QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

Help viewing high resolution images Return to article

Fig. 2. Post-translational processing of yeast Ras at the ER. Ras is initially synthesized as a soluble precursor on soluble ribosomes and subsequently undergoes a series of processing events. The first step, farnesylation, is carried out by Ram1p/Ram2p, which modifies Ras and escorts it to the ER membrane. Farnesylated Ras is then proteolyzed by the CaaX protease Rce1, which removes the C-terminal -aaX sequence. The Ste14p carboxylmethyltransferase then methylates the farnesylated cysteine. Finally, the Erf2p/Erf4p PAT palmitoylates Ras at a cysteine residue adjacent to the farnesylated cysteine. The fully processed Ras protein is competent for transport to the plasma membrane. The topology model of Ste14p is from Romano and Michaelis (Romano and Michaelis, 2001), whereas the membrane topology of Rce1p, Erf2p and Erf4p is speculative and inferred from hydropathy plots. The DHHC-CRD domain of Erf2 is indicated by a purple cylinder.

Return to article