title: Characterization and expression analysis of the aspartic protease gene family of Cynara cardunculus L.
abstract: Cardosin A and cardosin B are two aspartic proteases mainly found in the pistils of cardoon Cynara cardunculus L., whose flowers are traditionally used in several Mediterranean countries in the manufacture of ewe's cheese. We have been characterizing cardosins at the biochemical, structural and molecular levels. In this study, we show that the cardoon aspartic proteases are encoded by a multigene family. The genes for cardosin A and cardosin B, as well as those for two new cardoon aspartic proteases, designated cardosin C and cardosin D, were characterized, and their expression in C. cardunculus L. was analyzed by RT-PCR. Together with cardosins, a partial clone of the cyprosin B gene was isolated, revealing that cardosin and cyprosin genes coexist in the genome of the same plant. As a first approach to understanding what dictates the flower-specific pattern of cardosin genes, the respective gene 5' regulatory sequences were fused with the reporter beta-glucuronidase and introduced into Arabidopsis thaliana. A subsequent deletion analysis of the promoter region of the cardosin A gene allowed the identification of a region of approximately 500 bp essential for gene expression in transgenic flowers. Additionally, the relevance of the leader intron of the cardosin A and B genes for gene expression was evaluated. Our data showed that the leader intron is essential for cardosin B gene expression in A. thaliana. In silico analysis revealed the presence of potential regulatory motifs that lay within the aforementioned regions and therefore might be important in the regulation of cardosin expression.
authors: Departamento de Biologia Molecular e Biotecnologia do Centro de Neurociências de Coimbra, Universidade de Coimbra, Coimbra, Portugal.
authors: Catarina
authors: C
authors: Pimentel
authors: Dominique
authors: D
authors: Van Der Straeten
authors: Euclides
authors: E
authors: Pires
authors: Carlos
authors: C
authors: Faro
authors: Claudina
authors: C
authors: Rodrigues-Pousada
mesh_terms: D017360:Arabidopsis / Q000235:genetics; D016282:Aspartic Acid Endopeptidases / Q000737:chemistry* / Q000235:genetics*; D001483:Base Sequence; D031942:Cynara / Q000201:enzymology*; D018506:Gene Expression Regulation, Plant; D007438:Introns / Q000502:physiology; D008969:Molecular Sequence Data; D010802:Phylogeny; D010940:Plant Proteins / Q000737:chemistry* / Q000235:genetics*; D011401:Promoter Regions, Genetic; D016415:Sequence Alignment
chemical_list: D010940:Plant Proteins; D016282:Aspartic Acid Endopeptidases; C097455:aspartic proteinases, Cynara cardunculus