title: The ability of Fos family members to produce phenotypic changes in epithelioid cells is not directly linked to their transactivation potentials.
abstract: Numerous studies have revealed distinct functions of Fos proteins in different mouse tissues and cell lines. Here, we perform a direct comparison of the features of exogenous c-Fos, Fra-1 and Fra-2 proteins expressed in murine tumor cells of epithelial origin, CSML0. Although transactivation potential of c-Fos is much stronger than that of Fra-1 and Fra-2, all three proteins are capable of modulating transcription of target genes. Moreover, there is a certain degree of specificity in the induction of the transcription of AP-1-responsive genes by different Fos proteins. For instance, c-Fos and Fra-1 but not Fra-2 activated genes of the urokinase system. Additionally, not only a strong transcriptional activator c-Fos, but also Fra-1 induced morphological alterations in CSML0 cells. N-terminal domain of Fra-1 was required for this function. On the other hand, Fra-2 failed to change morphology of CSML0 cells. We therefore conclude that c-Fos, Fra-1 and Fra-2 differently activate transcription of target genes and induce morphological changes in epithelioid carcinoma cells in a manner not directly linked to their transactivation potentials.
authors.affiliation: Danish Cancer Society, Department of Molecular Cancer Biology, Strandboulevarden 49, DK-2100, Copenhagen Ø, Denmark.
authors.forename: Henriette
authors.initials: H
authors.lastname: Andersen
authors.forename: Shaukat
authors.initials: S
authors.lastname: Mahmood
authors.forename: Vadim
authors.initials: V
authors.lastname: Tkach
authors.forename: Martin
authors.initials: M
authors.lastname: Cohn
authors.forename: Olga
authors.initials: O
authors.lastname: Kustikova
authors.forename: Mariam
authors.initials: M
authors.lastname: Grigorian
authors.forename: Vladimir
authors.initials: V
authors.lastname: Berezin
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Bock
authors.forename: Eugene
authors.initials: E
authors.lastname: Lukanidin
authors.forename: Eugene
authors.initials: E
authors.lastname: Tulchinsky
mesh_terms: D000818:Animals; D002277:Carcinoma / Q000235:genetics* / Q000473:pathology*; D002460:Cell Line; D048429:Cell Size; D004268:DNA-Binding Proteins / Q000502:physiology*; D015622:Epithelioid Cells / Q000378:metabolism; D051921:Fos-Related Antigen-2; D051379:Mice; D010641:Phenotype; D016760:Proto-Oncogene Proteins c-fos / Q000502:physiology*; D015534:Trans-Activators / Q000502:physiology; D014157:Transcription Factors / Q000502:physiology*; D015533:Transcriptional Activation; D014407:Tumor Cells, Cultured; D000099169:Fos-Related Antigen 1
chemical_list: D004268:DNA-Binding Proteins; D051921:Fos-Related Antigen-2; D016760:Proto-Oncogene Proteins c-fos; D015534:Trans-Activators; D014157:Transcription Factors; D000099169:Fos-Related Antigen 1; C497873:Fosl2 protein, mouse