Activators of protein kinase A stimulate apical but not basolateral transport in epithelial Madin-Darby canine kidney cells.
In polarized Madin-Darby canine kidney cells the newly synthesized plasma membrane proteins, on the exocytic pathway, are sorted in the trans-Golgi network (TGN) and delivered directly to the apical or basolateral surface. Forskolin, isobutylmethylxanthine, and dibutyryl cAMP, all known to activate protein kinase A, stimulated transport of influenza hemagglutinin (HA) from the TGN to the apical surface. The same reagents, however, did not affect the transport of HA from the endoplasmic reticulum to the Goli complex nor did they affect transport of vesicular stomatitis virus G protein from the TGN to the basolateral surface. The addition of staurosporin, a general protein kinase inhibitor, did not affect the transport of HA in nontreated cells but blocked the stimulation caused by the above reagents. Apical transport of HA was also stimulated by phorbol ester, an activator of protein kinase C. Activation of apical transport by phorbol ester as well as aluminum fluoride (Pimplikar, S. W., and Simons, K. (1993) Nature 362, 456-458) was also negated by staurosporin. These results show that in polarized Madin-Darby canine kidney cells, protein kinase A and protein kinase C selectively stimulate the apical transport.
Cell Biology Program, European Molecular Biology Laboratory, Heidelberg, Federal Republic of Germany.
S W
SW
Pimplikar
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K
Simons
D000470:Alkaloids / Q000494:pharmacology; D017607:Aluminum Compounds / Q000494:pharmacology; D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D016764:Cell Polarity; D005576:Colforsin / Q000494:pharmacology; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism*; D004285:Dogs; D004721:Endoplasmic Reticulum / Q000378:metabolism; D004789:Enzyme Activation / Q000187:drug effects; D004848:Epithelium / Q000378:metabolism*; D005459:Fluorides / Q000494:pharmacology; D019204:GTP-Binding Proteins / Q000378:metabolism; D006056:Golgi Apparatus / Q000378:metabolism; D006388:Hemagglutinins / Q000378:metabolism; D066298:In Vitro Techniques; D007668:Kidney; D008562:Membrane Glycoproteins; D015240:Phorbol 12,13-Dibutyrate / Q000494:pharmacology; D010750:Phosphoproteins / Q000378:metabolism; D019311:Staurosporine; D014759:Viral Envelope Proteins / Q000378:metabolism
D000470:Alkaloids; D017607:Aluminum Compounds; C028391:G protein, vesicular stomatitis virus; D006388:Hemagglutinins; D008562:Membrane Glycoproteins; D010750:Phosphoproteins; D014759:Viral Envelope Proteins; D005576:Colforsin; D015240:Phorbol 12,13-Dibutyrate; D017868:Cyclic AMP-Dependent Protein Kinases; D019204:GTP-Binding Proteins; D019311:Staurosporine; D005459:Fluorides; C032311:aluminum fluoride