Kinetic Analysis of Secretory Protein Traffic and Characterization of Golgi to Plasma Membrane Transport Intermediates in Living Cells

摘要: Quantitative time-lapse imaging data of single cells expressing the transmembrane protein, vesicular stomatitis virus ts045 G protein fused to green fluorescent (VSVG–GFP), were used for kinetic modeling traffic through various compartments secretory pathway. A series first order rate laws was sufficient accurately describe VSVG–GFP transport, and provided compartment residence times constants transport into out Golgi complex delivery plasma membrane. For ER mean constant (i.e., fraction moved per unit time) 2.8% min, membrane it 3.0% from a degradative site 0.25% min. Because these did not change as concentration in different went high (early experiment) low (late experiment), machinery never saturated during experiments. The processes budding, translocation, fusion post-Golgi intermediates carrying VSVG– GFP also analyzed using quantitative techniques. Large pleiomorphic tubular structures, rather than small vesicles, found be primary vehicles VSVG–GFP. These structures budded entire domains underwent dynamic shape changes they along microtubule tracks cell periphery. They carried up 10,000 molecules had life time COS 3.8 In addition, with without intersecting other pathways cell. properties suggest that represent unique organelle conveying large quantities cargo directly