Replacement of the H-Ras farnesyl group by lipid analogues: implications for downstream processing and effector activation in Xenopus oocytes

In vivo experimental system using Xenopus laevis oocytes was conducted to analyze the structure-function relationship of the H-Ras farnesyl group for signal transduction. It was shown that farnesylation was necessary and sufficient to allow bacterially expressed H-Ras to induce oocyte maturation and activation of the MAPK cascade. Ras was rendered a hydrophobic center, enabling it to downstream processing enzymes resulting in membrane localization.