Dissection of the Golgi complex. II. Density separation of specific Golgi functions in virally infected cells treated with monensin.

作者：Paul S. Quinn, Gillian M. Griffiths, William George Warren · 发表于：The Journal of Cell Biology · 年份：1983 · DOI：10.1083/jcb.96.3.851 · 被引用次数：146 · 研究领域：Mosquito-borne diseases and control、Cellular transport and secretion、Insect Resistance and Genetics

In the accompanying paper (Griffiths, G., P. Quinn, and G. Warren, 1983, J. Cell Biol., 96:835-850), we suggested that the Golgi stack could be divided into functionally distinct cis, medial, and trans compartments, each comprising one or two adjacent cisternae. These compartments were identified using Baby hamster kidney (BHK) cells infected with Semliki Forest virus (SFV) and treated with monensin. This drug blocked intracellular transport but not synthesis of the viral membrane proteins that were shown to accumulate in the medial cisternae. In consequence, these cisternae bound nucleocapsids. Here we show that this binding markedly increased the density of the medial cisternae and allowed us to separate them from cis and trans Golgi cisternae. A number of criteria were used to show that the intracellular capsid-binding membranes (ICBMs) observed in vivo were the same as those membranes sedimenting to a higher density in sucrose gradients in vitro, and this separation of cisternae was then used to investigate the distribution, within the Golgi stack, of some specific Golgi functions. After labeling for 2.5 min with [3H]palmitate, most of the fatty acid attached to viral membrane proteins was found in the ICBM fraction. Because the viral membrane proteins appear to move from cis to trans, this suggests that fatty acylation occurs in the cis or medial Golgi cisternae. In contrast, the distribution of alpha 1-2-mannosidase, an enzyme involved in trimming high-mannose oligosacc...