title: Identification of c-Fos as a mitotic phosphoprotein: regulation of c-Fos by Aurora-A.
abstract: The c-Fos has been implicated in the regulation of gene expression under a variety of stimuli. It is known that c-Fos undergoes protein phosphorylation, which may subsequently modulate diverse functions in cells. However, less is known about the role and phosphorylation status of c-Fos during mitosis. Here, we showed that c-Fos exhibited an electrophoretic mobility up-shift as detected by SDS-PAGE during mitosis, which is an indication of protein phosphorylation. Aurora-A, but not Aurora-B or -C, serves as one of the kinases catalyzing the mitotic phosphorylation of c-Fos. The mobility up-shift was partially abolished by introducing siRNA or a catalytically inactive form of Aurora-A. Moreover, ectopic expression of the wild type, but not the catalytically inactive form of Aurora-A resulted in the alteration of c-Fos complex formation, suggesting Aurora-A is engaged in the regulation of c-Fos protein-protein interaction. These findings imply that c-Fos may undergo cell cycle dependent phosphorylation, in which some kinases including Aurora-A play a role in catalyzing the post translational modification of c-Fos.
authors.affiliation: Graduate Institute of Biomedicine and Biomedical Technology, National Chi Nan University, Puli, Nantou, 545, Taiwan, ROC.
authors.forename: Chang-Tze Ricky
authors.initials: CT
authors.lastname: Yu
authors.forename: Jiunn-Chyi
authors.initials: JC
authors.lastname: Wu
authors.forename: Mei-Chih
authors.initials: MC
authors.lastname: Liao
authors.forename: Shih-Lan
authors.initials: SL
authors.lastname: Hsu
authors.forename: Chi-Ying F
authors.initials: CY
authors.lastname: Huang
mesh_terms: D064107:Aurora Kinase B; D064127:Aurora Kinases; D001483:Base Sequence; D002460:Cell Line; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D008938:Mitosis / Q000502:physiology*; D046912:Multiprotein Complexes; D010750:Phosphoproteins / Q000378:metabolism*; D011499:Protein Processing, Post-Translational; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D016760:Proto-Oncogene Proteins c-fos / Q000378:metabolism*; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000235:genetics; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D013379:Substrate Specificity
chemical_list: D046912:Multiprotein Complexes; D010750:Phosphoproteins; D016760:Proto-Oncogene Proteins c-fos; D034741:RNA, Small Interfering; D011993:Recombinant Fusion Proteins; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins; C576921:AURKB protein, human; D064107:Aurora Kinase B; D064127:Aurora Kinases; D017346:Protein Serine-Threonine Kinases