An electron microscopic study of TGN38/41 dynamics.
We have used electron microscopy to further characterize details of the dynamics of TGN38/41, a protein found to cycle between the trans-Golgi network and the plasma membrane. Immunogold-labeling of NRK cells under steady-state conditions shows the majority of TGN38/41 is localized to the trans-most Golgi cisternae and the trans-Golgi network. Small amounts of this molecule can be detected in early endosomes. Capture of cycling TGN38/41 molecules at the cell surface altered the steady state distribution. This was accomplished by binding TGN38/41 luminal domain antibodies to solid supports (beads), which were introduced to the culture media of cells. As increasing numbers of antigen-antibody complexes formed, the beads were internalized by the 'zippering mechanism' of phagocytosis. This provides a system that can address many questions related to the function of TGN38/41 and the trans-Golgi network itself.
Ladinsky
M S
MS
Department of Cellular and Structural Biology, University of Colorado School of Medicine, Denver 80262.
Howell
K E
KE
D000818:Animals; D001693:Biological Transport, Active; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism / Q000648:ultrastructure; D016764:Cell Polarity / Q000502:physiology*; D004705:Endocytosis; D006023:Glycoproteins; D006056:Golgi Apparatus / Q000378:metabolism* / Q000648:ultrastructure*; D007668:Kidney / Q000378:metabolism / Q000648:ultrastructure; D008562:Membrane Glycoproteins / Q000378:metabolism*; D008565:Membrane Proteins; D016253:Microscopy, Immunoelectron; D051381:Rats
D006023:Glycoproteins; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; C513045:Tgoln2 protein, rat