title: The newly characterized Pl-jun is specifically expressed in skeletogenic cells of the Paracentrotus lividus sea urchin embryo.
abstract: Growing evidence suggests that the transcription factors belonging to the Jun family are involved in many important cellular events, such as the control of bone development in mammalians. We have characterized, for the first time, a member of the Jun family from embryos of the sea urchin Paracentrotus lividus. The Pl-jun protein sequence includes all the functional domains characteristic of members of the Jun family (i.e. the basic leucine zipper, the basic DNA-binding and the c-Jun N-terminal kinase docking-like domains), which are evolutionarily conserved. Moreover, all the key serine and threonine residues, which are phosphorylation targets for different kinases necessary for jun activation, appear to be well preserved. A model of the monomeric protein provides a simulation of the three-dimensional structure and shows the potential sites for dimerization and DNA binding. Pl-jun mRNA is expressed in the unfertilized egg and throughout sea urchin embryo development. As the development proceeds, Pl-jun mRNA becomes exclusively expressed in the skeletogenic cells. Intriguingly, these cells contain significant amounts of the phosphorylated active protein entirely localized into their nuclei. These findings strengthen our hypothesis that suggests an active role for Pl-jun in skeletogenic cells, thus indicating that this transcription factor is a novel component of the gene regulatory networks controlling skeletogenesis. Database: Nucleotide sequence data have been deposited in the EMBL databases under the accession number: HE817756.
authors.affiliation: Institute of Biomedicine and Molecular Immunology 'A. Monroy', National Research Council, Palermo, Italy.
authors.forename: Roberta
authors.initials: R
authors.lastname: Russo
authors.forename: Annalisa
authors.initials: A
authors.lastname: Pinsino
authors.forename: Caterina
authors.initials: C
authors.lastname: Costa
authors.forename: Rosa
authors.initials: R
authors.lastname: Bonaventura
authors.forename: Valeria
authors.initials: V
authors.lastname: Matranga
authors.forename: Francesca
authors.initials: F
authors.lastname: Zito
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002356:Cartilage / Q000196:embryology*; D004625:Embryo, Nonmammalian / Q000378:metabolism; D047108:Embryonic Development; D018507:Gene Expression Regulation, Developmental; D048031:JNK Mitogen-Activated Protein Kinases / Q000378:metabolism*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D038081:Organogenesis / Q000502:physiology*; D047328:Paracentrotus / Q000196:embryology*; D010766:Phosphorylation; D010802:Phylogeny; D012333:RNA, Messenger / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics
chemical_list: D012333:RNA, Messenger; D014157:Transcription Factors; D048031:JNK Mitogen-Activated Protein Kinases
keywords: AP-1 transcription factor; development; phosphorylation; phylogenetics; primary mesenchyme cells