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A Single Let-7 MicroRNA Bypasses LIN28-Mediated Repression

Overview
Journal Cell Rep
Publisher Cell Press
Date 2015 Oct 7
PMID 26440890
Citations 30
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Abstract

Let-7 microRNAs (miRNAs) are critical regulators of animal development, stem cell differentiation, glucose metabolism, and tumorigenesis. Mammalian genomes contain 12 let-7 isoforms that suppress expression of a common set of target mRNAs. LIN28 proteins selectively block let-7 biogenesis in undifferentiated cells and in cancer. The current model for coordinate let-7 repression involves the LIN28 cold-shock domain (CSD) binding the terminal loop and the two CCHC-type zinc fingers recognizing a GGAG sequence motif in precursor let-7 (pre-let-7) RNAs. Here, we perform a systematic analysis of all let-7 miRNAs and find that a single let-7 family member, human let-7a-3 (and its murine ortholog let-7c-2), escapes LIN28-mediated regulation. Mechanistically, we find that the pre-let-7c-2 loop precludes LIN28A binding and regulation. These findings refine the current model of let-7 regulation by LIN28 proteins and have important implications for understanding the LIN28/let-7 axis in development and disease.

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References
1.
Reinhart B, Slack F, Basson M, Pasquinelli A, Bettinger J, Rougvie A . The 21-nucleotide let-7 RNA regulates developmental timing in Caenorhabditis elegans. Nature. 2000; 403(6772):901-6. DOI: 10.1038/35002607. View

2.
Pasquinelli A, Reinhart B, Slack F, Martindale M, Kuroda M, Maller B . Conservation of the sequence and temporal expression of let-7 heterochronic regulatory RNA. Nature. 2000; 408(6808):86-9. DOI: 10.1038/35040556. View

3.
Moss E, Tang L . Conservation of the heterochronic regulator Lin-28, its developmental expression and microRNA complementary sites. Dev Biol. 2003; 258(2):432-42. DOI: 10.1016/s0012-1606(03)00126-x. View

4.
Ambros V, Horvitz H . Heterochronic mutants of the nematode Caenorhabditis elegans. Science. 1984; 226(4673):409-16. DOI: 10.1126/science.6494891. View

5.
Moss E, Lee R, Ambros V . The cold shock domain protein LIN-28 controls developmental timing in C. elegans and is regulated by the lin-4 RNA. Cell. 1997; 88(5):637-46. DOI: 10.1016/s0092-8674(00)81906-6. View