Phosphatidylcholine biosynthesis during neuronal differentiation and its role in cell fate determination.
Neuronal differentiation is characterized by neuritogenesis and neurite outgrowth, processes that are dependent on membrane biosynthesis. Thus, the production of phosphatidylcholine (PtdCho), the major membrane phospholipid, should be stimulated during neuronal differentiation. We demonstrate that during retinoic acid (RA)-induced differentiation of Neuro-2a cells, PtdCho synthesis was promoted by an ordered and sequential activation of choline kinase alpha (CK(alpha)) and choline cytidylyltransferase alpha (CCT(alpha)). Early after RA stimulation, the increase in PtdCho synthesis is mainly governed by the biochemical activation of CCT(alpha). Later, the transcription of CK(alpha)- and CCT(alpha)-encoding genes was induced. Both PtdCho biosynthesis and neuronal differentiation are dependent on ERK activation. A novel mechanism is proposed by which PtdCho biosynthesis is coordinated during neuronal differentiation. Enforced expression of either CK(alpha) or CCTalpha increased the rate of synthesis and the amount of PtdCho, and these cells initiated differentiation without RA stimulation, as evidenced by cell morphology and the expression of genes associated with neuritogenesis. The differentiation resulting from enforced expression of CCT(alpha) or CK(alpha) was dependent on persistent ERK activation. These results indicate that elevated PtdCho synthesis could mimic the RA signals and thus determine neuronal cell fate. Moreover, they could explain the key role that PtdCho plays during neuronal regeneration.
Departamento de Ciencias Biológicas, Facultad de Ciencias Bioquímicas y Farmacéuticas, Instituto de Biología Molecular y Celular de Rosario, Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad Nacional de Rosario, Suipacha 531, Rosario, Argentina.
Hebe
H
Marcucci
Luciana
L
Paoletti
Suzanne
S
Jackowski
Claudia
C
Banchio
D000818:Animals; D015153:Blotting, Western; D002454:Cell Differentiation / Q000187:drug effects; D045744:Cell Line, Tumor; D002797:Choline Kinase / Q000235:genetics; D019916:Choline-Phosphate Cytidylyltransferase / Q000235:genetics; D005455:Fluorescent Antibody Technique; D051379:Mice; D009474:Neurons / Q000166:cytology* / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D020411:Oligonucleotide Array Sequence Analysis; D010713:Phosphatidylcholines / Q000096:biosynthesis* / Q000502:physiology; D015398:Signal Transduction / Q000187:drug effects / Q000235:genetics; D014212:Tretinoin / Q000494:pharmacology
D010713:Phosphatidylcholines; D014212:Tretinoin; D002797:Choline Kinase; D019916:Choline-Phosphate Cytidylyltransferase