Differential distribution of proteins and lipids in detergent-resistant and detergent-soluble domains in rod outer segment plasma membranes and disks
Differential distribution of proteins and lipids in detergent-resistant and detergent-soluble domains in rod outer segment plasma membranes and disks
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DOI：
10.1111/j.1471-4159.2007.04971.x
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发表时间：
2008-01-01
影响因子：
4.7
通讯作者：
Naash, Muna I.
中科院分区：
文献类型：
--
作者：
Elliott, Michael H.;Nash, Zack A.;Naash, Muna I.
细胞膜的异质性在调节细胞信号转导和其他细胞活动中起着重要的作用。我们研究了与来自视网膜杆外段（ROS）盘和质膜富集制剂的抗洗涤剂膜（DRM）组分相关的蛋白质和脂质组分。蛋白质组学和相关的蛋白质印迹分析揭示了α和β亚基的杆cGMP门控离子通道和葡萄糖转运蛋白1型，以及其他蛋白质的存在。葡萄糖转运蛋白仅存在于ROS质膜（而不是圆盘）中，并在DRM中高度富集，cGMP门控通道β亚基也是如此。与此相反，大多数视杆视蛋白和ATP结合盒转运蛋白A4本地化的洗涤剂可溶性结构域的磁盘。正如预期的那样，胆固醇：脂肪酸摩尔比在DRM中高于相应的母体膜（分别为磁盘和质膜），并且与质膜相比，磁盘中的胆固醇：脂肪酸摩尔比也较高。此外，饱和：多不饱和脂肪酸的比例也较高的DRM相比，其各自的母膜（磁盘和质膜）。这些结果证实，与其母膜相比，由圆盘和质膜制备的DRM富含胆固醇和饱和脂肪酸。DRMs中的主要脂肪酸为16：0和18：0; 22：6 n3和18：1水平分别为3倍高和2倍低，相比质膜衍生的DRMs，在磁盘衍生的DRMs。我们估计，基于脂肪酸回收，DRM仅占磁盘的8%和ROS质膜的12%。
Membrane heterogeneity plays a significant role in regulating signal transduction and other cellular activities. We examined the protein and lipid components associated with the detergent-resistant membrane (DRM) fractions from retinal rod outer segment (ROS) disk and plasma membrane-enriched preparations. Proteomics and correlative western blot analysis revealed the presence of alpha and beta subunits of the rod cGMP-gated ion channel and glucose transporter type 1, among other proteins. The glucose transporter was present exclusively in ROS plasma membrane (not disks) and was highly enriched in DRMs, as was the cGMP-gated channel beta-subunit. In contrast, the majority of rod opsin and ATP-binding cassette transporter A4 was localized to detergent-soluble domains in disks. As expected, the cholesterol : fatty acid mole ratio was higher in DRMs than in the corresponding parent membranes (disk and plasma membranes, respectively) and was also higher in disks compared to plasma membranes. Furthermore, the ratio of saturated : polyunsaturated fatty acids was also higher in DRMs compared to their respective parent membranes (disk and plasma membranes). These results confirm that DRMs prepared from both disks and plasma membranes are enriched in cholesterol and in saturated fatty acids compared to their parent membranes. The dominant fatty acids in DRMs were 16 : 0 and 18 : 0; 22 : 6n3 and 18 : 1 levels were threefold higher and twofold lower, respectively, in disk-derived DRMs compared to plasma membrane-derived DRMs. We estimate, based on fatty acid recovery that DRMs account for only similar to 8% of disks and similar to 12% of ROS plasma membrane.