Bovine caveolin-2 cloning and effects of shear stress on its localization in bovine aortic endothelial cells.
Caveolae are plasmalemmal domains enriched with cholesterol, caveolins, and signaling molecules. Normally, cells that express caveolin-1 also express caveolin-2, but this has not been demonstrated in bovine aortic endothelial cells (BAECs). Here, we show that BAECs express caveolin-2, which localizes in caveolae with caveolin-1. We have cloned the bovine caveolin-2 gene and after comparison with known protein sequences (human, murine, rat, and canine) have found divergent immunogenic regions (amino acid [aa] 21 to aa 50 and aa 79 to 88), which may explain the inability to detect caveolin-2 in different cell types. We developed a bovine caveolin-2-specific antibody to examine this protein's expression and localization in BAECs. We used differential gradient centrifugations and immunoprecipitation to show that bovine caveolin-2 and caveolin-1 form a hetero-oligomer in plasma membrane caveolae. Using immunocytochemistry we show that a pool of caveolin-2 also colocalizes with the cis-Golgi in static culture, but unlike caveolin-1, this Golgi associated pool is maintained after 1 day of shear exposure. Therefore, the interaction of caveolin-2 with caveolin-1 could play an important role in caveolae biogenesis and shear stimulated mechano-signal transduction.
Boyd
Nolan
N
Wallace H. Coulter Department of Biomedical Engineering at Georgia Tech and Emory University, Atlanta, Georgia 30322, USA.
Park
Heonyong
H
Sun
Wen-Ping
WP
Coleman
Sarah
S
Cherukuri
Ramakrishna
R
Jo
Hanjoong
H
D000818:Animals; D000918:Antibody Specificity / Q000235:genetics / Q000276:immunology; D001011:Aorta / Q000166:cytology / Q000378:metabolism*; D002417:Cattle; D021941:Caveolae / Q000378:metabolism*; D051242:Caveolin 1; D051243:Caveolin 2; D022461:Caveolins / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism*; D002460:Cell Line; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000032:analysis / Q000235:genetics; D004285:Dogs; D004730:Endothelium, Vascular / Q000378:metabolism*; D006056:Golgi Apparatus / Q000378:metabolism; D006801:Humans; D046911:Macromolecular Substances / Q000378:metabolism; D040542:Mechanotransduction, Cellular / Q000502:physiology*; D051379:Mice; D008969:Molecular Sequence Data; D011485:Protein Binding / Q000502:physiology; D012039:Regional Blood Flow / Q000502:physiology; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid; D013314:Stress, Mechanical
C495540:CAV1 protein, human; C495541:Cav1 protein, mouse; D051242:Caveolin 1; D051243:Caveolin 2; D022461:Caveolins; D018076:DNA, Complementary; D046911:Macromolecular Substances