RESUMO
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.
Assuntos
Gástrula/citologia , Proteínas Imediatamente Precoces/genética , Peptídeos e Proteínas de Sinalização Intercelular/genética , Proteínas Proto-Oncogênicas/metabolismo , Xenopus laevis/embriologia , Xenopus laevis/genética , Proteínas de Peixe-Zebra , Sequência de Aminoácidos , Animais , Sequência de Bases , Proteínas Morfogenéticas Ósseas/metabolismo , Adesão Celular , Movimento Celular , Proteína Rica em Cisteína 61 , Proteínas do Citoesqueleto/metabolismo , DNA Complementar/genética , Gástrula/efeitos dos fármacos , Gástrula/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Proteoglicanas de Heparan Sulfato/metabolismo , Proteínas Imediatamente Precoces/metabolismo , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Dados de Sequência Molecular , Oligodesoxirribonucleotídeos Antissenso/genética , Oligodesoxirribonucleotídeos Antissenso/farmacologia , Homologia de Sequência de Aminoácidos , Transdução de Sinais , Transativadores/metabolismo , Proteínas Wnt , Proteínas de Xenopus , Xenopus laevis/metabolismo , beta CateninaRESUMO
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.
