All cells depend on efficient targeting of specific proteins to their correct intracellular locations. In the secretory pathway this is carried out by vesicular transport. Little is known about the membrane components involved in vesicular transport primarily due to the difficulty of dissecting and reconstituting such a complex process. Recently, in vitro reconstitution of membrane transport steps have allowed the first insights into cytosolic components which are required for transport between Golgi cisternae. The objective of the research described in this proposal is the further development of cell-free systems to reconstitute the sorting of molecules and the formation of transport vesicles from the trans Golgi network and their correct targeting to the plasma membrane. Specifically, the components that are involved in the sorting, vesicle formation and vesicle targeting will be identified and characterized. The cell-free system we introduce to study vesicular transport from the trans Golgi network starts with an isolated organelle, a stacked Golgi fraction which is immobilized on the surface of a magnetic bead by an antigen/antibody interaction (immunoisolation). Transport vesicles are generated from the trans Golgi network under conditions where the recipient organelles are not present and the donor organelle can be rapidly removed since it is bound to a magnetic solid support. The intermediates in the traffic event, the transport vesicles, will be isolated from the budded fraction using specific antibodies. In a consequent set of experiments, recipient membranes will be added and the fusion process will be studied. Biochemical dissection and immunological reagents will be applied to analyze the two sub-cellular compartments involved in the transport to the cell surface: the trans Golgi network and the transport vesicles. Both cytosolic and membrane proteins involved in the traffic process will be sought and their interactions studied. Verification of the specificity of these proteins in the transport process will be accomplished by reintroducing them into our cell-free systems.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM042629-02
Application #
3301356
Study Section
Cellular Biology and Physiology Subcommittee 1 (CBY)
Project Start
1990-04-01
Project End
1995-03-31
Budget Start
1991-04-01
Budget End
1992-03-31
Support Year
2
Fiscal Year
1991
Total Cost
Indirect Cost
Name
University of Colorado Denver
Department
Type
Schools of Medicine
DUNS #
065391526
City
Aurora
State
CO
Country
United States
Zip Code
80045
Marsh, Brad J (2007) Reconstructing mammalian membrane architecture by large area cellular tomography. Methods Cell Biol 79:193-220
Snyder, Christopher M; Mardones, Gonzalo A; Ladinsky, Mark S et al. (2006) GMx33 associates with the trans-Golgi matrix in a dynamic manner and sorts within tubules exiting the Golgi. Mol Biol Cell 17:511-24
Mogelsvang, Soren; Howell, Kathryn E (2006) Global approaches to study Golgi function. Curr Opin Cell Biol 18:438-43
Mardones, Gonzalo A; Snyder, Christopher M; Howell, Kathryn E (2006) Cis-Golgi matrix proteins move directly to endoplasmic reticulum exit sites by association with tubules. Mol Biol Cell 17:525-38
Thompson, Roger J; Akana, Hillary C S R; Finnigan, Claire et al. (2006) Anion channels transport ATP into the Golgi lumen. Am J Physiol Cell Physiol 290:C499-514
Fouassier, Laura; Nichols, Matthew T; Gidey, Elizabeth et al. (2005) Protein kinase C regulates the phosphorylation and oligomerization of ERM binding phosphoprotein 50. Exp Cell Res 306:264-73
Wu, Christine C; MacCoss, Michael J; Howell, Kathryn E et al. (2004) Metabolic labeling of mammalian organisms with stable isotopes for quantitative proteomic analysis. Anal Chem 76:4951-9
Mogelsvang, Soren; Marsh, Brad J; Ladinsky, Mark S et al. (2004) Predicting function from structure: 3D structure studies of the mammalian Golgi complex. Traffic 5:338-45
Marsh, Brad J; Volkmann, Niels; McIntosh, J Richard et al. (2004) Direct continuities between cisternae at different levels of the Golgi complex in glucose-stimulated mouse islet beta cells. Proc Natl Acad Sci U S A 101:5565-70
Wu, Christine C; MacCoss, Michael J; Mardones, Gonzalo et al. (2004) Organellar proteomics reveals Golgi arginine dimethylation. Mol Biol Cell 15:2907-19

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