Cell-specific targeting of caveolin-1 to caveolae, secretory vesicles, cytoplasm or mitochondria.
In commonly used tissue culture cells, caveolin-1 is embedded in caveolae membranes. It appears to reach this location after being cotranslationally inserted into ER membranes, processed in the Golgi and shipped to the cell surface. We now report that caveolae are not the preferred location for caveolin-1 in all cell types. Skeletal muscle cells and keratinocytes target caveolin-1 to the cytosol while in exocrine and endocrine cells it accumulates in the secretory pathway. We also found that airway epithelial cells accumulate caveolin-1 in modified mitochondria. The cytosolic and the secreted forms appear to be incorporated into a soluble, lipid complex. We conclude that caveolin-1 can be targeted to a variety of intracellular destinations, which suggests a novel mechanism for the intracellular traffic of this protein.
Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9039, USA.
W P
WP
Li
P
P
Liu
B K
BK
Pilcher
R G
RG
Anderson
D000328:Adult; D000818:Animals; D051242:Caveolin 1; D022461:Caveolins / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism; D002478:Cells, Cultured; D003593:Cytoplasm / Q000378:metabolism; D004847:Epithelial Cells / Q000378:metabolism; D006801:Humans; D015603:Keratinocytes / Q000166:cytology; D051379:Mice; D008810:Mice, Inbred C57BL; D008928:Mitochondria / Q000378:metabolism; D018482:Muscle, Skeletal / Q000166:cytology; D051381:Rats; D017207:Rats, Sprague-Dawley; D020545:Respiratory Mucosa / Q000166:cytology; D022142:Secretory Vesicles / Q000378:metabolism
C495540:CAV1 protein, human; C495541:Cav1 protein, mouse; C495537:Cav1 protein, rat; D051242:Caveolin 1; D022461:Caveolins