title: Transcriptional regulation of flotillins by the extracellularly regulated kinases and retinoid X receptor complexes.
abstract: Flotillin-1 and flotillin-2 are important regulators of signal transduction pathways such as growth factor signaling. Flotillin expression is increased under pathological conditions such as neurodegenerative disorders and cancer. Despite their importance for signal transduction, very little is known about the transcriptional regulation of flotillins. Here, we analyzed the expression of flotillins at transcriptional level and identified flotillins as downstream targets of the mitogen activated kinases ERK1/2. The promoter activity of flotillins was increased upon growth factor stimulation in a MAPK dependent manner. Overexpression of serum response factor or early growth response gene 1 resulted in increased flotillin mRNA and protein expression. Furthermore, both promoter activity and expression of endogenous flotillins were increased upon treatment with retinoic acid or by overexpression of the retinoid X receptor and its binding partners RARα and PPARγ. Our data indicate that the expression of flotillins, which can be detected in all cultured cells, is fine-tuned in response to various external stimuli. This regulation may be critical for the outcome of signaling cascades in which flotillins are known to be involved.
authors.affiliation: Institute of Biochemistry, Medical Faculty, University of Giessen, Giessen, Germany.
authors.forename: Antje
authors.initials: A
authors.lastname: Banning
authors.forename: Wymke
authors.initials: W
authors.lastname: Ockenga
authors.forename: Fabian
authors.initials: F
authors.lastname: Finger
authors.forename: Philipp
authors.initials: P
authors.lastname: Siebrasse
authors.forename: Ritva
authors.initials: R
authors.lastname: Tikkanen
mesh_terms: D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D002460:Cell Line; D017124:Conserved Sequence; D051766:Early Growth Response Protein 1 / Q000378:metabolism; D004815:Epidermal Growth Factor / Q000494:pharmacology; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism*; D005786:Gene Expression Regulation; D006801:Humans; D020935:MAP Kinase Signaling System / Q000187:drug effects; D008565:Membrane Proteins / Q000235:genetics*; D051379:Mice; D008969:Molecular Sequence Data; D009154:Mutation; D047495:PPAR gamma / Q000378:metabolism; D011401:Promoter Regions, Genetic / Q000187:drug effects; D047488:Retinoid X Receptors / Q000378:metabolism*; D026362:Serum Response Factor / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism; D014158:Transcription, Genetic; D014212:Tretinoin / Q000378:metabolism
chemical_list: D051766:Early Growth Response Protein 1; D008565:Membrane Proteins; D047495:PPAR gamma; D047488:Retinoid X Receptors; D026362:Serum Response Factor; D014157:Transcription Factors; C106354:flotillins; D014212:Tretinoin; D004815:Epidermal Growth Factor; D048049:Extracellular Signal-Regulated MAP Kinases