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Effect of ATP Depletion on the Palmitoylation of Myelin Proteolipid Protein in Young and Adult Rats
Author(s) -
Bizzozero Oscar A.,
Sanchez Paul,
Tetzloff Sabine U.
Publication year - 1999
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1046/j.1471-4159.1999.0722610.x
Subject(s) - palmitoylation , proteolipid protein 1 , myelin , myelin proteolipid protein , myelin sheath , chemistry , microbiology and biotechnology , biochemistry , neuroscience , medicine , biology , myelin basic protein , central nervous system , enzyme , cysteine
The present study was designed to determine whether thepalmitoylation of the hydrophobic myelin proteolipid protein (PLP) isdependent on cellular energy. To this end, brain slices from 20‐ and60‐day‐old rats were incubated with [ 3 H]palmitate for 1 h in thepresence or absence of various metabolic poisons. In adult rats, theinhibition of mitochondrial ATP production with KCN (5 m M ),oligomycin (10 μ M ), or rotenone (10 μ M ) reduced theincorporation of [ 3 H]palmitate into fatty acyl‐CoA andglycerolipids by 50‐60%, whereas the labeling of PLP was unaltered. Incubationin the presence of rotenone (10 μ M ) plus NaF (5 m M )abolished the synthesis of acyl‐CoA and lipid palmitoylation, but theincorporation of [ 3 H]palmitate into PLP was still not different from that in controls. In rapidly myelinating animals, the inhibition of both mitochondrial electron transport and glycolysis obliterated the palmitoylation of lipids but reduced that of PLP by only 40%. PLP acylation was reduced to a similar extent when slices were incubated for up to 3 h, indicating that exogenously added palmitate is incorporated into PLP by ATP‐dependent and ATP‐independent mechanisms. Determination of the number of PLP molecules modified by each of these reactions during development suggests that the ATP‐dependent process is important during the formation and/or compaction of the myelin sheath, whereas the ATP‐independent mechanism is likely to play a role in myelin maintenance, perhaps by participating in the periodic repair of thioester linkages between the fatty acids and the protein.