title: Evolutionary pattern of angiosperm bZIP factors homologous to the maize Opaque2 regulatory protein.
abstract: Opaque2 (O2) is a bZIP transcriptional regulatory factor involved in the control of seed storage proteins synthesis as well as carbon and nitrogen metabolism during maize seed development. Phylogenetic analysis of a possible complete and nonredundant collection of angiosperm bZIP factors resulted in the identification of 20 angiosperm O2-homologues that defined what we call the O2 gene family. Members of the family share a highly conserved bZIP DNA binding domain and several other motifs which define important functional features. The O2 family was enriched by the identification of 25 new putative angiosperm O2 homologous genes in EST databases and in the rice genome. Based on parsimony analysis, the collection of O2 homologues was organized into one eudicot-monocot and three monocot groups of orthologous genes and two groups of eudicot genes. These results support a model of the evolution of the O2 family that involves two O2 homologous gene duplications before the separation of monocots and eudicots. Further expansion of O2 homologues resulted in at least three and one gene duplications in the monocot and eudicot lineages, respectively. O2 appears to have been the result of a monocot-specific gene duplication event, and the possibility that O2 represents a functional specialization restricted to monocots is suggested.
authors.affiliation: Centro de Biologia Molecular e Engenharia Genética, Universidade Estadual de Campinas, Cidade Universitaria "Zeferino Vaz,", Distrito Barão Geraldo, 13081-970, Campinas, SP, Brazil. mgavince@obelix.unicamp.br
authors.forename: Michel
authors.initials: M
authors.lastname: Vincentz
authors.forename: Claudia
authors.initials: C
authors.lastname: Bandeira-Kobarg
authors.forename: Luciane
authors.initials: L
authors.lastname: Gauer
authors.forename: Paulo
authors.initials: P
authors.lastname: Schlögl
authors.forename: Adilson
authors.initials: A
authors.lastname: Leite
mesh_terms: D000595:Amino Acid Sequence; D050976:Basic-Leucine Zipper Transcription Factors; D001665:Binding Sites; D017124:Conserved Sequence; D004247:DNA / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D019143:Evolution, Molecular; D051790:G-Box Binding Factors; D020440:Gene Duplication; D008969:Molecular Sequence Data; D005810:Multigene Family; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics*; D016415:Sequence Alignment; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism; D003313:Zea mays / Q000235:genetics*
chemical_list: D050976:Basic-Leucine Zipper Transcription Factors; D004268:DNA-Binding Proteins; D051790:G-Box Binding Factors; D010940:Plant Proteins; D014157:Transcription Factors; C067402:opaque-2 protein, Zea mays; D004247:DNA