MicroRNA (miRNA) are small, single-stranded, non-coding RNA molecules containing 21 to 23 nucleotides. Found in plants, animals and some viruses, miRNAs are involved in RNA silencing and post-transcriptional regulation of gene expression. miRNAs base-pair to complementary sequences in mRNA molecules, then silence said mRNA molecules by one or more of the following processes:
- Cleavage of the mRNA strand into two pieces,
- Destabilization of the mRNA by shortening its poly(A) tail, or
- Reducing translation of the mRNA into proteins.
In molecular biology, miR-148 is a microRNA whose expression has been demonstrated in human, mouse, rat and zebrafish. miR-148 has also been predicted in chicken.
The mir-10 microRNA precursor is a short non-coding RNA gene involved in gene regulation. It is part of an RNA gene family which contains mir-10, mir-51, mir-57, mir-99 and mir-100. mir-10, mir-99 and mir-100 have now been predicted or experimentally confirmed in a wide range of species. miR-51 and miR-57 have currently only been identified in the nematode Caenorhabditis elegans.
In molecular biology miR-181 microRNA precursor is a small non-coding RNA molecule. MicroRNAs (miRNAs) are transcribed as ~70 nucleotide precursors and subsequently processed by the RNase-III type enzyme Dicer to give a ~22 nucleotide mature product. In this case the mature sequence comes from the 5' arm of the precursor. They target and modulate protein expression by inhibiting translation and / or inducing degradation of target messenger RNAs. This new class of genes has recently been shown to play a central role in malignant transformation. miRNA are downregulated in many tumors and thus appear to function as tumor suppressor genes. The mature products miR-181a, miR-181b, miR-181c or miR-181d are thought to have regulatory roles at posttranscriptional level, through complementarity to target mRNAs. miR-181 has been predicted or experimentally confirmed in a wide number of vertebrate species such as rat, zebrafish, and pufferfish.
The miR-24 microRNA precursor is a small non-coding RNA molecule that regulates gene expression. microRNAs are transcribed as ~70 nucleotide precursors and subsequently processed by the Dicer enzyme to give a mature ~22 nucleotide product. In this case the mature sequence comes from the 3' arm of the precursor. The mature products are thought to have regulatory roles through complementarity to mRNA. miR-24 is conserved in various species, and is clustered with miR-23 and miR-27, on human chromosome 9 and 19. Recently, miR-24 has been shown to suppress expression of two crucial cell cycle control genes, E2F2 and Myc in hematopoietic differentiation and also to promote keratinocyte differentiation by repressing actin-cytoskeleton regulators PAK4, Tsk5 and ArhGAP19.
This family represents the microRNA (miRNA) precursor mir-7. This miRNA has been predicted or experimentally confirmed in a wide range of species. miRNAs are transcribed as ~70 nucleotide precursors and subsequently processed by the Dicer enzyme to give a ~22 nucleotide product. In this case the mature sequence comes from the 5' arm of the precursor. The extents of the hairpin precursors are not generally known and are estimated based on hairpin prediction. The involvement of Dicer in miRNA processing suggests a relationship with the phenomenon of RNA interference.
microRNA 21 also known as hsa-mir-21 or miRNA21 is a mammalian microRNA that is encoded by the MIR21 gene.
MiR-155 is a microRNA that in humans is encoded by the MIR155 host gene or MIR155HG. MiR-155 plays a role in various physiological and pathological processes. Exogenous molecular control in vivo of miR-155 expression may inhibit malignant growth, viral infections, and enhance the progression of cardiovascular diseases.
In molecular biology, mir-145 microRNA is a short RNA molecule that in humans is encoded by the MIR145 gene. MicroRNAs function to regulate the expression levels of other genes by several mechanisms.
MicroRNA 187 is a protein that in humans is encoded by the MIR187 gene.
MicroRNA 196a-2 is a MicroRNA that in humans is encoded by the MIR196A2 gene, and is part of the Mir-196 microRNA precursor family.
The microprocessor complex is a protein complex involved in the early stages of processing microRNA (miRNA) and RNA interference (RNAi) in animal cells. The complex is minimally composed of the ribonuclease enzyme Drosha and the dimeric RNA-binding protein DGCR8, and cleaves primary miRNA substrates to pre-miRNA in the cell nucleus. Microprocessor is also the smaller of the two multi-protein complexes that contain human Drosha.
MicroRNA 138-1 is a protein that in humans is encoded by the MIR138-1 gene.
MicroRNA 203a is a small RNA that in humans is encoded by the preMIR203A gene.
MicroRNA 148a is a miRNA that in humans is encoded by the MIR148A gene.
MicroRNA 494 is a microRNA sequence which is encoded in humans by the MIR494 gene.
MicroRNA 106a is a microRNA that in humans is encoded by the MIR106A gene.
MicroRNA 495 is a protein that in humans is encoded by the MIR495 gene.
MicroRNA 141 is a non-coding RNA molecule that in humans is encoded by the MIR141 gene.
MicroRNA 210 is a protein that in humans is encoded by the MIR210 gene.
