FREBP - an anchorage dependent transcription factor

dc.contributor.author Singh, Gulshan
dc.contributor.department Theses & dissertations (Interdisciplinary)
dc.date 2020-08-21T23:11:03.000
dc.date.accessioned 2021-02-26T08:49:56Z
dc.date.available 2021-02-26T08:49:56Z
dc.date.copyright Thu Jan 01 00:00:00 UTC 2004
dc.date.issued 2004-01-01
dc.description.abstract <p>Mitogen-regulated protein3 (MRP3) is a bFGF-regulated gene containing the basic-fibroblast growth factor response element (FRE) in its proximal promoter. The unique FRE is transcriptionally active in a TK fusion promoter and to respond to bFGF. The FRE transcriptional element is also present in the promoters of many bFGF-regulated genes like mmp-3, mmp-2, mmp-1, and mmp-9. The FRE binds to nuclear factors derived from NIH 3T3 cells (mouse), CHO cells (hamster), HeLa cells (human), and from tissues like placenta (day 11) and fetus, regions where mrp3 is highly expressed. This [Difference]34kDa nuclear factor, named the Fibroblast growth factor response element binding protein (FREBP) is proposed to be the transcription factor regulating FRE-containing genes. The FREBP was shown to be an anchorage dependent protein with its activity declining over a period of 24h in suspension cultures of HeLa cells. Studies were conducted using inhibitors for the enzymes Ras, MEK kinase, Src kinase, and PI-3 kinase to investigate the involvement of extracellular regulated pathways like MAP kinase, PI-3 kinase, and FAK pathway in regulating the FREBP activity. The results showed that the MEK inhibitor PD 98059 inhibits FREBP activity in cells that were adherent to the ECM (p<0.001). This result suggested that MEK might be involved in regulating the FREBP activity in monolayer HeLa cells. The inhibitors for the other molecules, like PP2 (Src kinase), Ly294002 (PI-3 kinase), and Ftase inhibitor (Ras), did not significantly reduce FREBP activity in monolayer cultures. To know whether MEK activity regulates FREBP activity in an anchorage dependent manner, the following studies were undertaken. First, activity of MEK established in suspended HeLa cells over a 24h time course. Second, effect of inhibiting MEK activity over a 24h time course determined. Results showed that MEK activity decreases more slowly than the FREBP activity in suspended HeLa cells (Half-life: FREBP: [Difference]2h, MEK: [Difference]18h). Thus, MEK does not inhibit FREBP activity in suspension cultures, and also inhibiting MEK did not have an effect on the FREBP activity in suspended cells. Based on our studies, we propose that MEK could be involved in regulating FREBP in Monolayer cells but not in suspended HeLa cells.</p>
dc.format.mimetype application/pdf
dc.identifier archive/lib.dr.iastate.edu/rtd/20270/
dc.identifier.articleid 21269
dc.identifier.contextkey 18970572
dc.identifier.doi https://doi.org/10.31274/rtd-20200817-63
dc.identifier.s3bucket isulib-bepress-aws-west
dc.identifier.submissionpath rtd/20270
dc.identifier.uri https://dr.lib.iastate.edu/handle/20.500.12876/97637
dc.language.iso en
dc.source.bitstream archive/lib.dr.iastate.edu/rtd/20270/Singh_ISU_2004_S584.pdf|||Fri Jan 14 22:22:20 UTC 2022
dc.subject.keywords Biochemistry, biophysics, and molecular biology
dc.subject.keywords Toxicology
dc.title FREBP - an anchorage dependent transcription factor
dc.type article
dc.type.genre thesis
dspace.entity.type Publication
thesis.degree.discipline Toxicology
thesis.degree.level thesis
thesis.degree.name Master of Science
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