| First Author | Strakova J | Year | 2011 |
| Journal | Biochim Biophys Acta | Volume | 1811 |
| Issue | 10 | Pages | 617-25 |
| PubMed ID | 21736954 | Mgi Jnum | J:177611 |
| Mgi Id | MGI:5295547 | Doi | 10.1016/j.bbalip.2011.06.017 |
| Citation | Strakova J, et al. (2011) Involvement of CTP:phosphocholine cytidylyltransferase-beta2 in axonal phosphatidylcholine synthesis and branching of neurons. Biochim Biophys Acta 1811(10):617-25 |
| abstractText | In the brain, phosphatidylcholine (PC) is synthesized by the CDP-choline pathway in which the rate-limiting step is catalyzed by two isoforms of CTP:phosphocholine cytidylyltransferase (CT): CTalpha and CTbeta2. In mice, CTbeta2 mRNA is more highly expressed in the brain than in other tissues, and several observations suggest that CTbeta2 plays an important role in the nervous system. We, therefore, investigated the importance of CTbeta2 for PC synthesis as well as for axon formation, growth and branching of primary sympathetic neurons. We show that in cultured primary neurons nerve growth factor increases the amount of CTbeta2, but not CTalpha, mRNA and protein. The brains of mice lacking CTbeta2 had normal PC content despite having 35% lower CT activity than wild-type brains. CTbeta2 mRNA and protein are abundant in distal axons of mouse sympathetic neurons whereas CTalpha mRNA and protein were not detected. Moreover, CTbeta2 deficiency in distal axons reduced the incorporation of [(3)H]choline into PC by 95% whereas PC synthesis in cell bodies/proximal axons was unaltered. These data suggest that CTbeta2 is the major CT isoform involved in PC synthesis in axons. Axons of CTbeta2-deficient sympathetic neurons contained 32% fewer branch points than did wild-type neurons although the number of axons/neuron and the rate of axon extension were the same as in wild-type neurons. We conclude that in distal axons of primary sympathetic neurons CTbeta2 is a major contributor to PC synthesis and promotes axon branching, whereas CTalpha appears to be the major CT isoform involved in PC synthesis in cell bodies/proximal axons. |
