Inhibitors that block both the internalization of caveolae and the return of plasmalemmal vesicles.
Inhibitors that block both the internalization of caveolae and the return of plasmalemmal vesicles.
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DOI：
10.1101/sqb.1995.060.01.028
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发表时间：
1995
期刊：
影响因子：
--
通讯作者：
E. Smart;K. Estes;R.G.W. Anderson
中科院分区：
文献类型：
--
作者：
E. Smart;K. Estes;R.G.W. Anderson
胞吞作用是一种内吞过程，将小分子或离子浓缩并递送至细胞内部（安德森等人，1992）。在某些情况下，分子或离子是细胞生存所需的营养素（Kamen和Capdevila 1986）。其他时候，它可能是一种信号分子，提供有关细胞环境的关键信息（安德森1993）。胞饮作用的内在化载体是小窝（Rothberg et al. 1990 b）。形态学研究证明，小窝是一种动态细胞器，能够通过形成质膜小泡从细胞外环境中隔离物质（Simionescu 1983; Parton et al. 1994）。这些囊泡通常不与来自其他内吞途径的囊泡融合，并且在一些细胞中，甚至可能不从质膜分离。最终，这些囊泡回到细胞表面并完成内化循环。它们有一个特征性的膜被，装饰细胞质表面。这种被膜中的一种分子是一种称为小窝蛋白的膜蛋白（Rothberg et al. 1992）。形态学和生物化学实验均表明，小窝也是多种GPI锚定膜蛋白的聚集位点（Ying et al. 1992; Chang et al. 1994; Smart et al. 1995 b）。GPI锚定蛋白浓缩并加工在内化过程中被隔离在小窝中的分子（安德森1993）。最后，小窝似乎具有不同于周围质膜的脂质组成。小窝富含胆固醇（Simionescu et al. 1983; Rothberg et al. 1990 a; Smart et al. 1994 a）、鞘磷脂（Liu and安德森1995）和神经节苷脂（Parton 1994）。已经发现胆固醇是小窝结构（Rothberg et al. 1990 a）和功能（Chang et al. 1992）所必需的。
Potocytosis is an endocytotic process that concentrates and delivers small molecules or ions to the cell interior (Anderson et al. 1992). In some cases, the molecule or ion is a nutrient (Kamen and Capdevila 1986) that the cell needs for viability. Other times, it may be a signaling molecule that provides critical information about the cellular environment (Anderson 1993). The internalization vehicle for potocytosis is the caveola (Rothberg et al. 1990b). Morphological studies have documented that caveolae are dynamic organelles capable of sequestering material from the extracellular environment by forming plasmalemmal vesicles (Simionescu 1983; Parton et al. 1994). These vesicles often do not fuse with vesicles derived from other endocytotic pathways and, in some cells, may not even detach from the plasma membrane. Eventually, these vesicles return to the cell surface and complete the internalization cycle.The molecular composition of caveolae is beginning to be elucidated. They have a characteristic membrane coat that decorates the cytoplasmic surface. One of the molecules in this coat is an integral membrane protein called caveolin (Rothberg et al. 1992). Both morphological and biochemical experiments suggest that caveolae are also the collecting site for multiple GPI-anchored membrane proteins (Ying et al. 1992; Chang et al. 1994; Smart et al. 1995b). GPI-anchored proteins concentrate and process molecules that become sequestered in caveolae during internalization (Anderson 1993). Finally, caveolae appear to have a lipid composition that differs from the surrounding plasma membrane. Caveolae are enriched in cholesterol (Simionescu et al. 1983; Rothberg et al. 1990a; Smart et al. 1994a), sphingomyelin (Liu and Anderson 1995), and gangliosides (Parton 1994). Cholesterol has been found to be required for both the structure (Rothberg et al. 1990a) and the function (Chang et al. 1992) of caveolae.