Farnesyl protein transferase (FPT) activity was measured in rat liver subce
llular fractions by using an unspecific acceptor for the farnesyl groups. T
he highest specific activity was found in mitochondria and it exceeded that
of the microsomes three-fold, Considerably lower specific activities were
found in the nuclei and cytosol, Further subfractionation revealed that the
mitochondrial FPT activity is located in the matrix. The beta-subunit of t
he mitochondrial enzyme has an apparent molecular mass of 46 kDa, which is
similar to its cytosolic counterpart. The results suggest that protein farn
esylation can take place in a number of subcellular organelles. (C) 1999 Fe
deration of European Biochemical Societies.