BIO-2600 Lecture Notes - Lecture 4: High Fidelity, Triskelion, Dynamin
27 Feb 2018
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Document Summary
Cell biology was invented by scientists who pioneered microscopic cell imaging techniques as well as the ability to fractionate, isolate, and characterize all the unique entities that lie within. In the context of the endomembrane system, the presence of common er signal sequences does not necessarily mean permanent co-occupancy in that compartment. Most proteins translocated in the er ultimately have other destinations in the cell. Vesicle trafficking, by definition, describes the shipping and receiving of proteins throughout the cell by a high fidelity mechanism of cargo loading, budding from donor compartments, transport in the cytoplasm, and fusion with defined targets. A yeast vacuole fusion system can be used to identify and characterize vesicle trafficking (fusion) machinery. To identify fusion machinery, cytosolic proteins are first fractionated and then ultimately purified according to their unique properties. Fractionation of cytosolic proteins revealed two peaks of fusogenic activity: hma (high molecular weight activity) and lma (low molecular weight activity).
