title: ERK/p90(RSK)/14-3-3 signalling has an impact on expression of PEA3 Ets transcription factors via the transcriptional repressor capicúa.
abstract: Compounds that inhibit signalling upstream of ERK (extracellular-signal-regulated kinase) are promising anticancer therapies, motivating research to define how this pathway promotes cancers. In the present study, we show that human capicúa represses mRNA expression for PEA3 (polyoma enhancer activator 3) Ets transcription factors ETV1, ETV4 and ETV5 (ETV is Ets translocation variant), and this repression is relieved by multisite controls of capicúa by ERK, p90(RSK) (p90 ribosomal S6 kinase) and 14-3-3 proteins. Specifically, 14-3-3 binds to p90(RSK)-phosphorylated Ser¹⁷³ of capicúa thereby modulating DNA binding to its HMG (high-mobility group) box, whereas ERK phosphorylations prevent binding of a C-terminal NLS (nuclear localization sequence) to importin α4 (KPNA3). ETV1, ETV4 and ETV5 mRNA levels in melanoma cells are elevated by siRNA (small interfering RNA) knockdown of capicúa, and decreased by inhibiting ERK and/or expressing a form of capicúa that cannot bind to 14-3-3 proteins. Capicúa knockdown also enhances cell migration. The findings of the present study give further mechanistic insights into why ETV1 is highly expressed in certain cancers, indicate that loss of capicúa can desensitize cells to the effects of ERK pathway inhibitors, and highlight interconnections among growth factor signalling, spinocerebellar ataxias and cancers.
authors.affiliation: University of Dundee, Scotland, UK.
authors.forename: Kumara
authors.initials: K
authors.lastname: Dissanayake
authors.forename: Rachel
authors.initials: R
authors.lastname: Toth
authors.forename: Jamie
authors.initials: J
authors.lastname: Blakey
authors.forename: Olof
authors.initials: O
authors.lastname: Olsson
authors.forename: David G
authors.initials: DG
authors.lastname: Campbell
authors.forename: Alan R
authors.initials: AR
authors.lastname: Prescott
authors.forename: Carol
authors.initials: C
authors.lastname: MacKintosh
mesh_terms: D048948:14-3-3 Proteins / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000096:biosynthesis / Q000235:genetics; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism*; D006801:Humans; D008545:Melanoma / Q000378:metabolism; D050783:Proto-Oncogene Proteins c-ets / Q000096:biosynthesis / Q000235:genetics; D012333:RNA, Messenger / Q000032:analysis; D012097:Repressor Proteins / Q000502:physiology*; D038744:Ribosomal Protein S6 Kinases, 90-kDa / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology*; D014157:Transcription Factors / Q000096:biosynthesis / Q000235:genetics*
chemical_list: D048948:14-3-3 Proteins; C498610:CIC protein, human; D004268:DNA-Binding Proteins; C095239:ETV1 protein, human; D050783:Proto-Oncogene Proteins c-ets; D012333:RNA, Messenger; D012097:Repressor Proteins; D014157:Transcription Factors; C065788:transcription factor PEA3; D038744:Ribosomal Protein S6 Kinases, 90-kDa; D048049:Extracellular Signal-Regulated MAP Kinases