Caveolin 3, Flotillin 1 and Influenza Virus Hemagglutinin Reside in Distinct Domains on the Sarcolemma of Skeletal Myofibers
Figure 2
Cav 3 and flotillin 1 reside in different types of rafts. Cav 3 (red) normally exhibits a cross-striated distribution pattern over the I bands, while flotillin 1 (green) locates to the A-band regions lacking cav 3 (a). A confocal section 5 μm beneath the sarcolemma shows neither flotillin 1 nor cav 3 (b). A confocal section at the middle of the myofiber shows flotillin and cav 3 on the sarcolemma exclusively (c). After treatment with 5 mM CDX, the sarcolemmal staining patterns retain (d), however, a confocal section 5 μm beneath the sarcolemma of the CDX-treated myofiber reveals double rows of dots of cav 3 (e). Some subsarcolemmal dots are also visible in the middle section (f). Scale bars, 2 μm. The flotillin and cav 3 staining patterns were abolished upon omitting the primary antibodies (g). EM immunogold labeling of FDB cryosections shows particles indicating the presence of cav 3 predominantly in the sarcolemma in myofibers not treated with CDX (h). In FDB myofiber treated with 5 mM CDX, the immunogold particles are associated with the transverse tubules, marked by dotted lines (i). Scale bar in (h, i) 250 nm.
