title: The E2FD/DEL2 factor is a component of a regulatory network controlling cell proliferation and development in Arabidopsis.
abstract: An emerging view of plant cell cycle regulators, including the E2F transcription factors, implicates them in the integration of cell proliferation and development. Arabidopsis encodes six E2F proteins that can act as activators or repressors of E2F-responsive genes. E2FA, E2FB and E2FC interact with the retinoblastoma-like RBR protein and bind to DNA together with their DP partners. In contrast, E2FD, E2FE and E2FF (also known as DEL2, DEL1 and DEL3) are atypical E2Fs that possess duplicated DNA binding regions, lack trans-activating and RBR-binding domains and are believed to act as transcriptional inhibitors/repressors. E2FE/DEL1 has been shown to inhibit the endocycle and E2FF/DEL3 appears to control cell expansion but the role of E2FD/DEL2 has not been reported so far. In this study, we investigated the expression of E2FD/DEL2 and analysed the accumulation of its product. These studies revealed that E2FD/DEL2 accumulation is subject to negative post-translational regulation mediated by the plant hormone auxin. Moreover, the analysis of mutant and transgenic plants characterized by altered expression of E2FD/DEL2 has revealed that this atypical E2F can affect plant growth by promoting cell proliferation and repressing cell elongation. Overexpression of E2FD/DEL2 increased the expression of E2FA, E2FB and E2FE/DEL1 whereas its inactivation led to the up-regulation of genes encoding repressors of cell division. These results suggest that E2FD/DEL2 is part of a regulatory network that controls the balance between cell proliferation and development in Arabidopsis.
authors: Department of Genetics and Microbiology, University of Pavia, Via Ferrata 1, 27100, Pavia, Italy.
authors: Rosangela
authors: R
authors: Sozzani
authors: Caterina
authors: C
authors: Maggio
authors: Roberta
authors: R
authors: Giordo
authors: Elisabetta
authors: E
authors: Umana
authors: Jose Trinidad
authors: JT
authors: Ascencio-Ibañez
authors: Linda
authors: L
authors: Hanley-Bowdoin
authors: Catherine
authors: C
authors: Bergounioux
authors: Rino
authors: R
authors: Cella
authors: Diego
authors: D
authors: Albani
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D002453:Cell Cycle / Q000235:genetics; D049109:Cell Proliferation; D018744:DNA, Plant / Q000235:genetics; D050684:E2F Transcription Factors / Q000235:genetics / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D053263:Gene Regulatory Networks; D017343:Genes, Plant; D007210:Indoleacetic Acids / Q000378:metabolism; D008969:Molecular Sequence Data; D009154:Mutation; D030821:Plants, Genetically Modified; D011499:Protein Processing, Post-Translational
chemical_list: D029681:Arabidopsis Proteins; D018744:DNA, Plant; D050684:E2F Transcription Factors; D007210:Indoleacetic Acids