TY - JOUR
T1 - Nonidentical subunits of p21H-ras farnesyltransferase
T2 - Peptide binding and farnesyl pyrophosphate carrier functions
AU - Reiss, Yuval
AU - Seabra, Miguel C.
AU - Armstrong, Scott A.
AU - Slaughter, Clive A.
AU - Goldstein, Joseph L.
AU - Brown, Michael S.
PY - 1991
Y1 - 1991
N2 - The protein farnesyltransferase purified from rat brain contains two nonidentical subunits, α and β. The holoenzyme forms a stable complex with [3H]farnesyl pyrophosphate (FPP) that can be isolated by gel filtration. The [3H]FPP is not covalently bound to the enzyme; it is released unaltered when the enzyme is denatured. When incubated with an acceptor such as p21H-ras, the complex transfers [3H]farnesyl from the bound [3H]FPP to the ras protein. This transfer is not sensitive to dilution by unbound FPP, suggesting that the [3H]FPP is bound at a site that leads to direct transfer to the p21H-ras acceptor. Cross-linking studies show that the p21H-ras binds to the lower molecular weight subunit (β-subunit), raising the possibility that the [3H]FPP binds to the α-subunit. If this suggestion can be confirmed, it would invoke a reaction mechanism in which the α-subunit acts as a prenyl pyrophosphate carrier that delivers FPP to p21H-ras which is bound to the β-subunit.
AB - The protein farnesyltransferase purified from rat brain contains two nonidentical subunits, α and β. The holoenzyme forms a stable complex with [3H]farnesyl pyrophosphate (FPP) that can be isolated by gel filtration. The [3H]FPP is not covalently bound to the enzyme; it is released unaltered when the enzyme is denatured. When incubated with an acceptor such as p21H-ras, the complex transfers [3H]farnesyl from the bound [3H]FPP to the ras protein. This transfer is not sensitive to dilution by unbound FPP, suggesting that the [3H]FPP is bound at a site that leads to direct transfer to the p21H-ras acceptor. Cross-linking studies show that the p21H-ras binds to the lower molecular weight subunit (β-subunit), raising the possibility that the [3H]FPP binds to the α-subunit. If this suggestion can be confirmed, it would invoke a reaction mechanism in which the α-subunit acts as a prenyl pyrophosphate carrier that delivers FPP to p21H-ras which is bound to the β-subunit.
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M3 - Article
C2 - 2037606
AN - SCOPUS:0025923649
SN - 0021-9258
VL - 266
SP - 10672
EP - 10677
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 16
ER -