INSIGHTS INTO SECRETORY AND ENDOCYTIC MEMBRANE TRAFFIC USING GREEN FLUORESCENT PROTEIN CHIMERAS

Green fluorescent fusion proteins, which can be visualized in the unpe rturbed environment of a living cell, have become important reporter m olecules for studying protein localization and trafficking within secr etory and endocytic membranes of living cells. They have been used in a wide variety of applications, including time-lapse imaging, double-l abeling and photobleach experiments. Results from such work are clarif ying the steps involved in the formation, translocation and fusion of transport intermediates, are defining the roles for microtubules in me mbrane transport, and are providing insights into the mechanisms of pr otein retention and localization within organelles. In so doing, they have changed our thinking about the temporal and spatial relationships between subcellular membrane structures and the morphogenesis of secr etory and endocytic organelles.