User:Bikgar/sandbox

From WikiProjectMed
Jump to navigation Jump to search

miR-11 microRNA precursor family (Final Draft)

miR-11 precursor
MiR-11 precursor secondary structure from Rfam
Predicted conserved secondary structure of mir-11 precursor from Rfam
Identifiers
SymbolmiR-11
RfamRF00813
miRBaseMI0000131
miRBase familyMIPF0000252
Other data
RNA typeNon-coding RNA; microRNA
Domain(s)Eukaryota;
PDB structuresPDBe

The miR-11 microRNA is a short twenty one nucleotide RNA molecule that regulates gene expression[1]. It is part of a single stranded group of RNAs called small temporal RNAs, that specifically regulate genes during development[1]. The miR-11 microRNA is excised from the miR-11 microRNA precursor (~70 nucleotides long) by a ribonuclease called Dicer[1]. Once cut out from the primary microRNA precursor, miR-11 can perform its function as a mature microRNA. MiR-11, like many other microRNAs, functions in post-transcriptional regulation of gene expression[2].

The miR-11 microRNA was initially believed to have been associated with the miR-2 microRNA family, but is now known to share a family motif with miR-6[3]. Both miR-2 and miR-11 have similar seed regions, but there is little overlap in function and expression patterns between the two[3]. These seed regions (6-8 nucleotides long) are used to target the RNA of interest and are located at the 5' end of animal mircroRNAs[4]. The miR-11 microRNA and miR-6 share an almost identical seed region and have similar expression patterns and functional overlap[3].

These microRNAs are found in both invertebrates and vertebrates, but have been primarily studied in the model organism Drosophila melanogaster[1]. The mir-11 gene is expressed in Drosophila melanogaster throughout all stages of development[1][5], but is decreased in adulthood[1]. Decreased levels of the mir-11 gene in Drosophila embryos caused an increase in cell death[6]. The miR-11 microRNA controls apoptosis through the regulation of proapoptotic genes[7].

Little is still know about the actual mechanisms behind mir-11 regulation and its functioning pathways[8].

Targets of miR-11

Some of the many genes regulated by miR-11 include:

dE2f1

The mir-11 gene is located within the last intron of the dE2f1 gene, a Drosophila homolog of the E2F1 human gene; Both mir-11 and dE2f1 are co-expressed[7][9][8]. The dE2f1 gene is associated with both cell proliferation and DNA damage-induced apoptosis[8], meaning it functions in both the cell growth and programmed cell death pathways. The over-expression of mir-11 suppresses the apoptotic function of dE2f1, while a non-functional mutant mir-11 does not[8]. In addition to this, over-expression of mir-11 has no direct impact on the cell proliferation function of dE2f1[8]. The mir-11 gene is only able to hinder the proapoptotic function of this Drosophila homolog[8].

Reaper (rpr)

Reaper is only expressed in the presence of DNA damage; it is expressed in cells that are destined to die[10]. This proapoptotic gene is one of the first genes in the apoptosis pathway and is essential for the process of programmed cell death[11]. It is directly regulated by dE2f1 and indirectly regulated by mir-11[7][8]. When mir-11 is over-expressed rpr is suppressed and when mir-11 is suppressed rpr is over-expressed in the presence of dE2f1[7][8].

Head involution defective (hid)

The head involution defective gene is also regulated by dE2f1 and indirectly regulated by mir-11[7][8]. This proapoptotic gene is transcriptionally expressed when dE2f1 is present within the cell[7][8]. In the presence of infrared radiation or UV radiation induced DNA damage the accumulation of the Hid protein alone can not cause programmed cell death[10]. Instead the expression of the reaper promoter sequence is needed to induce the transcription of p53, which then induces hid expression and ultimately leads to apoptosis[10].

Grim

Grim is not expressed in accordance with infrared radiation or UV radiation induced DNA damage[10]; grim has a similar amino-terminal to reaper and functions in a parallel pathway that leads to apoptosis[12]. The over-expression of grim in Drosophila cell cultures is known to cause an increase in apoptosis[10]. This gene is indirectly regulated by mir-11 through the regulation of dE2f1[7]. Grim is suppressed in the presence of an over-expressed mir-11 and is over-expressed when mir-11 is suppressed[7].

Sickle (skl)

Sickle is another proapoptotic gene regulated by dE2f1, which is regulated by mir-11[7]. This gene is expressed in all stages of Drosophila development, but suppressed in the adults[13].

References

  1. ^ a b c d e f Lagos-Quintana, Mariana; Rauhut, Reinhard; Lendeckel, Winfried; Tuschl, Thomas (2001-10-26). "Identification of Novel Genes Coding for Small Expressed RNAs". Science. 294 (5543): 853–858. doi:10.1126/science.1064921. ISSN 0036-8075. PMID 11679670.
  2. ^ Ambros, Victor. "The functions of animal microRNAs". Nature. 431 (7006): 350–355. doi:10.1038/nature02871.
  3. ^ a b c Marco, Antonio; Hooks, Katarzyna; Griffiths-Jones, Sam (2012-03-01). "Evolution and function of the extended miR-2 microRNA family". RNA Biology. 9 (3): 242–248. doi:10.4161/rna.19160. ISSN 1547-6286. PMC 3384581. PMID 22336713.
  4. ^ Lewis, Benjamin P.; Burge, Christopher B.; Bartel, David P. "Conserved Seed Pairing, Often Flanked by Adenosines, Indicates that Thousands of Human Genes are MicroRNA Targets". Cell. 120 (1): 15–20. doi:10.1016/j.cell.2004.12.035. ISSN 0092-8674.
  5. ^ Lai, Eric C. "Micro RNAs are complementary to 3′ UTR sequence motifs that mediate negative post-transcriptional regulation". Nature Genetics. 30 (4): 363–364. doi:10.1038/ng865.
  6. ^ Jovanovic, M.; Hengartner, M. O. (2006-01-01). "miRNAs and apoptosis: RNAs to die for". Oncogene. 25 (46): 6176–6187. doi:10.1038/sj.onc.1209912. ISSN 0950-9232.
  7. ^ a b c d e f g h i j k l m n Ge, W.; Chen, Y.-W.; Weng, R.; Lim, S. F.; Buescher, M.; Zhang, R.; Cohen, S. M. (2012-05-01). "Overlapping functions of microRNAs in control of apoptosis during Drosophila embryogenesis". Cell Death & Differentiation. 19 (5): 839–846. doi:10.1038/cdd.2011.161. ISSN 1350-9047. PMC 3321623. PMID 22095284.
  8. ^ a b c d e f g h i j k l m Truscott, Mary; Islam, Abul B. M. M. K.; López-Bigas, Núria; Frolov, Maxim V. (2011-09-01). "mir-11 limits the proapoptotic function of its host gene, dE2f1". Genes & Development. 25 (17): 1820–1834. doi:10.1101/gad.16947411. ISSN 0890-9369. PMC 3175718. PMID 21856777.
  9. ^ a b Truscott, Mary; Islam, Abul B. M. M. K.; Lightfoot, James; López-Bigas, Núria; Frolov, Maxim V. (2014-07-24). "An Intronic microRNA Links Rb/E2F and EGFR Signaling". PLoS Genet. 10 (7): e1004493. doi:10.1371/journal.pgen.1004493. PMC 4109884. PMID 25058496.{{cite journal}}: CS1 maint: unflagged free DOI (link)
  10. ^ a b c d e Bilak, Amber; Su, Tin Tin (2009-06-25). "Regulation of Drosophila melanogaster pro-apoptotic gene hid". Apoptosis. 14 (8): 943–949. doi:10.1007/s10495-009-0374-2. ISSN 1360-8185. PMC 3373429. PMID 19554451.
  11. ^ Zhou, Lei; Hashimi, Hassan; Schwartz, Lawrence M.; Nambu, John R. (1995-01-07). "Programmed cell death in the Drosophila central nervous system midline". Current Biology. 5 (7): 784–790. doi:10.1016/S0960-9822(95)00155-2. ISSN 0960-9822. PMID 7583125.
  12. ^ Chen, P.; Nordstrom, W.; Gish, B.; Abrams, J. M. (1996-07-15). "grim, a novel cell death gene in Drosophila". Genes & Development. 10 (14): 1773–1782. doi:10.1101/gad.10.14.1773. ISSN 0890-9369. PMID 8698237.
  13. ^ Srinivasula, Srinivasa M.; Datta, Pinaki; Kobayashi, Masatomo; Wu, Jia-Wei; Fujioka, Miki; Hegde, Ramesh; Zhang, ZhiJia; Mukattash, Rula; Fernandes-Alnemri, Teresa. "sickle, a Novel Drosophila Death Gene in the reaper/hid/grim Region, Encodes an IAP-Inhibitory Protein". Current Biology. 12 (2): 125–130. doi:10.1016/S0960-9822(01)00657-1. ISSN 0960-9822. PMID 11818063.
Retrieved from "https://mdwiki.org/wiki/User:Bikgar/sandbox"