View source for Mir-7 microRNA precursor

{{Infobox rfam
| Name = mir-7 microRNA precursor
| image = RF00053.jpg
| width = 
| caption = Predicted [[secondary structure]] and [[sequence conservation]] of mir-7
| Symbol = mir-7
| AltSymbols = 
| Rfam = RF00053
| miRBase = MI0000263
| miRBase_family = MIPF0000022
| RNA_type = [[Gene]]; [[MicroRNA|miRNA]]
| Tax_domain = [[Eukaryota]]
| GO = {{GO|0035195}} {{GO|0035068}} 
| SO = {{SO|0001244}} 
| CAS_number = 
| EntrezGene = 
| HGNCid = 
| OMIM = 
| PDB = 
| RefSeq = 
| Chromosome = 
| Arm = 
| Band = 
| LocusSupplementaryData = 
}}

This family represents the [[microRNA]] (miRNA) precursor mir-7. This miRNA has been predicted or experimentally confirmed in a wide range of species.<ref>{{cite web |url=http://microrna.sanger.ac.uk/cgi-bin/sequences/mirna_summary.pl?fam=MIPF0000022 |archive-url=https://web.archive.org/web/20070929111655/http://microrna.sanger.ac.uk/cgi-bin/sequences/mirna_summary.pl?fam=MIPF0000022 |url-status=dead |archive-date=2007-09-29 |publisher=[[MiRBase]] |title=miRNA gene family: mir-7 (92 sequences) }}</ref> 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' end|5']] arm of the precursor. The extents of the [[stem loop|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]].

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.<ref name="pmid18922890">{{cite journal | vauthors = Reddy SD, Ohshiro K, Rayala SK, Kumar R | title = MicroRNA-7, a homeobox D10 target, inhibits p21-activated kinase 1 and regulates its functions | journal = Cancer Research | volume = 68 | issue = 20 | pages = 8195–200 | date = October 2008 | pmid = 18922890 | pmc = 3636563 | doi = 10.1158/0008-5472.CAN-08-2103 }}</ref>

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.<ref name="pmid19379693">{{cite journal | vauthors = Li X, Cassidy JJ, Reinke CA, Fischboeck S, Carthew RW | title = A microRNA imparts robustness against environmental fluctuation during development | journal = Cell | volume = 137 | issue = 2 | pages = 273–82 | date = April 2009 | pmid = 19379693 | pmc = 2674871 | doi = 10.1016/j.cell.2009.01.058 }}</ref> It plays an important role in controlling mRNA expression. The miR-7 gene is found in most sequenced [[Urbilaterian|Urbilateria]] species, and the sequence of its mature miRNA product is perfectly conserved from [[annelid]]s to humans, indicating a strong functional conservation.<ref name="pmid19379693"/>

==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.<ref name="pmid19073608">{{cite journal | vauthors = Webster RJ, Giles KM, Price KJ, Zhang PM, Mattick JS, Leedman PJ | title = Regulation of epidermal growth factor receptor signaling in human cancer cells by microRNA-7 | journal = The Journal of Biological Chemistry | volume = 284 | issue = 9 | pages = 5731–41 | date = February 2009 | pmid = 19073608 | doi = 10.1074/jbc.M804280200 | doi-access = free }}</ref> In Drosophila photoreceptor cells, miR-7 controls epidermal growth factor receptor (EGFR) signaling and promotes photoreceptor differentiation.<ref name="pmid16377567">{{cite journal | vauthors = Li X, Carthew RW | title = A microRNA mediates EGF receptor signaling and promotes photoreceptor differentiation in the Drosophila eye | journal = Cell | volume = 123 | issue = 7 | pages = 1267–77 | date = December 2005 | pmid = 16377567 | doi = 10.1016/j.cell.2005.10.040 | doi-access = free }}</ref> Among other targets of miR-7 are [[insulin-like growth factor 1 receptor]] (IGF1R) and PIK3CD,<ref name="pmid20819078">{{cite journal | vauthors = Jiang L, Liu X, Chen Z, Jin Y, Heidbreder CE, Kolokythas A, Wang A, Dai Y, Zhou X | title = MicroRNA-7 targets IGF1R (insulin-like growth factor 1 receptor) in tongue squamous cell carcinoma cells | journal = The Biochemical Journal | volume = 432 | issue = 1 | pages = 199–205 | date = November 2010 | pmid = 20819078 | pmc = 3130335 | doi = 10.1042/BJ20100859 }}</ref> E(spl) gene family <ref name="pmid14691535">{{cite journal | vauthors = Stark A, Brennecke J, Russell RB, Cohen SM | title = Identification of Drosophila MicroRNA targets | journal = PLOS Biology | volume = 1 | issue = 3 | pages = E60 | date = December 2003 | pmid = 14691535 | pmc = 270017 | doi = 10.1371/journal.pbio.0000060 | doi-access = free }} {{open access}}</ref> and Pak1 (cancer cells).<ref name="pmid18922890"/> [[c-Fos]] is also a target of miR-7b in mice.<ref>{{cite journal | vauthors = Lee HJ, Palkovits M, Young WS | title = miR-7b, a microRNA up-regulated in the hypothalamus after chronic hyperosmolar stimulation, inhibits Fos translation | journal = Proceedings of the National Academy of Sciences of the United States of America | volume = 103 | issue = 42 | pages = 15669–74 | date = October 2006 | pmid = 17028171 | pmc = 1622879 | doi = 10.1073/pnas.0605781103 | doi-access = free }}</ref> [[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.<ref name="pmid22729175">{{cite journal | doi = 10.1038/nn.3142 | volume=15 | title=miR-7a regulation of Pax6 controls spatial origin of forebrain dopaminergic neurons | year=2012 | journal=Nature Neuroscience | pages=1120–1126 | vauthors=de Chevigny A| issue=8 | pmid=22729175 | s2cid=8456253 }}</ref>

==Clinical relevance==
Multiple roles and targets of miR-7 as well as its expression pattern were linked to regulatory mechanisms and pathogenesis in [[glioblastoma]],<ref name="pmid18483236">{{cite journal | vauthors = Kefas B, Godlewski J, Comeau L, Li Y, Abounader R, Hawkinson M, Lee J, Fine H, Chiocca EA, Lawler S, Purow B | title = microRNA-7 inhibits the epidermal growth factor receptor and the Akt pathway and is down-regulated in glioblastoma | journal = Cancer Research | volume = 68 | issue = 10 | pages = 3566–72 | date = May 2008 | pmid = 18483236 | doi = 10.1158/0008-5472.CAN-07-6639 | doi-access = free }}</ref> breast cancer<ref name="pmid18755890">{{cite journal | vauthors = Foekens JA, Sieuwerts AM, Smid M, Look MP, de Weerd V, Boersma AW, Klijn JG, Wiemer EA, Martens JW | title = Four miRNAs associated with aggressiveness of lymph node-negative, estrogen receptor-positive human breast cancer | journal = Proceedings of the National Academy of Sciences of the United States of America | volume = 105 | issue = 35 | pages = 13021–6 | date = September 2008 | pmid = 18755890 | pmc = 2529088 | doi = 10.1073/pnas.0803304105 | bibcode = 2008PNAS..10513021F | doi-access = free }}</ref> and other types of cancers,<ref name="pmid19073608"/><ref name="pmid20819078"/><ref name="pmid19127597">{{cite journal | vauthors = 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 | title = 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 | journal = International Journal of Cancer | volume = 124 | issue = 9 | pages = 2236–42 | date = May 2009 | pmid = 19127597 | doi = 10.1002/ijc.24183 | doi-access = free }}</ref> as well as in schizophrenia<ref name="pmid17326821">{{cite journal | vauthors = Perkins DO, Jeffries CD, Jarskog LF, Thomson JM, Woods K, Newman MA, Parker JS, Jin J, Hammond SM | title = microRNA expression in the prefrontal cortex of individuals with schizophrenia and schizoaffective disorder | journal = Genome Biology | volume = 8 | issue = 2 | pages = R27 | year = 2007 | pmid = 17326821 | pmc = 1852419 | doi = 10.1186/gb-2007-8-2-r27 | doi-access = free }}</ref> and visual abnormalities.<ref name="pmid17724173">{{cite journal | vauthors = Arora A, McKay GJ, Simpson DA | title = Prediction and verification of miRNA expression in human and rat retinas | journal = Investigative Ophthalmology & Visual Science | volume = 48 | issue = 9 | pages = 3962–7 | date = September 2007 | pmid = 17724173 | doi = 10.1167/iovs.06-1221 | doi-access = free }}</ref> 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.<ref name="pmid18922890"/><ref name="pmid16540623">{{cite journal | vauthors = Czech MP | title = MicroRNAs as therapeutic targets | journal = The New England Journal of Medicine | volume = 354 | issue = 11 | pages = 1194–5 | date = March 2006 | pmid = 16540623 | doi = 10.1056/NEJMcibr060065 }}</ref>

== References ==
{{reflist|30em}}

== Further reading ==
{{refbegin}}
* {{cite journal | vauthors = Lagos-Quintana M, Rauhut R, Lendeckel W, Tuschl T | title = Identification of novel genes coding for small expressed RNAs | journal = Science | volume = 294 | issue = 5543 | pages = 853–8 | date = October 2001 | pmid = 11679670 | doi = 10.1126/science.1064921 | hdl = 11858/00-001M-0000-0012-F65F-2 | bibcode = 2001Sci...294..853L | s2cid = 18101169 | hdl-access = free }}
* {{cite journal | vauthors = Ambros V | title = microRNAs: tiny regulators with great potential | journal = Cell | volume = 107 | issue = 7 | pages = 823–6 | date = December 2001 | pmid = 11779458 | doi = 10.1016/S0092-8674(01)00616-X | doi-access = free }}
* {{cite journal | vauthors = Chen H, Shalom-Feuerstein R, Riley J, Zhang SD, Tucci P, Agostini M, Aberdam D, Knight RA, Genchi G, Nicotera P, Melino G, Vasa-Nicotera M | title = miR-7 and miR-214 are specifically expressed during neuroblastoma differentiation, cortical development and embryonic stem cells differentiation, and control neurite outgrowth in vitro | journal = Biochemical and Biophysical Research Communications | volume = 394 | issue = 4 | pages = 921–7 | date = April 2010 | pmid = 20230785 | doi = 10.1016/j.bbrc.2010.03.076 }}
* {{cite journal | vauthors = Doxakis E | title = Post-transcriptional regulation of alpha-synuclein expression by mir-7 and mir-153 | journal = The Journal of Biological Chemistry | volume = 285 | issue = 17 | pages = 12726–34 | date = April 2010 | pmid = 20106983 | pmc = 2857101 | doi = 10.1074/jbc.M109.086827 | doi-access = free }}
* {{cite journal | vauthors = Pek JW, Lim AK, Kai T | title = Drosophila maelstrom ensures proper germline stem cell lineage differentiation by repressing microRNA-7 | journal = Developmental Cell | volume = 17 | issue = 3 | pages = 417–24 | date = September 2009 | pmid = 19758565 | doi = 10.1016/j.devcel.2009.07.017 | doi-access = free }}
* {{cite journal | vauthors = Junn E, Lee KW, Jeong BS, Chan TW, Im JY, Mouradian MM | title = Repression of alpha-synuclein expression and toxicity by microRNA-7 | journal = Proceedings of the National Academy of Sciences of the United States of America | volume = 106 | issue = 31 | pages = 13052–7 | date = August 2009 | pmid = 19628698 | pmc = 2722353 | doi = 10.1073/pnas.0906277106 | bibcode = 2009PNAS..10613052J | doi-access = free }}
* {{cite journal | vauthors = Correa-Medina M, Bravo-Egana V, Rosero S, Ricordi C, Edlund H, Diez J, Pastori RL | title = MicroRNA miR-7 is preferentially expressed in endocrine cells of the developing and adult human pancreas | journal = Gene Expression Patterns | volume = 9 | issue = 4 | pages = 193–9 | date = April 2009 | pmid = 19135553 | doi = 10.1016/j.gep.2008.12.003 }}
{{refend}}

== External links ==
*{{Rfam|id=RF00053|name=mir-7 microRNA precursor}}
* {{cite web |url=http://atlasgeneticsoncology.org/Genes/MIRN71ID44356ch9q21.html |work=Atlas of Genetics and Cytogenetics in Oncology and Haematology |title=MIR7-1 (microRNA 7-1) |last=Purow |first=Benjamin |date=December 2008}}

{{miRNA precursor families}}

[[Category:MicroRNA]]
[[Category:MicroRNA precursor families]]