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MicroRNAs can generate thresholds in target gene expression.

ABSTRACT: MicroRNAs (miRNAs) are short, highly conserved noncoding RNA molecules that repress gene expression in a sequence-dependent manner. We performed single-cell measurements using quantitative fluorescence microscopy and flow cytometry to monitor a target gene's protein expression in the presence and absence of regulation by miRNA. We find that although the average level of repression is modest, in agreement with previous population-based measurements, the repression among individual cells varies dramatically. In particular, we show that regulation by miRNAs establishes a threshold level of target mRNA below which protein production is highly repressed. Near this threshold, protein expression responds sensitively to target mRNA input, consistent with a mathematical model of molecular titration. These results show that miRNAs can act both as a switch and as a fine-tuner of gene expression.

SUBMITTER: Mukherji S

PROVIDER: S-EPMC3163764 | biostudies-literature | 2011 Aug

REPOSITORIES: biostudies-literature

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MicroRNAs can generate thresholds in target gene expression.

Mukherji Shankar S Ebert Margaret S MS Zheng Grace X Y GX Tsang John S JS Sharp Phillip A PA van Oudenaarden Alexander A

Nature genetics 20110821 9

MicroRNAs (miRNAs) are short, highly conserved noncoding RNA molecules that repress gene expression in a sequence-dependent manner. We performed single-cell measurements using quantitative fluorescence microscopy and flow cytometry to monitor a target gene's protein expression in the presence and absence of regulation by miRNA. We find that although the average level of repression is modest, in agreement with previous population-based measurements, the repression among individual cells varies dr ...[more]

PMID: 21857679

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