Effect of the 1-methyl-4-phenylpyridinium ion on phosphorylation of tyrosine hydroxylase in rat pheochromocytoma PC12h cells
Review articleOpen access
1988/06/29 Full-length article DOI: 10.1016/0304-3940(88)90383-7
Journal: Neuroscience Letters
AbstractEffects of the 1-methyl-4-phenylpyridinium ion (MPP+) on DOPA formation and phosphorylation of tyrosine hydroxylase (TH) of rat pheochromocytoma PC12h cells were examined after the cells were cultured with MPP+. DOPA formed from endogenous tyrosine in PC12h cells after a 3-day culture with 100 μM MPP+ was decreased to less than 50% as compared to that in the control cells cultured without MPP+. Kinetical study showed that two apparent forms of TH with different Km existed in the cells cultured with 100 μM MPP+ but one form in that of control. Incorporation of radioactive phosphate into TH molecule was also reduced to 50% of its control value following a 3-day exposure to 100 μM MPP+. These results suggest that MPP+ acutely inhibits the phosphorylation of TH to decrease cellular DOPA formation.
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