Abstract

Isoprenylated protein methyltransferase, the enzyme which catalyzes the reversible methylation of signal transducing G-proteins was studied in nine brain regions of the rat brain using S-farnesyl cysteine analogs as substrates. Enzyme activity, as determined with N-acetyl-S-farnesyl-L-cysteine (AFC) was found in the nuclear, synaptosomal and microsomal fractions of all brain regions but not in the cytosol. The enzyme is a unique methyltransferase with respect to its brain distribution. The rank order of activity of the enzyme is cerebellum ⪢ midbrain > medulla > forebrain regions, where activites in cerebellar synaptosomal and nuclear fractions (28-32 pmol AFC [methyl-3H]ester formed/min/mg prot) are 20 to 30 times higher than those of the corresponding fraction of the forebrain regions. This distribution is reminiscent of that of neurotransmitter receptors and signal transduction molecules and suggests a regulatory role for the enzyme, particularly in the cerebellum.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.