Regulation of platelet activating factor synthesis: modulation of 1-alkyl-2-lyso-sn-glycero-3-phosphocholine:acetyl-CoA acetyltransferase by phosphorylation and dephosphorylation in rat spleen microsomes.
Regulation of platelet activating factor synthesis: modulation of 1-alkyl-2-lyso-sn-glycero-3-phosphocholine:acetyl-CoA acetyltransferase by phosphorylation and dephosphorylation in rat spleen microsomes.
复制标题
血小板激活因子合成的调节：通过大鼠脾微粒体中的磷酸化和去磷酸化调节1-烷基-2-溶血-sn-甘油-3-磷酸胆碱：乙酰辅酶A乙酰转移酶。
DOI：
10.1016/s0006-291x(84)80182-5
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发表时间：
1984
影响因子：
3.1
通讯作者：
Lee,TC
中科院分区：
文献类型：
--
作者：
Lenihan,DJ;Lee,TC
1-烷基-2-溶血-sn-甘油-3-磷酸胆碱：乙酰辅酶A乙酰转移酶在血小板活化因子的生物合成中起重要的调节作用，血小板活化因子是一种有效的生物活性介质。我们测试的假设，乙酰转移酶的活性可能是由酶的磷酸化和去磷酸化调制。结果表明，在存在F−的情况下分离的微粒体中，大鼠脾脏中的乙酰转移酶活性是存在Cl−的情况下分离的微粒体中的乙酰转移酶活性的2- 3倍。微粒体乙酰转移酶可通过将在Cl−存在下分离的微粒体与ATP、Mg 2+和大鼠脾脏可溶性组分预孵育来激活。添加磷脂酰丝氨酸，二酰基甘油，再加上钙离子进一步增强活性。乙酰转移酶活性的增加被取消的激活的微粒体与碱性磷酸酶的治疗。相反，在碱性磷酸酶处理的微粒体中，乙酰转移酶的活性可以在有利于磷酸化的孵育条件下重新激活。因此，我们的研究结果表明，乙酰转移酶活性的调节可逆的激活/失活通过磷酸化/去磷酸化。
1-Alkyl-2-lyso-sn-glycero-3-phosphocholine:acetyl-CoA acetyltransferase plays an important regulatory role in the biosynthesis of platelet activating factor, a potent bioactive mediator. We tested the hypothesis that the activity of acetyltransferase may be modulated by enzymatic phosphorylation and dephosphorylation. The results showed that acetyltransferase activity in rat spleens was 2- to 3-fold higher in microsomes isolated in the presence of F−than in those isolated in the presence of Cl−. The microsomal acetyltransferase could be activated by preincubation of microsomes, isolated in the presence of Cl−, with ATP, Mg2+, and the soluble fraction from rat spleen. Addition of phosphatidylserine, diacylglycerols, plus Ca2+further enhanced the activity. The increase in the activity of acetyltransferase was abolished by treatment of the activated microsomes with alkaline phosphatase. Conversely, the activity of acetyltransferase can be reactivated in the alkaline phosphatase-treated microsomes with incubation conditions that favor phosphorylation. Therefore, our findings suggest that acetyltransferase activity is regulated by reversible activation/inactivation through phosphorylation/dephosphorylation.