RESUMEN
Cyr61 is a secreted, heparin-binding, extracellular matrix-associated protein whose activities include the promotion of adhesion and chemotaxis, and the stimulation of fibroblast and endothelial cell growth. Many, if not all, of these activities of Cyr61 are mediated through interactions with integrins. We explore the role of Cyr61 in the early development of Xenopus laevis. Gain- and loss-of-function experiments show that Xcyr61 is required for normal gastrulation movements. This role is mediated in part through the adhesive properties of Xcyr61 and its related ability to modulate assembly of the extracellular matrix. In addition, Xcyr61 can, in a context-dependent manner, stimulate or inhibit signalling through the Wnt pathway. These properties of Xcyr61 provide a mechanism for integrating cell signalling, cell adhesion and cell migration during gastrulation.
Asunto(s)
Gástrula/citología , Proteínas Inmediatas-Precoces/genética , Péptidos y Proteínas de Señalización Intercelular/genética , Proteínas Proto-Oncogénicas/metabolismo , Xenopus laevis/embriología , Xenopus laevis/genética , Proteínas de Pez Cebra , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Proteínas Morfogenéticas Óseas/metabolismo , Adhesión Celular , Movimiento Celular , Proteína 61 Rica en Cisteína , Proteínas del Citoesqueleto/metabolismo , ADN Complementario/genética , Gástrula/efectos de los fármacos , Gástrula/metabolismo , Regulación del Desarrollo de la Expresión Génica , Proteoglicanos de Heparán Sulfato/metabolismo , Proteínas Inmediatas-Precoces/metabolismo , Péptidos y Proteínas de Señalización Intercelular/metabolismo , Datos de Secuencia Molecular , Oligodesoxirribonucleótidos Antisentido/genética , Oligodesoxirribonucleótidos Antisentido/farmacología , Homología de Secuencia de Aminoácido , Transducción de Señal , Transactivadores/metabolismo , Proteínas Wnt , Proteínas de Xenopus , Xenopus laevis/metabolismo , beta CateninaRESUMEN
Genetic experiments in bacteria have shown the suf operon is involved in iron homeostasis and the oxidative stress response. The sufB and sufC genes that always occur together in bacteria are also found in plants, and even the malaria parasite, associated with the plastid organelle. Although the suf operon is believed to encode an iron-dependent ABC-transporter there is no direct evidence. By immunolocalization we show here that SufB and SufC are associated with the membrane of Escherichia coli. We also present kinetic studies with a recombinant version of SufC from Thermotoga maritima that shows it is an ATPase and that it interacts with SufB in vitro.
