TY - JOUR AU - Beaujois, Rémy AU - Riquet, Franck AU - Cailliau, Katia AU - Browaeys-Poly, Edith AU - Russo, Christophe AU - Blossey, Ralf AU - Vicogne, Dorothée AU - Marin, Matthieu AU - Lescuyer-Rousseau, Arlette AU - Vilain, Jean-Pierre AU - Bodart, Jean-François PY - 2013/01/30 Y2 - 2024/03/29 TI - Ultrasensitive MAPK/Erk activation in absence of protein synthesis in Xenopus oocytes JF - MAP Kinase JA - MAP Kinase VL - 2 IS - 1 SE - Original Articles DO - 10.4081/mk.2013.e2 UR - https://www.pagepressjournals.org/mk/article/view/mk.2013.e2 SP - e2 AB - The mitogen-activated protein kinase (MAPK) cascade in <em>Xenopus</em> oocytes exhibits an all-or-none, ultrasensitive response, which is believed to result from a positive feed-back loop. Here we describe a context where 1,10-phenanthroline slowly, but strongly, activates MAPK while it impairs protein synthesis in a zincdependent manner, abolishing any feed-back loop. The induced-MAPK response was found to be strongly ultrasensitive. We argue that underlying this behaviour is a regulation motif akin to a feed-forward loop acting <em>in vivo</em>. ER -