Effects of monensin on posttranslational processing of myelin proteins.
Rat brain slices were incubated with [3H]palmitic acid and [14C]glycine to label the lipid and protein moieties, respectively, of myelin proteolipid protein (PLP). The effects of monensin on posttranslational processing of proteins were examined by measuring the appearance of [14C]glycine- and [3H]palmitate-labeled proteins in myelin and myelin-like fractions. At 0.01 and 0.10 microM, monensin did not appreciably affect total lipid or protein synthesis; higher concentrations caused increased inhibition. Monensin at 0.10 microM markedly decreased the appearance of [14C]glycine-labeled PLP in myelin, but had little effect on the 14C basic proteins or the incorporation of [3H]palmitic acid into total or myelin PLP. The same relative effect was apparent at higher monensin concentrations. In the myelin-like fraction, monensin at 0.10 microM also depressed entry of [14C]glycine into protein comigrating with PLP, and again had no effect on incorporation of [3H]palmitic acid. In addition, monensin increased the [3H]palmitate label associated with two high-molecular-weight proteins in the myelin-like fraction with no concomitant increase in [14C]glycine label.
D000818:Animals; D001921:Brain / Q000187:drug effects / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D005663:Furans / Q000494:pharmacology*; D005998:Glycine / Q000378:metabolism; D007700:Kinetics; D008297:Male; D008985:Monensin / Q000494:pharmacology*; D009185:Myelin Proteins / Q000235:genetics* / Q000302:isolation & purification; D009186:Myelin Sheath / Q000187:drug effects / Q000378:metabolism*; D019308:Palmitic Acid; D010169:Palmitic Acids / Q000378:metabolism; D011499:Protein Processing, Post-Translational / Q000187:drug effects*; D051381:Rats; D011919:Rats, Inbred Strains; D013347:Subcellular Fractions / Q000378:metabolism
D005663:Furans; D009185:Myelin Proteins; D010169:Palmitic Acids; D019308:Palmitic Acid; D008985:Monensin; D005998:Glycine