Bombyx mori Ras proteins BmRas1, BmRas2 and BmRas3 are neither farnesylated nor palmitoylated but are geranylgeranylated.
The lipid modifications which occur on Bombyx mori Ras proteins BmRas1, BmRas2 and BmRas3 were studied by metabolic labelling in an insect cell-free protein synthesis system and in a baculovirus expression system, using specific inhibitors of protein prenylation and protein palmitoylation. In addition, the subcellular localization of BmRas proteins was examined using EGFP fusion proteins of constitutively active forms of BmRas proteins transiently expressed in Sf9 cells. As a result, it was revealed that the three B. mori Ras proteins BmRas1, BmRas2 and BmRas3 are neither farnesylated nor palmitoylated but are geranylgeranylated for localization to the plasma membrane of insect cells. Thus, the mechanism of membrane binding of insect Ras proteins is quite different from that reported for mammalian Ras proteins.
Moriya
K
K
Applied Molecular Bioscience, Graduate School of Medicine, Yamaguchi University, Yamaguchi, Japan.
Tsubota
T
T
Ishibashi
N
N
Yafune
A
A
Suzuki
T
T
Kobayashi
J
J
Shiotsuki
T
T
Utsumi
T
T
D000595:Amino Acid Sequence; D000818:Animals; D016367:Baculoviridae / Q000235:genetics; D012831:Bombyx / Q000166:cytology / Q000378:metabolism*; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D002474:Cell-Free System; D019143:Evolution, Molecular; D005822:Genetic Vectors / Q000235:genetics; D006801:Humans; D019476:Insect Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D054878:Lipoylation; D008969:Molecular Sequence Data; D054876:Prenylation; D014176:Protein Biosynthesis; D021381:Protein Transport; D013194:Staining and Labeling; D018631:ras Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
D019476:Insect Proteins; D018631:ras Proteins