International Journal of Genomics

Review Article

Mechanisms of miRNA-Mediated Gene Regulation from Common Downregulation to mRNA-Specific Upregulation

Table 2

Examples of relief from miRNA-mediated downregulation.


miRNA	Target mRNA	Expression regulation	Reference

miR-122	CAT-1	In response to amino acid starvation, HuR binding to 3′UTR interferes with miRNP association with CAT-1 mRNA and results in relocalization of mRNP from P bodies in the cytoplasm to polysomes.	[105, 110]
miR-134	LIMK1	In response to extracellular stimuli, HuR binds to LIMK1 mRNA in the dendritic spines and alleviates miRNA-mediated repression.	[166, 167]
miR-19	RhoB	The loss of the interdependent binding between HuR and miR-19 to the RhoB mRNA upon UV exposure relieves this mRNA from miR-19-dependent inhibition of translation.	[168]
miR-548c-3p	TOP2A	HuR enhances TOP2A translation by antagonizing with miR-548c-3p. Their combined actions control TOP2A expression levels and determine the effectiveness of doxorubicin.	[169]
miR-430	Nanos1 and TDRD7	DND1 prevents miRNA-mediated downregulation in primordial germ cells by blocking miRNP access to 3′UTR of target mRNAs.	[154]
miR-221 and miR-222	P27KIP1	In arrested cells, Pum1 is unable to bind to 3′UTR of target mRNA and cannot open its loop structure and therefore restricts miRNA binding.	[154]
miR-19b	PTEN	PTEN1 (a pseudogene) acts as a decoy factor for miRNAs and derepresses PTENs expression.	[170]
miR-20a	KRAS	KRAS1P sequesters miRNA and promotes expression of KRAS.	[170]
miR-166/165	Homeodomain leucine zipper transcript factor	AGO10 acts as a sponge to decoy away miRNAs from AGO1 bearing miRNPs.	[164]
miR-184 and let-7	LRRK2	Gain of function mutation in LRRK2 makes it more associable to dAGO1 and LRRK2 kinase which phosphorylates 4E-BP1 and consequently associates with hAGO2 which counteracts with miRNA mediated repression.	[171, 172]
miR-26a/b	IL-6	3′-end uridylation of miRNAs relieves their miRNA-mediated repression and promotes IL-6 expression.	[173]
miR-485-5p	BACE1	BACE1-AS (a lncRNA) binds to BACE1 mRNA in its seed site and prevents miRNP binding to their target mRNAs.	[158]
miR-145	OCT4, SOX2, and NANOG	In the presence of Linc-ROR (a lncRNA), miR-145 is trapped and consequently decoyed away from its target mRNAs.	[159–162]