HOTTIP explained

In molecular biology, HOTTIP (HOXA transcript at the distal tip) is a long non-coding RNA. The gene encoding HOTTIP is located at the 5′ tip of the HOXA locus, and coordinates the activation of several of the 5′ HOXA genes. The non-coding RNA is brought into close proximity with the HOXA genes by chromosomal looping. HOTTIP binds to the WDR5 protein, which forms a complex with the histone methyltransferase protein MLL. This targets the WDR5-MLL complex to the HOXA region and results in H3K4 methylation and transcriptional activation of the HOXA locus.^[1] More recently, HOTTIP has been shown to play a role in Hepatocellular Carcinoma (HCC) progression. HOTTIP expression levels predict metastasis formation and poor disease outcome in HCC patients.^[2] HOTTIP has been shown to be transcriptionally regulated by a transcriptional coactivator PSIP1/p52^[3]

See also

• Long noncoding RNA

Further reading

• Burgess DJ. Non-coding RNA: HOTTIP goes the distance. . Nat Rev Genet . 2011 . 12 . 5 . 300 . 21483457 . 10.1038/nrg2992 . 27802734 . free .

Notes and References

1. Wang KC, Yang YW, Liu B, Sanyal A, Corces-Zimmerman R, Chen Y, etal . A long noncoding RNA maintains active chromatin to coordinate homeotic gene expression. . Nature . 2011 . 472 . 7341 . 120–124 . 21423168 . 10.1038/nature09819 . 3670758. 2011Natur.472..120W .
2. 24114970 . 10.1002/hep.26740 . 59 . 3 . Long noncoding RNA HOTTIP/HOXA13 expression is associated with disease progression and predicts outcome in hepatocellular carcinoma patients . 3943759 . 2014 . Hepatology . 911–23 . Quagliata . L . Matter . MS . Piscuoglio . S . Arabi . L . Ruiz . C . Procino . A . Kovac . M . Moretti . F . Makowska . Z . Boldanova . T . Andersen . JB . Hämmerle . M . Tornillo . L . Heim . MH . Diederichs . S . Cillo . C . Terracciano . LM.
3. Pradeepa. Madapura M.. McKenna. Fionnuala. Taylor. Gillian C. A.. Bengani. Hemant. Grimes. Graeme R.. Wood. Andrew J.. Bhatia. Shipra. Bickmore. Wendy A.. 2017-04-06. Psip1/p52 regulates posterior Hoxa genes through activation of lncRNA Hottip. PLOS Genetics. 13. 4. e1006677. 10.1371/journal.pgen.1006677. 1553-7404. 5383017. 28384324 . free .