XRASGRP2 is essential for blood vessel formation during Xenopus development

• Autores: Kan Suzuki, Shuji Takahashi, Yoshikazu Haramoto, Yasuko Onuma, Kentaro Nagamine, Koji Okabayashi, Kouhei Hashizume, Tadashi Iwanaka, Makoto Asashima
• Localización: International journal of developmental biology, ISSN 0214-6282, Vol. 54, Nº. 4, 2010, págs. 609-615
• Idioma: inglés
• Texto completo no disponible (Saber más ...)
• Resumen

  • Ras guanyl nucleotide-releasing protein 2 (RASGRP2), one of the Ras guanine exchange factors, is implicated as a critical regulator of inside-out integrin activation in human lymphocytes, neutrophils and platelets. However, the activities of this protein in endothelial cells remain unclear. In the current study, we identify a physiological function in blood vessel formation for XRASGRP2, which is the Xenopus ortholog of mammalian RASGRP2. XRASGRP2 over-expression induced ectopic vascular formation, and XRASGRP2-knockdown embryos showed delayed vascular development. We also investigated the upstream signaling of XRASGRP2 in endothelium formation. XRASGRP2 expression was up-regulated in the presence of VEGF-A and down-regulated following VEGF-A depletion. XRASGRP2 knockdown abolished the ectopic induction of endothelial cells by VEGF-A in the posterior ventral blood island. These results suggest that XRASGRP2 is essential for vascular formation during Xenopus development.