis controlling leaf development. EMBO J 17: 170–180 - PMC - PubMed
    1. Bowman JL, Smyth DR, Meyerowitz EM (1989) Genes directing flower development in Arabidopsis. Plant Cell 1: 37–52 - PMC - PubMed

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