The plasma membrane Ca2+-ATPase isoform 4 is localized in lipid rafts of cerebellum synaptic plasma membranes
The plasma membrane Ca2+-ATPase isoform 4 is localized in lipid rafts of cerebellum synaptic plasma membranes
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DOI：
10.1074/jbc.m506950200
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发表时间：
2006-01-06
影响因子：
4.8
通讯作者：
Mata, AM
中科院分区：
文献类型：
--
作者：
Sepúlveda, MR;Berrocal-Carrillo, MB;Mata, AM
在这里，我们描述了协会的突触体质膜Ca 2 +-ATP酶（PMCA）从猪小脑与胆固醇/鞘磷脂丰富的膜结构域（筏）。PMCA 4仅定位于通过在冰冷的Brij 96提取物的Nycodenz密度梯度中浮选制备的筏中。这是证实了其与筏标志物胆固醇，神经节苷脂GM 1，和PrPC的共定位。其余的PMCA亚型中发现的洗涤剂可溶性馏分，与大多数的膜蛋白。活性测定证实了PMCA亚型在密度梯度中的双峰分布，PMCA 4的活性较低，钙调蛋白的刺激比其他亚型更大。通过提供有序的膜微环境，脂筏可能有助于PMCA 4与突触神经末梢上的离散功能位置处的参与Ca 2+信号传导的蛋白质的相互作用。
Here we describe the association of the synaptosomal plasma membrane Ca2+-ATPase (PMCA) from pig cerebellum with cholesterol/ sphingomyelin-rich membrane domains ( rafts). The PMCA4 was localized exclusively in rafts prepared by floatation in Nycodenz density gradients of ice- cold Brij 96 extracts. This was corroborated by its colocalization with the raft markers cholesterol, ganglioside GM1, and PrPC. The remaining PMCA isoforms were found in the detergent-soluble fractions, with the majority of the membrane proteins. Activity assays confirmed the bimodal distribution of the PMCA isoforms in the density gradient, with a lower activity for PMCA4 and greater stimulation by calmodulin than for the other isoforms. By providing an ordered membrane microenvironment, lipid rafts may contribute to the interaction of PMCA4 with proteins involved in Ca2+ signaling at discrete functional positions on the synaptic nerve terminals.