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dc.contributor.authorSpriggs, Keith A
dc.contributor.authorCobbold, Laura C
dc.contributor.authorRidley, Simon
dc.contributor.authorColdwell, Mark
dc.contributor.authorBottley, Andrew
dc.contributor.authorBushell, Martin
dc.contributor.authorWillis, Anne
dc.contributor.authorSiddle, Kenneth
dc.date.accessioned2018-11-30T00:31:44Z
dc.date.available2018-11-30T00:31:44Z
dc.date.issued2009-09
dc.identifier.issn0305-1048
dc.identifier.urihttps://www.repository.cam.ac.uk/handle/1810/286126
dc.description.abstractRegulation of mRNA translation is an important mechanism determining the level of expression of proteins in eukaryotic cells. Translation is most commonly initiated by cap-dependent scanning, but many eukaryotic mRNAs contain internal ribosome entry segments (IRESs), providing an alternative means of initiation capable of independent regulation. Here, we show by using dicistronic luciferase reporter vectors that the 5'-UTR of the mRNA encoding human insulin receptor (hIR) contains a functional IRES. RNAi-mediated knockdown showed that the protein PTB was required for maximum IRES activity. Electrophoretic mobility shift assays confirmed that PTB1, PTB2 and nPTB, but not unr or PTB4, bound to hIR mRNA, and deletion mapping implicated a CCU motif 448 nt upstream of the initiator AUG in PTB binding. The IR-IRES was functional in a number of cell lines, and most active in cells of neuronal origin, as assessed by luciferase reporter assays. The IRES was more active in confluent than sub-confluent cells, but activity did not change during differentiation of 3T3-L1 fibroblasts to adipocytes. IRES activity was stimulated by insulin in sub-confluent cells. The IRES may function to maintain expression of IR protein in tissues such as the brain where mRNA translation by cap-dependent scanning is less effective.
dc.format.mediumPrint-Electronic
dc.languageeng
dc.publisherOxford University Press (OUP)
dc.rightsAttribution-NonCommercial 4.0 International
dc.rights.urihttps://creativecommons.org/licenses/by-nc/4.0/
dc.subjectCell Line
dc.subjectAnimals
dc.subjectHumans
dc.subjectMice
dc.subjectRats
dc.subjectInsulin
dc.subjectReceptor, Insulin
dc.subjectPolypyrimidine Tract-Binding Protein
dc.subjectRNA, Messenger
dc.subject5' Untranslated Regions
dc.subjectProtein Biosynthesis
dc.subjectBase Sequence
dc.subjectMolecular Sequence Data
dc.titleThe human insulin receptor mRNA contains a functional internal ribosome entry segment.
dc.typeArticle
prism.endingPage5893
prism.issueIdentifier17
prism.publicationDate2009
prism.publicationNameNucleic Acids Res
prism.startingPage5881
prism.volume37
dc.identifier.doi10.17863/CAM.33441
rioxxterms.versionofrecord10.1093/nar/gkp623
rioxxterms.licenseref.urihttp://www.rioxx.net/licenses/all-rights-reserved
rioxxterms.licenseref.startdate2009-09
dc.contributor.orcidWillis, Anne [0000-0002-1470-8531]
dc.identifier.eissn1362-4962
rioxxterms.typeJournal Article/Review
cam.issuedOnline2009-08-04


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Attribution-NonCommercial 4.0 International
Except where otherwise noted, this item's licence is described as Attribution-NonCommercial 4.0 International