Mir-7 microRNA precursor

Last updated
mir-7 microRNA precursor
RF00053.jpg
Predicted secondary structure and sequence conservation of mir-7
Identifiers
Symbolmir-7
Rfam RF00053
miRBase MI0000263
miRBase family MIPF0000022
Other data
RNA type Gene; miRNA
Domain(s) Eukaryota
GO GO:0035195 GO:0035068
SO SO:0001244
PDB structures PDBe

This family represents the microRNA (miRNA) precursor mir-7. This miRNA has been predicted or experimentally confirmed in a wide range of species. [1] miRNAs are transcribed as ~70 nucleotide precursors (modelled here) 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.

Contents

Mature miRNA-7 is derived from three microRNA precursors in the human genome, miR-7-1, miR-7-2 and miR-7-3. miRNAs are numbered based on the sequence of the mature RNA.

miR-7 is directly regulated by the transcription factor HoxD10. [2]

miRNAs are thought to have regulatory roles through complementarity to mRNA. miR-7 is essential for the maintenance of regulatory stability under conditions of environmental flux. [3] It plays an important role in controlling mRNA expression. The miR-7 gene is found in most sequenced Urbilateria species, and the sequence of its mature miRNA product is perfectly conserved from annelids to humans, indicating a strong functional conservation. [3]

Targets of miR-7

Bioinformatic predictions suggest that the human EGFR mRNA 3'-untranslated region contains three microRNA-7 (miR-7) target sites, which are not conserved across mammals. [4] In Drosophila photoreceptor cells, miR-7 controls epidermal growth factor receptor (EGFR) signaling and promotes photoreceptor differentiation. [5] Among other targets of miR-7 are insulin-like growth factor 1 receptor (IGF1R) and PIK3CD, [6] E(spl) gene family [7] and Pak1 (cancer cells). [2] c-Fos is also a target of miR-7b in mice. [8] Pax6 translation in the lateral wall of the subventricular zone of developed mice is post-transcriptionally regulated by miRNA-7a mediated gene silencing, which is necessary to control the rate of dopaminergic neuron production in the olfactory bulb. [9]

Clinical relevance

Multiple roles and targets of miR-7 as well as its expression pattern were linked to regulatory mechanisms and pathogenesis in glioblastoma, [10] breast cancer [11] and other types of cancers, [4] [6] [12] as well as in schizophrenia [13] and visual abnormalities. [14] Inhibition of the motility, invasiveness, anchorage-independent growth, and tumorigenic potential of highly invasive breast cancer cells through the introduction of miR-7 suggests a strong therapeutic potential of miR-7. [2] [15]

Related Research Articles

The Let-7 microRNA precursor was identified from a study of developmental timing in C. elegans, and was later shown to be part of a much larger class of non-coding RNAs termed microRNAs. miR-98 microRNA precursor from human is a let-7 family member. Let-7 miRNAs have now been predicted or experimentally confirmed in a wide range of species (MIPF0000002). miRNAs are initially transcribed in long transcripts called primary miRNAs (pri-miRNAs), which are processed in the nucleus by Drosha and Pasha to hairpin structures of about 70 nucleotide. These precursors (pre-miRNAs) are exported to the cytoplasm by exportin5, where they are subsequently processed by the enzyme Dicer to a ~22 nucleotide mature miRNA. The involvement of Dicer in miRNA processing demonstrates a relationship with the phenomenon of RNA interference.

mir-8/mir-141/mir-200 microRNA precursor family

The miR-8 microRNA precursor, is a short non-coding RNA gene involved in gene regulation. miR-8 in Drosophila melanogaster is expressed from the 3' arm of related precursor hairpins, along with miR-200, miR-236, miR-429 and human and mouse homolog miR-141. Members of this precursor family have now been predicted or experimentally confirmed in a wide range of species. The bounds of the precursors are predicted based on conservation and base pairing and are not generally known.

mir-9/mir-79 microRNA precursor family

The miR-9 microRNA, is a short non-coding RNA gene involved in gene regulation. The mature ~21nt miRNAs are processed from hairpin precursor sequences by the Dicer enzyme. The dominant mature miRNA sequence is processed from the 5' arm of the mir-9 precursor, and from the 3' arm of the mir-79 precursor. The mature products are thought to have regulatory roles through complementarity to mRNA. In vertebrates, miR-9 is highly expressed in the brain, and is suggested to regulate neuronal differentiation. A number of specific targets of miR-9 have been proposed, including the transcription factor REST and its partner CoREST.

mir-10 microRNA precursor family Short non-coding RNA gene

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.

mir-19 microRNA precursor family

There are 89 known sequences today in the microRNA 19 (miR-19) family but it will change quickly. They are found in a large number of vertebrate species. The miR-19 microRNA precursor is a small non-coding RNA molecule that regulates gene expression. Within the human and mouse genome there are three copies of this microRNA that are processed from multiple predicted precursor hairpins:

mir-1 microRNA precursor family

The miR-1 microRNA precursor is a small micro RNA that regulates its target protein's expression in the cell. microRNAs are transcribed as ~70 nucleotide precursors and subsequently processed by the Dicer enzyme to give products at ~22 nucleotides. 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. In humans there are two distinct microRNAs that share an identical mature sequence, and these are called miR-1-1 and miR-1-2.

mir-29 microRNA precursor

The miR-29 microRNA precursor, or pre-miRNA, is a small RNA molecule in the shape of a stem-loop or hairpin. Each arm of the hairpin can be processed into one member of a closely related family of short non-coding RNAs that are involved in regulating gene expression. The processed, or "mature" products of the precursor molecule are known as microRNA (miRNA), and have been predicted or confirmed in a wide range of species.

mir-2 microRNA precursor

The mir-2 microRNA family includes the microRNA genes mir-2 and mir-13. Mir-2 is widespread in invertebrates, and it is the largest family of microRNAs in the model species Drosophila melanogaster. MicroRNAs from this family are produced from the 3' arm of the precursor hairpin. Leaman et al. showed that the miR-2 family regulates cell survival by translational repression of proapoptotic factors. Based on computational prediction of targets, a role in neural development and maintenance has been suggested.

The miR-34 microRNA precursor family are non-coding RNA molecules that, in mammals, give rise to three major mature miRNAs. The miR-34 family members were discovered computationally and later verified experimentally. The precursor miRNA stem-loop is processed in the cytoplasm of the cell, with the predominant miR-34 mature sequence excised from the 5' arm of the hairpin.

mir-92 microRNA precursor family

The miR-92 microRNAs are short single stranded non-protein coding RNA fragments initially discovered incorporated into an RNP complex with a proposed role of processing RNA molecules and further RNP assembly. Mir-92 has been mapped to the human genome as part of a larger cluster at chromosome 13q31.3, where it is 22 nucleotides in length but exists in the genome as part of a longer precursor sequence. There is an exact replica of the mir-92 precursor on the X chromosome. MicroRNAs are endogenous triggers of the RNAi pathway which involves several ribonucleic proteins (RNPs) dedicated to repressing mRNA molecules via translation inhibition and/or induction of mRNA cleavage. miRNAs are themselves matured from their long RNA precursors by ribonucleic proteins as part of a 2 step biogenesis mechanism involving RNA polymerase 2.

mir-126

In molecular biology mir-126 is a short non-coding RNA molecule. MicroRNAs function to regulate the expression levels of other genes by several pre- and post-transcription mechanisms.

mir-143 RNA molecule

In molecular biology mir-143 microRNA is a short RNA molecule. MicroRNAs function to regulate the expression levels of other genes by several mechanisms. mir–143 is highly conserved in vertebrates. mir-143 is thought be involved in cardiac morphogenesis but has also been implicated in cancer.

mir-145 Non-coding RNA in the species Homo sapiens

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.

mir-22

In molecular biology mir-22 microRNA is a short RNA molecule. MicroRNAs are an abundant class of molecules, approximately 22 nucleotides in length, which can post-transcriptionally regulate gene expression by binding to the 3' UTR of mRNAs expressed in a cell.

mir-223 Mir-223

In molecular biology MicroRNA-223 (miR-223) is a short RNA molecule. MicroRNAs function to regulate the expression levels of other genes by several mechanisms. miR-223 is a hematopoietic specific microRNA with crucial functions in myeloid lineage development. It plays an essential role in promoting granulocytic differentiation while also being associated with the suppression of erythrocytic differentiation. miR-223 is commonly repressed in hepatocellular carcinoma and leukemia. Higher expression levels of miRNA-223 are associated with extranodal marginal-zone lymphoma of mucosa-associated lymphoid tissue of the stomach and recurrent ovarian cancer. In some cancers the microRNA-223 down-regulation is correlated with higher tumor burden, disease aggressiveness, and poor prognostic factors. MicroRNA-223 is also associated with rheumatoid arthritis, sepsis, type 2 diabetes, and hepatic ischemia.

mir-210 microRNA

In molecular biology mir-210 microRNA is a short RNA molecule. MicroRNAs function to regulate the expression levels of other genes by several mechanisms.

miR-27 Family of microRNA precursors found in animals

miR-27 is a family of microRNA precursors found in animals, including humans. MicroRNAs are typically transcribed as ~70 nucleotide precursors and subsequently processed by the Dicer enzyme to give a ~22 nucleotide product. The excised region or, mature product, of the miR-27 precursor is the microRNA mir-27.

miR-296

miR-296 is a family of microRNA precursors found in mammals, including humans. The ~22 nucleotide mature miRNA sequence is excised from the precursor hairpin by the enzyme Dicer. This sequence then associates with RISC which effects RNA interference.

mir-279 is a short RNA molecule found in Drosophila melanogaster that belongs to a class of molecules known as microRNAs. microRNAs are ~22nt-long non-coding RNAs that post-transcriptionally regulate the expression of genes, often by binding to the 3' untranslated region of mRNA, targeting the transcript for degradation. miR-279 has diverse tissue-specific functions in the fly, influencing developmental processes related to neurogenesis and oogenesis, as well as behavioral processes related to circadian rhythms. The varied roles of mir-279, both in the developing and adult fly, highlight the utility of microRNAs in regulating unique biological processes.

References

  1. ↑ "miRNA gene family: mir-7 (92 sequences)". MiRBase. Archived from the original on 2007-09-29.
  2. 1 2 3 Reddy SD, Ohshiro K, Rayala SK, Kumar R (October 2008). "MicroRNA-7, a homeobox D10 target, inhibits p21-activated kinase 1 and regulates its functions". Cancer Research. 68 (20): 8195–200. doi:10.1158/0008-5472.CAN-08-2103. PMC   3636563 . PMID   18922890.
  3. 1 2 Li X, Cassidy JJ, Reinke CA, Fischboeck S, Carthew RW (April 2009). "A microRNA imparts robustness against environmental fluctuation during development". Cell. 137 (2): 273–82. doi:10.1016/j.cell.2009.01.058. PMC   2674871 . PMID   19379693.
  4. 1 2 Webster RJ, Giles KM, Price KJ, Zhang PM, Mattick JS, Leedman PJ (February 2009). "Regulation of epidermal growth factor receptor signaling in human cancer cells by microRNA-7". The Journal of Biological Chemistry. 284 (9): 5731–41. doi: 10.1074/jbc.M804280200 . PMID   19073608.
  5. ↑ Li X, Carthew RW (December 2005). "A microRNA mediates EGF receptor signaling and promotes photoreceptor differentiation in the Drosophila eye". Cell. 123 (7): 1267–77. doi: 10.1016/j.cell.2005.10.040 . PMID   16377567.
  6. 1 2 Jiang L, Liu X, Chen Z, Jin Y, Heidbreder CE, Kolokythas A, Wang A, Dai Y, Zhou X (November 2010). "MicroRNA-7 targets IGF1R (insulin-like growth factor 1 receptor) in tongue squamous cell carcinoma cells". The Biochemical Journal. 432 (1): 199–205. doi:10.1042/BJ20100859. PMC   3130335 . PMID   20819078.
  7. ↑ Stark A, Brennecke J, Russell RB, Cohen SM (December 2003). "Identification of Drosophila MicroRNA targets". PLOS Biology. 1 (3): E60. doi: 10.1371/journal.pbio.0000060 . PMC   270017 . PMID   14691535. Open Access logo PLoS transparent.svg
  8. ↑ Lee HJ, Palkovits M, Young WS (October 2006). "miR-7b, a microRNA up-regulated in the hypothalamus after chronic hyperosmolar stimulation, inhibits Fos translation". Proceedings of the National Academy of Sciences of the United States of America. 103 (42): 15669–74. doi: 10.1073/pnas.0605781103 . PMC   1622879 . PMID   17028171.
  9. ↑ de Chevigny A (2012). "miR-7a regulation of Pax6 controls spatial origin of forebrain dopaminergic neurons". Nature Neuroscience. 15 (8): 1120–1126. doi:10.1038/nn.3142. PMID   22729175. S2CID   8456253.
  10. ↑ Kefas B, Godlewski J, Comeau L, Li Y, Abounader R, Hawkinson M, Lee J, Fine H, Chiocca EA, Lawler S, Purow B (May 2008). "microRNA-7 inhibits the epidermal growth factor receptor and the Akt pathway and is down-regulated in glioblastoma". Cancer Research. 68 (10): 3566–72. doi: 10.1158/0008-5472.CAN-07-6639 . PMID   18483236.
  11. ↑ Foekens JA, Sieuwerts AM, Smid M, Look MP, de Weerd V, Boersma AW, Klijn JG, Wiemer EA, Martens JW (September 2008). "Four miRNAs associated with aggressiveness of lymph node-negative, estrogen receptor-positive human breast cancer". Proceedings of the National Academy of Sciences of the United States of America. 105 (35): 13021–6. Bibcode:2008PNAS..10513021F. doi: 10.1073/pnas.0803304105 . PMC   2529088 . PMID   18755890.
  12. ↑ Veerla S, Lindgren D, Kvist A, Frigyesi A, Staaf J, Persson H, Liedberg F, Chebil G, Gudjonsson S, Borg A, Månsson W, Rovira C, Höglund M (May 2009). "MiRNA expression in urothelial carcinomas: important roles of miR-10a, miR-222, miR-125b, miR-7 and miR-452 for tumor stage and metastasis, and frequent homozygous losses of miR-31". International Journal of Cancer. 124 (9): 2236–42. doi: 10.1002/ijc.24183 . PMID   19127597.
  13. ↑ Perkins DO, Jeffries CD, Jarskog LF, Thomson JM, Woods K, Newman MA, Parker JS, Jin J, Hammond SM (2007). "microRNA expression in the prefrontal cortex of individuals with schizophrenia and schizoaffective disorder". Genome Biology. 8 (2): R27. doi: 10.1186/gb-2007-8-2-r27 . PMC   1852419 . PMID   17326821.
  14. ↑ Arora A, McKay GJ, Simpson DA (September 2007). "Prediction and verification of miRNA expression in human and rat retinas". Investigative Ophthalmology & Visual Science. 48 (9): 3962–7. doi: 10.1167/iovs.06-1221 . PMID   17724173.
  15. ↑ Czech MP (March 2006). "MicroRNAs as therapeutic targets". The New England Journal of Medicine. 354 (11): 1194–5. doi:10.1056/NEJMcibr060065. PMID   16540623.

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