Synthesis of phosphatidylserine by base exchange in Triton-insoluble floating fractions from rat cerebellum
Synthesis of phosphatidylserine by base exchange in Triton-insoluble floating fractions from rat cerebellum
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DOI：
10.1111/j.1471-4159.2007.04783.x
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发表时间：
2007-11-01
影响因子：
4.7
通讯作者：
Mozzi, Rita
中科院分区：
文献类型：
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作者：
Buratta, Sandra;Felicetti, Michela;Mozzi, Rita
磷脂酰丝氨酸（PS）是蛋白激酶C（PKC）活性所必需的，它是在哺乳动物组织中通过游离丝氨酸与膜甘油磷脂中的氮碱基交换而合成的。蛋白激酶C与其他参与信号转导的分子一样，存在于脂筏中，被认为是分子信号转导的平台。膜微区富含筏的成分，可以分离的基础上，他们在Triton X-100在4 ℃和蔗糖密度梯度的低密度的不溶性。这项研究表明，存在的丝氨酸碱基交换酶（SBEE）在Triton不溶性浮动馏分含有相关的PKC。使用两个馏分的洗涤剂抗性膜从大鼠小脑，我们观察到SBEE活性和膜相关的PKC的水平之间的相关性。这表明SBEE在PKC结合区合成PS，参与信号转导。SBEE的能力，利用不仅丝氨酸，而且乙醇胺，作为自由交换碱，表明在位置PS浓度的调制机制。
Phosphatidylserine (PS), which is synthesized in mammalian tissues by the exchange between free serine and the nitrogen bases present in membrane glycerophospholipids, is strictly required for protein kinase C (PKC) activity. PKC, as other molecules involved in signal transduction, is present in lipid rafts, considered as a platform for molecular signaling. Membrane microdomains enriched in components of rafts can be isolated on the basis of their insolubility in Triton X-100 at 4 degrees C and their low density in sucrose density gradient. This study demonstrates the existence of serine base exchange enzyme (SBEE) in Triton-insoluble floating fractions containing associated PKC. Using two fractions of detergent-resistant membranes from rat cerebellum, we observed a correlation between the level of SBEE activity and that of membrane-associated PKC. This suggests that SBEE, synthesizing PS in the binding area for PKC, participates to signal transduction. The capability of SBEE to utilize not only serine but also ethanolamine, as free exchanging base, suggests a mechanism for modulating in loco PS concentration.