Different biosynthetic transport routes to the plasma membrane in BHK and CHO cells.
The question of how membrane proteins are delivered from the TGN to the cell surface in fibroblasts has received little attention. In this paper we have studied how their post-Golgi delivery routes compare with those in epithelia] cells. We have analyzed the transport of the vesicular stomatitis virus G protein, the Semliki Forest virus spike glycoprotein, both basolateral in MDCK cells, and the influenza virus hemagglutinin, apical in MDCK cells. In addition, we also have studied the transport of a hemagglutinin mutant (Cys543Tyr) which is basolateral in MDCK cells. Aluminum fluoride, a general activator of heterotrimeric G proteins, inhibited the transport of the basolateral cognate proteins, as well as of the hemagglutinin mutant, from the TGN to the cell surface in BHK and CHO cells, while having no effect on the surface delivery of the wild-type hemagglutinin. Only wild-type hemagglutinin became insoluble in the detergent CHAPS during transport through the BHK and CHO Golgi complexes, whereas the basolateral marker proteins remained CHAPS-soluble. We also have developed an in vitro assay using streptolysin O-permeabilized BHK cells, similar to the one we have previously used for analyzing polarized transport in MDCK cells (Pimplikar, S.W., E. Ikonen, and K. Simons. 1994. J. Cell Biol. 125:1025-1035). In this assay anti-NSF and rab-GDI inhibited transport of Semliki Forest virus spike glycoproteins from the TGN to the cell surface while having little effect on transport of the hemagglutinin. Altogether these data suggest that fibroblasts have apical and basolateral cognate routes from the TGN to the plasma membrane.
Yoshimori
T
T
European Molecular Biology Laboratory, Cell Biology Programme, Heidelberg, Federal Republic of Germany.
Keller
P
P
Roth
M G
MG
Simons
K
K
D017607:Aluminum Compounds / Q000494:pharmacology; D000818:Animals; D001426:Bacterial Proteins; D001692:Biological Transport / Q000187:drug effects; D016466:CHO Cells; D002352:Carrier Proteins / Q000502:physiology; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism*; D002463:Cell Membrane Permeability; D016764:Cell Polarity; D006224:Cricetinae; D004848:Epithelium / Q000378:metabolism; D005459:Fluorides / Q000494:pharmacology; D019204:GTP-Binding Proteins / Q000502:physiology; D006056:Golgi Apparatus / Q000378:metabolism*; D020730:Guanine Nucleotide Dissociation Inhibitors; D019267:Hemagglutinin Glycoproteins, Influenza Virus; D006389:Hemagglutinins, Viral / Q000235:genetics / Q000378:metabolism; D008562:Membrane Glycoproteins; D052066:N-Ethylmaleimide-Sensitive Proteins; D013301:Streptolysins / Q000494:pharmacology; D033921:Vesicular Transport Proteins; D014759:Viral Envelope Proteins / Q000378:metabolism*
D017607:Aluminum Compounds; D001426:Bacterial Proteins; D002352:Carrier Proteins; C028391:G protein, vesicular stomatitis virus; C086796:GDP dissociation inhibitor 1; D020730:Guanine Nucleotide Dissociation Inhibitors; D019267:Hemagglutinin Glycoproteins, Influenza Virus; D006389:Hemagglutinins, Viral; D008562:Membrane Glycoproteins; D013301:Streptolysins; D033921:Vesicular Transport Proteins; D014759:Viral Envelope Proteins; C025964:streptolysin O; D019204:GTP-Binding Proteins; D052066:N-Ethylmaleimide-Sensitive Proteins; D005459:Fluorides; C032311:aluminum fluoride