The membrane-spanning domains of caveolins-1 and-2 mediate the formation of gaveolin hetero-oligomers - Implications for the assembly of caveolae membranes in vivo
K. Das et al., The membrane-spanning domains of caveolins-1 and-2 mediate the formation of gaveolin hetero-oligomers - Implications for the assembly of caveolae membranes in vivo, J BIOL CHEM, 274(26), 1999, pp. 18721-18728
The mammalian caveolin gene family consists of caveolins-1, -2, and -3. The
expression of caveolin-3 is muscle-specific. In contrast, caveolins-1 and
-2 are co-expressed, and they form a hetero-oligomeric complex in many cell
types, with particularly high levels in adipocytes, endothelial cells, and
fibroblasts. These caveolin hetero-oligomers are thought to represent the
functional assembly units that drive caveolae formation in vivo. Here, we i
nvestigate the mechanism by which caveolins-1 and -2 form hetero-oligomers.
We reconstituted this reciprocal interaction in vivo and in vitro using a
variety of complementary approaches, including the generation of glutathion
e S-transferase fusion proteins and synthetic peptides. Taken together, our
results indicate that the membrane-spanning domains of both caveolins-1 an
d -2 play a critical role in mediating their ability to interact with each
other. This is the first demonstration that these unusual membrane-spanning
regions found in the caveolin family play a specific role in protein-prote
in interactions.