Role of caveolin and caveolae in insulin signaling and diabetes.
Caveolae are specialized membrane microdomains present within the plasma membrane of the vast majority of cell types. They have a unique composition in that they are highly enriched in cholesterol, sphingolipids, and their coat proteins the caveolins (-1, -2, and -3). In recent years it has been recognized that caveolae act as signaling platforms, serving as a concentrating point for numerous signaling molecules, as well as regulating flux through many distinct signaling cascades. Although caveolae are found in a variety of cell types, they are most abundant in adipose tissue. This fact has led to the intense study of the function of these organelles in adipocytes. It has now become apparent that effective insulin signaling in the adipocyte may be strictly dependent on localization of at least two insulin-responsive elements to caveolae (insulin receptor and GLUT4), as well as on a direct functional interaction between caveolin-1 and the insulin receptor. We present a critical discussion of these recent findings.
Cohen
Alex W
AW
Department of Molecular Pharmacology, Albert Einstein Diabetes Research and Training Center, Albert Einstein College of Medicine, 1300 Morris Park Ave., Bronx, NY 10461, USA.
Combs
Terry P
TP
Scherer
Philipp E
PE
Lisanti
Michael P
MP
D000273:Adipose Tissue / Q000378:metabolism*; D000818:Animals; D021941:Caveolae / Q000378:metabolism*; D051242:Caveolin 1; D022461:Caveolins / Q000378:metabolism*; D003920:Diabetes Mellitus / Q000378:metabolism*; D051275:Glucose Transporter Type 4; D006801:Humans; D007328:Insulin / Q000378:metabolism*; D007333:Insulin Resistance; D009004:Monosaccharide Transport Proteins / Q000378:metabolism; D009124:Muscle Proteins; D011972:Receptor, Insulin / Q000378:metabolism*; D015398:Signal Transduction
C495540:CAV1 protein, human; D051242:Caveolin 1; D022461:Caveolins; D051275:Glucose Transporter Type 4; D007328:Insulin; D009004:Monosaccharide Transport Proteins; D009124:Muscle Proteins; C495692:SLC2A4 protein, human; D011972:Receptor, Insulin