Translocation of histone proteins across lipid bilayers and mycoplasma membranes
Translocation of histone proteins across lipid bilayers and mycoplasma membranes
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DOI：
10.1016/j.jmb.2004.10.046
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发表时间：
2005-01-14
影响因子：
5.6
通讯作者：
Loyter, A
中科院分区：
文献类型：
--
作者：
Rosenbluh, J;Hariton-Gazal, E;Loyter, A
我们发现，三个核心组蛋白H2 A，H3和H4可以横向脂质双层的大单层囊泡（LUV）和多层囊泡（MLV）。相比之下，组蛋白H2 B，虽然能够结合到脂质体，未能穿透单层和多层囊泡。使用生物素标记的组蛋白和基于ELISA的系统确定跨脂质双层的易位。与脂质体孵育后，通过加入抗生物素蛋白来中和外膜结合的生物素分子。通过Triton处理中和的脂质体暴露穿透的生物素-组蛋白缀合物。脂质体内的生物素-组蛋白缀合物，与那些只连接到外表面，连接到洗涤剂裂解的脂质分子。因此，仅在脂质体经过去污剂处理后才暴露的生物素化组蛋白分子被认为位于脂质双层的内小叶处。穿透组蛋白分子未能介导共价连接到它们的BSA分子的易位。还观察到核心组蛋白（包括H2 B）穿过支原体细胞膜的易位。这种易位的程度与膜胆固醇的程度呈负相关。胆固醇的添加也降低了组蛋白渗透到MLV中的程度。虽然能够结合生物素化的组蛋白，人类红细胞，红细胞血影和大肠杆菌细胞是不可渗透的。基于目前和以前的数据，组蛋白似乎具有与细胞穿透肽和蛋白（CPP）相同的特征。(C)2004爱思唯尔有限公司保留所有权利。
We show that the three core histones H2A, H3 and H4 can transverse lipid bilayers of large unilamellar vesicles (LUVs) and multilamellar vesicles (MLVs). In contrast, the histone H2B, although able to bind to the liposomes, fails to penetrate the unilamellar and the multilamellar vesicles. Translocation across the lipid bilayer was determined using biotin-labeled histones and an ELISA-based system. Following incubation with the liposomes, external membrane-bound biotin molecules were neutralized by the addition of avidin. Penetrating biotin-histone conjugates were exposed by Triton treatment of the neutralized liposomes. The intra-liposomal biotin-histone conjugates, in contrast to those attached only to the external surface, were attached to the detergent lysed lipid molecules. Thus, biotinylated histone molecules that were exposed only following detergent treatment of the liposomes were considered to be located at the inner leaflet of the lipid bilayers. The penetrating histone molecules failed to mediate translocation of BSA molecules covalently attached to them. Translocation of the core histones, including H2B, was also observed across mycoplasma cell membranes. The extent of this translocation was inversely related to the degree of membrane cholesterol. The addition of cholesterol also reduced the extent of histone penetration into the MLVs. Although able to bind biotinylated histones, human erythrocytes, erythrocyte ghosts and Escherichia coli cells were impermeable to them. Based on the present and previous data histones appear to be characterized by the same features that characterize cell penetrating peptides and proteins (CPPs). (C) 2004 Elsevier Ltd. All rights reserved.