Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 1990 Oct;87(19):7541-5.
doi: 10.1073/pnas.87.19.7541.

Identification and preliminary characterization of protein-cysteine farnesyltransferase

Affiliations

Identification and preliminary characterization of protein-cysteine farnesyltransferase

V Manne et al. Proc Natl Acad Sci U S A. 1990 Oct.

Abstract

Ras proteins must be isoprenylated at a conserved cysteine residue near the carboxyl terminus (Cys-186 in mammalian Ras p21 proteins) in order to exert their biological activity. Previous studies indicate that an intermediate in the mevalonate pathway, most likely farnesyl pyrophosphate, is the donor of this isoprenyl group. Inhibition of mevalonate synthesis reverts the abnormal phenotypes induced by the mutant RAS2Val-19 gene in Saccharomyces cerevisiae and blocks the maturation of Xenopus oocytes induced by an oncogenic Ras p21 protein of human origin. These results have raised the possibility of using inhibitors of the mevalonate pathway to block the transforming properties of ras oncogenes. Unfortunately, mevalonate is a precursor of various end products essential to mammalian cells, such as dolichols, ubiquinones, heme A, and cholesterol. In this study, we describe an enzymatic activity(ies) capable of catalyzing the farnesylation of unprocessed Ras p21 proteins in vitro at the correct (Cys-186) residue. This farnesylating activity is heat-labile, requires Mg2+ or Mn2+ ions, is linear with time and with enzyme concentration, and is present in all mammalian cell lines and tissues tested. Gel filtration analysis of a partially purified preparation of protein farnesyltransferase revealed two peaks of activity at 250-350 kDa and 80-130 kDa. Availability of an in vitro protein farnesyltransferase assay should be useful in screening for potential inhibitors of ras oncogene function that will not interfere with other aspects of the mevalonate pathway.

PubMed Disclaimer

Similar articles

Cited by

References

    1. Anal Biochem. 1976 May 7;72:248-54 - PubMed
    1. Trends Biochem Sci. 1990 Apr;15(4):139-42 - PubMed
    1. Nature. 1984 Aug 16-22;310(5978):583-6 - PubMed
    1. Proc Natl Acad Sci U S A. 1984 Sep;81(17):5305-9 - PubMed
    1. Proc Natl Acad Sci U S A. 1984 Nov;81(22):6953-7 - PubMed