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Methylation and proteolysis are essential for efficient membrane binding of prenylated p21K‐ras(B).
Author(s) -
Hancock J. F.,
Cadwallader K.,
Marshall C. J.
Publication year - 1991
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1002/j.1460-2075.1991.tb07992.x
Subject(s) - hematology , prenylation , methylation , biology , medicine , genetics , biochemistry , gene , enzyme
Plasma membrane targeting of p21K‐ras(B) requires a CAAX motif and a polybasic domain. The CAAX box directs a triplet of post‐translational modifications: farnesylation, proteolysis of the AAX amino acids and methylesterification. These modifications are closely coupled in vivo. However, in vitro translation of mRNA in rabbit reticulocyte lysates produces p21K‐ras(B) proteins which are arrested in processing after farnesylation. Intracellular membranes are then required both for proteolytic removal of the AAX amino acids and methylesterification of farnesylated p21K‐ras(B). Binding of p21K‐ras(B) to plasma membranes in vitro can then be shown to depend critically on AAX proteolysis and methylesterification since p21K‐ras(B) which is farnesylated, but not methylated, binds inefficiently to membranes.