Nerve growth factor stimulates phospholipid methylation in growing neurites.
Cultures of neurons from rat superior cervical ganglia were deprived of nerve growth factor, loaded with [methyl-3H]methionine, and then challenged with nerve growth factor for different periods of time. Growing neurites and perikarya were separated microsurgically and extracted with chloroform/methanol. Lipid-incorporated radioactivity in the extracts was measured and expressed on the basis of the amount of phospholipid present. The methylated species in the neurite fraction were identified by thin-layer chromatography as mono-, di-, and trimethylphosphatidylethanolamine (phosphatidylcholine). Furthermore, a small peak of lysophosphatidylcholine was detected. In the neurites, but not in the perikarya, phospholipid methylation was found to reach a peak at 10 sec after onset of stimulation. Stimulated levels were at least 4 times higher than levels of unstimulated controls. The peak was followed by rapid decline of phospholipid-incorporated radioactivity. Our result indicates that phospholipid methylation is part of a nerve-growth-factor-activated secondary messenger system in growing sympathetic neurites. The potential significance of this conclusion for directed neuritic growth and membrane expansion is discussed.
D000818:Animals; D002118:Calcium / Q000502:physiology; D002454:Cell Differentiation / Q000187:drug effects; D002462:Cell Membrane / Q000378:metabolism; D002478:Cells, Cultured; D008563:Membrane Lipids / Q000378:metabolism*; D008745:Methylation; D008780:Methyltransferases / Q000378:metabolism*; D009414:Nerve Growth Factors / Q000494:pharmacology*; D009474:Neurons / Q000378:metabolism* / Q000648:ultrastructure; D050918:Phosphatidylethanolamine N-Methyltransferase; D010743:Phospholipids / Q000378:metabolism; D051381:Rats
D008563:Membrane Lipids; D009414:Nerve Growth Factors; D010743:Phospholipids; D008780:Methyltransferases; D050918:Phosphatidylethanolamine N-Methyltransferase; D002118:Calcium