title: The E2F family of transcription factors from Arabidopsis thaliana. Novel and conserved components of the retinoblastoma/E2F pathway in plants.
abstract: The E2F transcription factors are key components of the cyclin D/retinoblastoma/E2F pathway. Here we demonstrate that Arabidopsis thaliana contains six functional AtE2F genes that are all expressed in cell suspension culture but show different patterns of expression during cell cycle progression. According to their structural and functional features, the six AtE2Fs can be divided into two distinct groups; although the three members of the first group, AtE2Fa, AtE2Fb and AtE2Fc, possess all the conserved domains found in other plant and animal E2Fs, the remaining AtE2Fs are novel proteins, which reveal a duplication of the DNA binding domain but lack any other conserved region. Furthermore, the AtE2Fs of the first group are functional transcription factors that in association with AtDP proteins can recognize specifically an E2F cis-element and can transactivate an E2F-responsive reporter gene in plant cells. In contrast, the AtE2Fs of the second group can bind specifically the E2F site without interacting with DP partners but cannot activate gene expression and, instead, are able to inhibit E2F-dependent activation of gene expression in Arabidopsis cells. These findings suggest distinctive roles for the plant E2F proteins and point to a complex concerted regulation of E2F-dependent gene expression in plant cells.
authors.affiliation: Department of Genetics and Microbiology, University of Pavia, Via Ferrata 1, 27100 Pavia, Italy.
authors.forename: Luisa
authors.initials: L
authors.lastname: Mariconti
authors.forename: Barbara
authors.initials: B
authors.lastname: Pellegrini
authors.forename: Rita
authors.initials: R
authors.lastname: Cantoni
authors.forename: Rebecca
authors.initials: R
authors.lastname: Stevens
authors.forename: Catherine
authors.initials: C
authors.lastname: Bergounioux
authors.forename: Rino
authors.initials: R
authors.lastname: Cella
authors.forename: Diego
authors.initials: D
authors.lastname: Albani
mesh_terms: D000595:Amino Acid Sequence; D016590:Aphidicolin / Q000494:pharmacology; D017360:Arabidopsis / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000378:metabolism; D001665:Binding Sites; D018797:Cell Cycle Proteins; D017124:Conserved Sequence; D004247:DNA / Q000378:metabolism; D018076:DNA, Complementary / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism; D019281:Dimerization; D050684:E2F Transcription Factors / Q000737:chemistry / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D016193:G1 Phase; D016195:G2 Phase; D008969:Molecular Sequence Data; D005810:Multigene Family; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000378:metabolism; D016160:Retinoblastoma Protein / Q000737:chemistry / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid; D014157:Transcription Factors / Q000737:chemistry / Q000378:metabolism*; D015533:Transcriptional Activation
chemical_list: D029681:Arabidopsis Proteins; D018797:Cell Cycle Proteins; D018076:DNA, Complementary; D004268:DNA-Binding Proteins; D050684:E2F Transcription Factors; C514752:E2FC protein, Arabidopsis; D004791:Enzyme Inhibitors; D011994:Recombinant Proteins; D016160:Retinoblastoma Protein; D014157:Transcription Factors; D016590:Aphidicolin; D004247:DNA