Caveolin-1 is not essential for biosynthetic apical membrane transport.
Caveolin-1 has been implicated in apical transport of glycosylphosphatidylinositol (GPI)-anchored proteins and influenza virus hemagglutinin (HA). Here we have studied the role of caveolin-1 in apical membrane transport by generating caveolin-1-deficient Madin-Darby canine kidney (MDCK) cells using retrovirus-mediated RNA interference. The caveolin-1 knockdown (cav1-KD) MDCK cells were devoid of caveolae. In addition, caveolin-2 was retained in the Golgi apparatus in cav1-KD MDCK cells. However, we found no significant alterations in the apical transport kinetics of GPI-anchored proteins or HA upon depletion of caveolin-1. Similar results were obtained using embryonic fibroblasts from caveolin-1-knockout mice. Thus, we conclude that caveolin-1 does not play a major role in lipid raft-mediated biosynthetic membrane trafficking.
Manninen
Aki
A
Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, 01307 Dresden, Germany.
Verkade
Paul
P
Le Lay
Soazig
S
Torkko
Juha
J
Kasper
Michael
M
Füllekrug
Joachim
J
Simons
Kai
K
D000256:Adenoviridae / Q000378:metabolism; D000818:Animals; D001692:Biological Transport; D001710:Biotin / Q000737:chemistry; D019921:Biotinylation; D051242:Caveolin 1 / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D051243:Caveolin 2 / Q000235:genetics / Q000378:metabolism; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D002784:Cholesterol / Q000378:metabolism; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D005347:Fibroblasts / Q000378:metabolism; D017261:Glycosylphosphatidylinositols / Q000378:metabolism; D006056:Golgi Apparatus / Q000378:metabolism; D019267:Hemagglutinin Glycoproteins, Influenza Virus / Q000378:metabolism; D007150:Immunohistochemistry; D007700:Kinetics; D021962:Membrane Microdomains; D051379:Mice; D018345:Mice, Knockout; D008854:Microscopy, Electron; D008856:Microscopy, Fluorescence; D034622:RNA Interference; D012190:Retroviridae / Q000235:genetics / Q000378:metabolism; D013696:Temperature; D013997:Time Factors; D019076:Transgenes
D051242:Caveolin 1; D051243:Caveolin 2; D017261:Glycosylphosphatidylinositols; D019267:Hemagglutinin Glycoproteins, Influenza Virus; D001710:Biotin; D002784:Cholesterol