RESUMEN
Apterous is a LIM-homeodomain protein that confers dorsal compartment identity in Drosophila wing development. Apterous activity requires formation of a complex with a co-factor, Chip/dLDB. Apterous activity is regulated during wing development by dLMO, which competes with Apterous for complex formation. Here, we present evidence that complex formation between Apterous, Chip and DNA stabilizes Apterous protein in vivo. We also report that a difference in the ability of Chip to bind the LIM domains of Apterous and dLMO contributes to regulation of activity levels in vivo.
Asunto(s)
Proteínas de Drosophila , Proteínas de Homeodominio/metabolismo , Proteínas Nucleares/metabolismo , Factores de Transcripción/metabolismo , Alas de Animales/crecimiento & desarrollo , Animales , Unión Competitiva , Cisteína Endopeptidasas/metabolismo , Drosophila , Regulación del Desarrollo de la Expresión Génica , Proteínas de Homeodominio/química , Proteínas de Homeodominio/genética , Proteínas con Homeodominio LIM , Larva , Modelos Genéticos , Complejos Multienzimáticos/metabolismo , Proteínas Nucleares/química , Proteínas Nucleares/genética , Complejo de la Endopetidasa Proteasomal , Unión Proteica , Estructura Terciaria de Proteína , Proteínas Recombinantes de Fusión/metabolismo , Factores de Transcripción/química , Factores de Transcripción/genéticaRESUMEN
Drosophila limbs develop from imaginal discs that are subdivided into compartments. Dorsal-ventral subdivision of the wing imaginal disc depends on apterous activity in dorsal cells. Apterous protein is expressed in dorsal cells and is responsible for (1) induction of a signaling center along the dorsal-ventral compartment boundary (2) establishment of a lineage restriction boundary between compartments and (3) specification of dorsal cell fate. Here, we report that the homeobox gene msh (muscle segment homeobox) acts downstream of apterous to confer dorsal identity in wing development.
Asunto(s)
Proteínas de Drosophila , Proteínas de Homeodominio/metabolismo , Proteínas de Insectos/metabolismo , Transducción de Señal/fisiología , Factores de Transcripción/metabolismo , Alelos , Animales , Tipificación del Cuerpo/fisiología , Diferenciación Celular , Drosophila melanogaster/genética , Drosophila melanogaster/crecimiento & desarrollo , Proteínas de Homeodominio/genética , Proteínas de Insectos/genética , Proteínas con Homeodominio LIM , Mutagénesis , Factores de Transcripción/genética , Alas de Animales/citología , Alas de Animales/crecimiento & desarrolloRESUMEN
Mechanisms to segregate cell populations play important roles in tissue patterning during animal development. Rhombomeres and compartments in the ectoderm and imaginal discs of Drosophila are examples in which initially homogenous populations of cells come to be separated by boundaries of lineage restriction. Boundary formation depends in part on signaling between the distinctly specified cell populations that comprise compartments and in part on formation of affinity boundaries that prevent intermingling of these cell populations. Here, we present evidence that two transmembrane proteins with leucine-rich repeats, known as Capricious and Tartan, contribute to formation of the affinity boundary between dorsal and ventral compartments during Drosophila wing development.
Asunto(s)
Proteínas de Drosophila , Drosophila/crecimiento & desarrollo , Drosophila/genética , Proteínas de la Membrana/fisiología , Alas de Animales/crecimiento & desarrollo , Animales , Adhesión Celular , Supervivencia Celular , Eliminación de Gen , Heterocigoto , Hormonas de Insectos/genética , Hormonas de Insectos/fisiología , Proteínas de Insectos/genética , Proteínas de Insectos/fisiología , Proteínas de la Membrana/genética , Alas de Animales/anatomía & histología , Alas de Animales/citologíaRESUMEN
E2F is a family of transcription factors that regulates the cell cycle. It is widely accepted that E2F-mediated transactivation of a set of genes is the critical activity that governs cellular progression through G(1) into S phase. In contrast to this hypothesis, we demonstrate that E2F actually suppresses the onset of S phase in two cell types when the cells are arrested by gamma irradiation. Our findings indicate that in these cells, the critical event triggering progression from G(0)/G(1) arrest into S phase is the release of E2F-mediated transrepression of cell cycle genes, not transactivation by E2F. Furthermore, our data suggest that E2F-mediated transactivation is not necessary for the G(1)/S-phase transition in these cells.