Biology:KCNQ1OT1

From HandWiki
A representation of the 3D structure of the protein myoglobin showing turquoise α-helices.
Generic protein structure example

KCNQ1 overlapping transcript 1, also known as KCNQ1OT1, is a long non-coding RNA gene found in the KCNQ1 locus. This locus consists of 8–10 protein-coding genes, specifically expressed from the maternal allele (including the KCNQ1 gene), and the paternally expressed non-coding RNA gene KCNQ1OT1.[1] KCNQ1OT1 and KCNQ1 are imprinted genes and are part of an imprinting control region (ICR). Mitsuya identified that KCNQ1OT1 is an antisense transcript of KCNQ1. KCNQ1OT1 is a paternally expressed allele and KCNQ1 is a maternally expressed allele.[2] KCNQ1OT1 is a nuclear, 91 kb transcript, found in close proximity to the nucleolus in certain cell types.[3][4]

It interacts with chromatin, the histone methyltransferase G9a (responsible for the mono- and dimethylation of histone 3 lysine 9, H3K9), and the Polycomb Repressive Complex 2, PRC2, (responsible for the trimethylation of H3K27).[3] It plays an important role in the transcriptional silencing of the KCNQ1 locus by regulating histone methylation.[1] An 890 bp region at the 5′ end of KCNQ1OT1 acts as a silencing domain.[5][6] This region regulates CpG methylation levels of somatically acquired differentially methylated regions (DMRs), mediates the interaction of KCNQ1OT1 with chromatin and with DNA (cytosine-5)-methyltransferase 1 (DNMT1), but does not affect the interactions of histone methyltransferases with KCNQ1OT1.[6]

The misregulation of the imprinted gene KCNQ1OT1 can lead to a variety of abnormalities. The loss of the maternal methylation of the KCNQ1OT1 allele is most commonly associated with Beckwith-Wiedemann syndrome.[7] The deletion of KCNQ1OT1 in males can result in a removal of the repressor in six cis genes.[8] Offspring from the males that had KCNQ1OT1 knocked out weighed 20–25% less than the control.[8] If the deletion occurred in females, their offspring had no growth restrictions. Furthermore, uniparental paternal disomy (UPD) of KCNQ1OT1 is strongly associated with Wilms’ tumor. In fact, three out of four patients with Beckwith-Wiedemann Syndrome and Wilms’ tumor had UPD.[9] When KCNQ1OT1 transcript is truncated, normally repressed alleles on the paternal chromosome are instead expressed.[10] As the evidence shows, the misregulation of KCNQ1OT1 can lead to disastrous physical and genetic effects.

See also

  • Long noncoding RNA
  • Beckwith-Wiedemann syndrome

References

  1. ↑ 1.0 1.1 "Kcnq1ot1: a chromatin regulatory RNA". Seminars in Cell & Developmental Biology 22 (4): 343–350. June 2011. doi:10.1016/j.semcdb.2011.02.020. PMID 21345374. 
  2. ↑ "LIT1, an imprinted antisense RNA in the human KvLQT1 locus identified by screening for differentially expressed transcripts using monochromosomal hybrids". Human Molecular Genetics 8 (7): 1209–1217. July 1999. doi:10.1093/hmg/8.7.1209. PMID 10369866. 
  3. ↑ 3.0 3.1 "Kcnq1ot1 antisense noncoding RNA mediates lineage-specific transcriptional silencing through chromatin-level regulation". Molecular Cell 32 (2): 232–246. October 2008. doi:10.1016/j.molcel.2008.08.022. PMID 18951091. 
  4. ↑ "Differentiation-driven nucleolar association of the mouse imprinted Kcnq1 locus". G3 2 (12): 1521–1528. December 2012. doi:10.1534/g3.112.004226. PMID 23275875. 
  5. ↑ "Kcnq1ot1/Lit1 noncoding RNA mediates transcriptional silencing by targeting to the perinucleolar region". Molecular and Cellular Biology 28 (11): 3713–3728. June 2008. doi:10.1128/MCB.02263-07. PMID 18299392. 
  6. ↑ 6.0 6.1 "Kcnq1ot1 noncoding RNA mediates transcriptional gene silencing by interacting with Dnmt1". Development 137 (15): 2493–2499. August 2010. doi:10.1242/dev.048181. PMID 20573698. 
  7. ↑ "Epigenotype-phenotype correlations in Beckwith-Wiedemann syndrome". Journal of Medical Genetics 37 (12): 921–926. December 2000. doi:10.1136/jmg.37.12.921. PMID 11106355. 
  8. ↑ 8.0 8.1 "Regional loss of imprinting and growth deficiency in mice with a targeted deletion of KvDMR1". Nature Genetics 32 (3): 426–431. November 2002. doi:10.1038/ng988. PMID 12410230. 
  9. ↑ "Uniparental paternal disomy in a genetic cancer-predisposing syndrome" (in en). Nature 351 (6328): 665–667. June 1991. doi:10.1038/351665a0. PMID 1675767. Bibcode: 1991Natur.351..665H. 
  10. ↑ "Elongation of the Kcnq1ot1 transcript is required for genomic imprinting of neighboring genes" (in en). Genes & Development 20 (10): 1268–1282. May 2006. doi:10.1101/gad.1416906. PMID 16702402. 

Further reading



Retrieved from "https://handwiki.org/wiki/index.php?title=Biology:KCNQ1OT1&oldid=3595734"