Occurrence of an Unusual Phospholipid, Phosphatidyl-l-threonine, in Cultured Hippocampal Neurons
Occurrence of an Unusual Phospholipid, Phosphatidyl-l-threonine, in Cultured Hippocampal Neurons
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培养的海马神经元中存在不寻常的磷脂，磷脂酰-l-苏氨酸
DOI：
10.1074/jbc.273.31.19363
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发表时间：
1998
期刊：
影响因子：
--
通讯作者：
Y. Hirabayashi
中科院分区：
文献类型：
--
作者：
J. Mitoma;T. Kasama;S. Furuya;Y. Hirabayashi
我们最近报道，在无血清和神经胶质细胞的培养条件下，星形胶质细胞释放的 1-丝氨酸支持海马神经元的存活和神经突发生（Mitoma, J.、Furuya, S. 和 Hirabayashi, Y. (1998) Neurosci. Res. 30, 195–199）。在这项研究中，我们发现海马神经元中磷脂酰-L-丝氨酸（PS）和鞘脂的合成需要外源性L-丝氨酸。当海马神经元维持在无星形胶质细胞的条件下时，在缺乏外部L-丝氨酸或甘氨酸的情况下，神经元中的鞘脂和磷脂酰-L-丝氨酸的水平大大降低。相反，在 TLC 上，一种新型磷脂出现在 PS 之前。通过薄层色谱印迹/负二次离子质谱和氨基酸分析，确定这种新型脂质为磷脂酰-L-苏氨酸。对大鼠脑微粒体的生化研究表明，磷脂酰-L-苏氨酸是由参与PS合成的碱基交换酶合成的，亲和力低得多，即大约1 150个L-丝氨酸。培养基中添加 L-丝氨酸或甘氨酸可恢复神经元中 PS 和鞘脂的合成。这些观察结果表明，在星形胶质细胞不存在的情况下，海马神经元需要外源 1-丝氨酸来合成 PS 和鞘脂，并表明星形胶质细胞通过提供 1-丝氨酸有助于神经元脂质合成。
We have recently reported thatl-serine released from astroglial cells supports the survival and neuritogenesis of hippocampal neurons under a serum- and glia-free culture condition (Mitoma, J., Furuya, S., and Hirabayashi, Y. (1998) Neurosci. Res. 30, 195–199). In this study, we show that exogenous l-serine is required for the synthesis of phosphatidyl-l-serine (PS) and sphingolipids in hippocampal neurons. When hippocampal neurons were maintained under an astroglial cell-free condition, the levels of sphingolipids and phosphatidyl-l-serine in the neurons were greatly reduced in the absence of external l-serine or glycine. Instead, a novel phospholipid appeared just ahead of PS on TLC. This novel lipid was determined to be phosphatidyl-l-threonine by TLC blotting/negative secondary ion mass spectrometry and amino acid analysis. Biochemical studies on rat brain microsomes have indicated that phosphatidyl-l-threonine is synthesized by the base exchange enzyme that is involved in PS synthesis with much lower affinity, that is, approximately 1 150 of l-serine. Addition of l-serine or glycine to the culture medium restored the synthesis of PS and sphingolipids in the neurons. These observations show that hippocampal neurons require exogenousl-serine for the synthesis of PS and sphingolipids in the absence of astroglial cells and suggested that astroglial cells contribute to neuronal lipid synthesis through the supply ofl-serine.
lyso-GM3（II3Neu5Ac 乳糖基鞘氨醇）、de-N-乙酰基-GM3（II3NeuNH2 乳糖基 Cer）和相关化合物的合成和表征。
影响因子：
3.1
作者：
Nores,GA;Hanai,N;Levery,SB;Eaton,HL;Salyan,EK;Hakomori,S
通讯作者：
Hakomori,S