TGN38/41 recycles between the cell surface and the TGN: brefeldin A affects its rate of return to the TGN.
TGN38 and TGN41 are isoforms of an integral membrane protein (TGN38/41) that is predominantly localized to the trans-Golgi network (TGN) of normal rat kidney cells. Polyclonal antisera to TGN38/41 have been used to monitor its appearance at, and removal from, the surface of control and Brefeldin A (BFA)-treated cells. Antibodies that recognize the lumenal domain of TGN38/41 are capable of specific binding to the surface of both control and BFA-treated cells. In both control and BFA-treated cells internalized TGN38/41 is targeted to the TGN; however, there are differences in 1) the morphology of the intracellular structures through which TGN38/41 passes and 2) the kinetics of internalization. These data demonstrate that TGN38/41 cycles between the plasma membrane and the TGN in control and BFA-treated cells and suggest that recycling pathways between the plasma membrane and the TGN exist for predominantly TGN proteins as well as those that normally cycle to other intracellular compartments. They also demonstrate that addition of BFA not only alters the morphology and localization of the TGN but also the kinetics of endocytosis.
Reaves
B
B
Department of Biochemistry, School of Medical Sciences, University of Bristol, United Kingdom.
Horn
M
M
Banting
G
G
D000818:Animals; D020126:Brefeldin A; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D002478:Cells, Cultured; D003517:Cyclopentanes / Q000494:pharmacology*; D004705:Endocytosis / Q000187:drug effects; D005455:Fluorescent Antibody Technique; D006023:Glycoproteins; D006056:Golgi Apparatus / Q000187:drug effects / Q000378:metabolism; D007700:Kinetics; D008562:Membrane Glycoproteins / Q000378:metabolism*; D008565:Membrane Proteins; D008870:Microtubules / Q000187:drug effects / Q000378:metabolism; D051381:Rats
D003517:Cyclopentanes; D006023:Glycoproteins; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; C513045:Tgoln2 protein, rat; D020126:Brefeldin A