miRNA binding

Definition

Target type: molecularfunction

Binding to a microRNA, a 21-23 nucleotide RNA that is processed from a stem-loop RNA precursor (pre-miRNA) that is encoded within plant and animal genomes. [PMID:15066283]

MicroRNAs (miRNAs) are small, non-coding RNA molecules that play a critical role in regulating gene expression. They exert their regulatory function primarily by binding to specific target messenger RNA (mRNA) molecules, typically in the 3' untranslated region (3'UTR), leading to post-transcriptional gene silencing. This binding event can occur through complementary base pairing between the miRNA and the mRNA sequence, resulting in various outcomes:

1. **mRNA Degradation:** Binding of the miRNA to the mRNA can trigger the recruitment of the RNA-induced silencing complex (RISC), which contains proteins like Argonaute. This complex can then degrade the target mRNA, preventing its translation into a protein.

2. **Translation Inhibition:** Even if the mRNA is not degraded, the miRNA-mRNA interaction can hinder ribosome recruitment and prevent the mRNA from being translated into a protein.

3. **mRNA Storage:** In certain cases, miRNA binding might lead to the sequestration of the mRNA in processing bodies (P-bodies) or other cellular compartments, effectively preventing its translation.

4. **Epigenetic Modifications:** Recent evidence suggests that miRNAs can also induce epigenetic modifications, such as histone modifications, affecting gene expression at the chromatin level.

The specific molecular function of miRNA binding depends on various factors:

* **Seed Sequence:** The miRNA's seed sequence, a 6-8 nucleotide region at the 5' end, is crucial for target recognition. This seed sequence has a high affinity for the target mRNA and is often perfectly complementary.

* **Target Site Accessibility:** The accessibility of the target site within the mRNA can influence miRNA binding efficiency. Secondary structures within the mRNA, such as stem-loops, can hinder miRNA binding.

* **Cellular Context:** The cellular context, including the presence of specific proteins and other regulatory molecules, can influence miRNA-mRNA interactions.

The regulation of gene expression by miRNAs is highly dynamic and complex. These small molecules play a crucial role in various biological processes, including development, differentiation, cell growth, and disease pathogenesis.'
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Proteins (4)

Compounds (10)