Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
17
pubmed:dateCreated
2004-4-19
pubmed:abstractText
RNA helicase A (RHA) is a member of the DEAD/H family of RNA helicases and unwinds duplex RNA and DNA. Recent studies have shown that RHA regulates the activity of gene promoters. However, little information is available about the in vivo relevance of RHA in the regulation of natural genes. We previously characterized a nuclear protein (MEF1) that binds to the proximal promoter of the multidrug resistance gene (MDR1) and up-regulates the promoter activity. In the present study, we isolated and identified RHA as a component of the MEF1 complex by using DNA-affinity chromatography and mass spectrometry. The antibody against RHA specifically disrupted the complex formation in electrophoretic mobility shift assay, confirming the identity of RHA. Western blotting showed that RHA in drug-resistant cells had a higher molecular weight than that in drug-sensitive cells. Similar results were obtained when FLAG-tagged RHA was overexpressed in these cells. This size difference probably reflects posttranslational modification(s) of RHA in drug-resistant cells. Chromatin immunoprecipitation revealed that RHA occupies the MDR1 promoter in vivo. Overexpression of RHA enhanced expression of the MDR1 promoter/reporter construct and endogenous P-glycoprotein (P-gp), the MDR1 gene product, and increased drug resistance of drug-resistant cells but not the drug-sensitive counterpart. Introduction of short interfering RNA targeting the RHA gene sequence selectively knocked-down RHA expression and concomitantly reduced P-gp level. Thus, our study demonstrates, for the first time, the involvement of RHA in up-regulation of the MDR1 gene. Interactions of RHA with other protein factors in the MEF1 complex bound to the promoter element may contribute to P-gp overexpression and multidrug resistance phenotype in drug-resistant cancer cells.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/Autoantigens, http://linkedlifedata.com/resource/pubmed/chemical/Chromatin, http://linkedlifedata.com/resource/pubmed/chemical/Coloring Agents, http://linkedlifedata.com/resource/pubmed/chemical/DEAD-box RNA Helicases, http://linkedlifedata.com/resource/pubmed/chemical/DHX9 protein, human, http://linkedlifedata.com/resource/pubmed/chemical/DNA, http://linkedlifedata.com/resource/pubmed/chemical/DNA-Binding Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Luciferases, http://linkedlifedata.com/resource/pubmed/chemical/MEF1 protein, human, http://linkedlifedata.com/resource/pubmed/chemical/Neoplasm Proteins, http://linkedlifedata.com/resource/pubmed/chemical/P-Glycoprotein, http://linkedlifedata.com/resource/pubmed/chemical/Protein Isoforms, http://linkedlifedata.com/resource/pubmed/chemical/RNA, http://linkedlifedata.com/resource/pubmed/chemical/RNA, Small Interfering, http://linkedlifedata.com/resource/pubmed/chemical/RNA Helicases, http://linkedlifedata.com/resource/pubmed/chemical/Tetrazolium Salts, http://linkedlifedata.com/resource/pubmed/chemical/Thiazoles, http://linkedlifedata.com/resource/pubmed/chemical/Transcription Factors, http://linkedlifedata.com/resource/pubmed/chemical/thiazolyl blue
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
23
pubmed:volume
279
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
17134-41
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed-meshheading:14769796-Amino Acid Motifs, pubmed-meshheading:14769796-Autoantigens, pubmed-meshheading:14769796-Blotting, Western, pubmed-meshheading:14769796-Cell Line, Tumor, pubmed-meshheading:14769796-Cell Nucleus, pubmed-meshheading:14769796-Chromatin, pubmed-meshheading:14769796-Chromatography, Affinity, pubmed-meshheading:14769796-Coloring Agents, pubmed-meshheading:14769796-DEAD-box RNA Helicases, pubmed-meshheading:14769796-DNA, pubmed-meshheading:14769796-DNA-Binding Proteins, pubmed-meshheading:14769796-Dose-Response Relationship, Drug, pubmed-meshheading:14769796-Drug Resistance, Multiple, pubmed-meshheading:14769796-Electroporation, pubmed-meshheading:14769796-HL-60 Cells, pubmed-meshheading:14769796-Humans, pubmed-meshheading:14769796-Luciferases, pubmed-meshheading:14769796-Mass Spectrometry, pubmed-meshheading:14769796-Neoplasm Proteins, pubmed-meshheading:14769796-P-Glycoprotein, pubmed-meshheading:14769796-Phenotype, pubmed-meshheading:14769796-Plasmids, pubmed-meshheading:14769796-Precipitin Tests, pubmed-meshheading:14769796-Promoter Regions, Genetic, pubmed-meshheading:14769796-Protein Isoforms, pubmed-meshheading:14769796-Protein Processing, Post-Translational, pubmed-meshheading:14769796-RNA, pubmed-meshheading:14769796-RNA, Small Interfering, pubmed-meshheading:14769796-RNA Helicases, pubmed-meshheading:14769796-Spectrometry, Mass, Matrix-Assisted Laser..., pubmed-meshheading:14769796-Tetrazolium Salts, pubmed-meshheading:14769796-Thiazoles, pubmed-meshheading:14769796-Transcription Factors, pubmed-meshheading:14769796-Transcriptional Activation, pubmed-meshheading:14769796-Up-Regulation
pubmed:year
2004
pubmed:articleTitle
RNA helicase A in the MEF1 transcription factor complex up-regulates the MDR1 gene in multidrug-resistant cancer cells.
pubmed:affiliation
Department of Pharmacology and Toxicology and Indiana University Cancer Center, Indianapolis, Indiana 46202.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.